Stian Ellefsen

• Lian, Kristian; Hammarström, Daniel; Hamarsland, Håvard; Mølmen, Knut Sindre; Moen, Sara Christine & Ellefsen, Stian (2024). Glucose ingestion before and after resistance training sessions does not augment ribosome biogenesis in healthy moderately trained young adults. European Journal of Applied Physiology. ISSN 1439-6319. doi: 10.1007/s00421-024-05446-x.
• Vikmoen, Olav; Teien, Hilde Kristin; Tansø, Rita; Aandstad, Anders; Lander, Elise & Cumming, Kristoffer Toldnes [Show all 7 contributors for this article] (2023). Effects of a 10-d Military Field Exercise on Body Composition, Physical Performance, and Muscle Cells in Men and Women. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 56(4), p. 682–696. doi: 10.1249/MSS.0000000000003340. Show summary

  Purpose: To investigate the effects of a demanding military field exercise on physical performance, body composition and muscle cellular outcomes in men and women. Methods: Ten men (20.5 ± 0.5 years) and 8 women (21.4 ± 1.4 years) completed a 10-day field exercise consisting of extensive physical activity with food and sleep restriction. Acquisition of body composition, physical performance, blood and muscle biopsies samples were done before and 1,7 and 14 days after the exercise. Results: There were no sex differences in the response to the exercise. Body mass was decreased with 5.6 ± 1.8% and fat mass with 31 ± 11% during the exercise. Both were still reduced after 14 days (2.5 ± 2.3%, p˂0.001 and 12.5 ± 7.7%, p˂0.001 respectively). Isometric leg strength did not change. Peak leg extension torque at 240 °·s-1 and counter movement jump height were reduced with 4.6 ± 4.8% (p = 0.012) and 6.7 ± 6.2% (p˂0.001) respectively and was still reduced after 14 days (4.3 ± 4.2%, p = 0.002, and 4.1 ± 4.7%, p = 0.030). No changes occurred in fiber CSA, fiber types, proteins involved in calcium handling or HSP70. During the exercise, αB-crystallin levels decreased by 14 ± 19% (p = 0.024) in the cytosolic fraction and staining intensity on muscle sections tended to increase (17 ± 25%, p = 0.076). MuRF1 levels in the cytosolic fraction tended to decrease (19 ± 35%) and increased with 85 ± 105% (p = 0.003) in the cytoskeletal fraction 1 week after the exercise. Conclusions: The field exercise resulted in reduced body mass and physical performance in both sexes. The ability to produce force at high contraction velocities and explosive strength was more affected than isometric strength, but this was not related to any changes in fiber type composition, fiber area, Ca2+ handling or fiber type specific muscle damage.

• Farup, Per Grønaas; Hamarsland, Håvard; Mølmen, Knut Sindre; Ellefsen, Stian & Hestad, Knut (2023). The Kynurenine Pathway in Healthy Subjects and Subjects with Obesity, Depression and Chronic Obstructive Pulmonary Disease. Pharmaceuticals. ISSN 1424-8247. 16(3). doi: 10.3390/ph16030351. Full text in Research Archive Show summary

  Background: Changes in tryptophan metabolism through the kynurenine pathway (KP) are observed in several disorders and coupled with pathophysiological deviations. Methods: This study retrospectively compared the KP in serum in healthy subjects (108) with subjects with obesity (141), depression (49), and chronic obstructive pulmonary disease (COPD) (22) participating in four clinical studies and explored predictors of the changes in the KP metabolites. Results: Compared with the healthy group, the KP was upregulated in the disease groups with high kynurenine, quinolinic acid (QA), kynurenine/tryptophan-ratio and QA/xanthurenic acid-ratio and low kynurenic acid/QA-ratio. Tryptophan and xanthurenic acid were upregulated in the depressed group compared with the groups with obesity and COPD. The covariates BMI, smoking, diabetes, and C-reactive protein explained the significant differences between the healthy group and the group with obesity but not between the healthy group and the groups with depression and COPD, indicating that different pathophysiological conditions result in the same changes in the KP. Conclusions: The KP was significantly upregulated in the disease groups compared with the healthy group, and there were significant differences between the disease groups. Different pathophysiological abnormalities seemed to result in the same deviations in the KP.

• Katare, Parmeshwar Bajirao; Dalmao Fernandez, Andrea; Mengeste, Abel Mulu; Hamarsland, Håvard; Ellefsen, Stian & Bakke, Hege Gilbø [Show all 9 contributors for this article] (2022). Energy metabolism in skeletal muscle cells from donors with different body mass index. Frontiers in Physiology. ISSN 1664-042X. 13. doi: 10.3389/fphys.2022.982842.
• Khan, Yusuf; Hammarström, Daniel; Ellefsen, Stian & Ahmad, Rafi (2022). Normalization of gene expression data revisited: the three viewpoints of the transcriptome in human skeletal muscle undergoing load-induced hypertrophy and why they matter. BMC Bioinformatics. ISSN 1471-2105. 23(1). doi: 10.1186/s12859-022-04791-y. Full text in Research Archive Show summary

  Background The biological relevance and accuracy of gene expression data depend on the adequacy of data normalization. This is both due to its role in resolving and accounting for technical variation and errors, and its defining role in shaping the viewpoint of biological interpretations. Still, the choice of the normalization method is often not explicitly motivated although this choice may be particularly decisive for conclusions in studies involving pronounced cellular plasticity. In this study, we highlight the consequences of using three fundamentally different modes of normalization for interpreting RNA-seq data from human skeletal muscle undergoing exercise-training-induced growth. Briefly, 25 participants conducted 12 weeks of high-load resistance training. Muscle biopsy specimens were sampled from m. vastus lateralis before, after two weeks of training (week 2) and after the intervention (week 12), and were subsequently analyzed using RNA-seq. Transcript counts were modeled as (1) per-library-size, (2) per-total-RNA, and (3) per-sample-size (per-mg-tissue). Result Initially, the three modes of transcript modeling led to the identification of three unique sets of stable genes, which displayed differential expression profiles. Specifically, genes showing stable expression across samples in the per-library-size dataset displayed training-associated increases in per-total-RNA and per-sample-size datasets. These gene sets were then used for normalization of the entire dataset, providing transcript abundance estimates corresponding to each of the three biological viewpoints (i.e., per-library-size, per-total-RNA, and per-sample-size). The different normalization modes led to different conclusions, measured as training-associated changes in transcript expression. Briefly, for 27% and 20% of the transcripts, training was associated with changes in expression in per-total-RNA and per-sample-size scenarios, but not in the per-library-size scenario. At week 2, this led to opposite conclusions for 4% of the transcripts between per-library-size and per-sample-size datasets (↑ vs. ↓, respectively). Conclusion Scientists should be explicit with their choice of normalization strategies and should interpret the results of gene expression analyses with caution. This is particularly important for data sets involving a limited number of genes or involving growing or differentiating cellular models, where the risk of biased conclusions is pronounced.

• Rønnestad, Bent; Urianstad, Thomas; Hamarsland, Håvard; Hansen, Joar; Nygård, Håvard & Ellefsen, Stian [Show all 8 contributors for this article] (2022). Heat Training Efficiently Increases and Maintains Hemoglobin Mass and Temperate Endurance Performance in Elite Cyclists. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 54(9), p. 1515–1526. doi: 10.1249/MSS.0000000000002928.
• Rønnestad, Bent; Lid, Ole Martin; Hansen, Joar; Hamarsland, Håvard; Mølmen, Knut Sindre & Nygård, Håvard [Show all 9 contributors for this article] (2022). Heat suit training increases hemoglobin mass in elite cross-country skiers. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. doi: 10.1111/sms.14156.
• Almquist, Nicki Winfield; Eriksen, Hanne Berg; Wilhelmsen, Malene; Hamarsland, Håvard; Ing, Steven Adolfo & Ellefsen, Stian [Show all 9 contributors for this article] (2022). No Differences Between 12 Weeks of Block- vs. Traditional-Periodized Training in Performance Adaptations in Trained Cyclists. Frontiers in Physiology. ISSN 1664-042X. 13. doi: 10.3389/fphys.2022.837634. Full text in Research Archive Show summary

  The purpose of this study was to compare the effects of 12 weeks load-matched block periodization (BP, n = 14), using weekly concentration of high- (HIT), moderate- (MIT), and low- (LIT) intensity training, with traditional periodization (TP, n = 16) using a weekly, cyclic progressive increase in training load of HIT-, MIT-, and LIT-sessions in trained cyclists (peak oxygen uptake: 58 ± 8 ml·kg−1·min−1). Red blood cell volume increased 10 ± 16% (p = 0.029) more in BP compared to TP, while capillaries around type I fibers increased 20 ± 12% (p = 0.002) more in TP compared to BP from Pre to Post12. No other group differences were found in time-trial (TT) performances or muscular-, or hematological adaptations. However, both groups improved 5 and 40-min TT power by 9 ± 9% (p < 0.001) and 8 ± 9% (p < 0.001), maximal aerobic power (Wmax) and power output (PO) at 4 mmol·L−1 blood lactate (W4mmol), by 6 ± 7 (p = 0.001) and 10 ± 12% (p = 0.001), and gross efficiency (GE) in a semi-fatigued state by 0.5 ± 1.1%-points (p = 0.026). In contrast, GE in fresh state and VO2peak were unaltered in both groups. The muscle protein content of β-hydroxyacyl (HAD) increased by 55 ± 58% in TP only, while both TP and BP increased the content of cytochrome c oxidase subunit IV (COXIV) by 72 ± 34%. Muscle enzyme activities of citrate synthase (CS) and phosphofructokinase (PFK) were unaltered. TP increased capillary-to-fiber ratio and capillary around fiber (CAF) type I by 36 ± 15% (p < 0.001) and 17 ± 8% (p = 0.025), respectively, while BP increased capillary density (CD) by 28 ± 24% (p = 0.048) from Pre to Post12. The present study shows no difference in performance between BP and “best practice”-TP of endurance training intensities using a cyclic, progressively increasing training load in trained cyclists. However, hematological and muscle capillary adaptations may differ.

• Oberholzer, Laura; Mølmen, Knut Sindre; Hammarström, Daniel; Falch, Gunnar Slettaløkken; Lundby, Anne-Kristine & Rønnestad, Bent [Show all 8 contributors for this article] (2022). Resistance exercise training increases skeletal muscle mitochondrial respiration in chronic obstructive pulmonary disease. JCSM Rapid Communications. 5. doi: 10.1002/rco2.58. Full text in Research Archive Show summary

  Chronic obstructive pulmonary disease (COPD) is associated with skeletal muscle mitochondrial dysfunc-tion. Resistance exercise training (RT) is a training modality with a relatively small pulmonary demand that has beensuggested to increase skeletal muscle oxidative enzyme activity in COPD. Whether a shift into a more oxidative profilefollowing RT also translates into increased mitochondrial respiratory capacity in COPD is yet to be established.

• Hammarström, Daniel; Øfsteng, Sjur Johansen; Jacobsen, Nicolai Blindheim; Flobergseter, Krister; Rønnestad, Bent & Ellefsen, Stian (2022). Ribosome accumulation during early phase resistance training in humans. Acta Physiologica. ISSN 1748-1708. 235(1). doi: 10.1111/apha.13806. Show summary

  Aim: To describe ribosome biogenesis during resistance training, its relation to training volume and muscle growth. Methods: A training group (n = 11) performed 12 sessions (3-4 sessions per week) of unilateral knee extension with constant and variable volume (6 and 3-9 sets per session respectively) allocated to either leg. Ribosome abundance and biogenesis markers were assessed from vastus lateralis biopsies obtained at baseline, 48 hours after sessions 1, 4, 5, 8, 9 and 12, and after eight days of de-training, and from a control group (n = 8). Muscle thickness was measured before and after the intervention. Results: Training led to muscle growth (3.9% over baseline values, 95% CrI: [0.2, 7.5] vs. control) with concomitant increases in total RNA, ribosomal RNA, upstream binding factor (UBF) and ribosomal protein S6 with no differences between volume conditions. Total RNA increased rapidly in response to the first four sessions (8.6% [5.6, 11.7] per session), followed by a plateau and peak values after session 8 (49.5% [34.5, 66.5] above baseline). Total RNA abundance was associated with UBF protein levels (5.0% [0.2, 10.2] per unit UBF), and the rate of increase in total RNA levels predicted hypertrophy (0.3 mm [0.1, 0.4] per %-point increase in total RNA per session). After de-training, total RNA decreased (-19.3% [-29.0, -8.1]) without muscle mass changes indicating halted biosynthesis of ribosomes. Conclusion: Ribosomes accumulate in the initial phase of resistance training with abundances sensitive to training cessation and associated with UBF protein levels. The average accumulation rate predicts muscle training-induced hypertrophy. Keywords: muscle hypertrophy; resistance training; ribosome biogenesis. © 2022 The Authors. Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society.

• Rønnestad, Bent; Bakken, Timo André; Thyli, Vetle; Hansen, Joar; Ellefsen, Stian & Hammarström, Jens Konrad Daniel (2021). Increasing Oxygen Uptake in Cross-Country 8 Skiers by Speed Variation in Work Intervals. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 17(3), p. 384–390. doi: 10.1123/ijspp.2021-0226. Show summary

  Purpose: Accumulated time at a high percentage of peak oxygen consumption (VO2peak) is important for improving performance in endurance athletes. The present study compared the acute physiological and perceived effects of performing high-intensity intervals with roller ski double poling containing work intervals with (1) fast start followed by decreasing speed (DEC), (2) systematic variation in exercise intensity (VAR), and (3) constant speed (CON). Methods: Ten well-trained cross-country skiers (double-poling VO2peak 69.6 [3.5] mL·min−1·kg−1) performed speed- and duration-matched DEC, VAR, and CON on 3 separate days in a randomized order (5 × 5-min work intervals and 3-min recovery). Results: DEC and VAR led to longer time ≥90% VO2peak (P = .016 and P = .033, respectively) and higher mean %VO2peak (P = .036, and P = .009) compared with CON, with no differences between DEC and VAR (P = .930 and P = .759, respectively). VAR, DEC, and CON led to similar time ≥90% of peak heart rate (HRpeak), mean HR, mean breathing frequency, mean ventilation, and mean blood lactate concentration ([La−]). Furthermore, no differences between sessions were observed for perceptual responses, such as mean rate of perceived exertion, session rate of perceived exertion or pain score (all Ps > .147). Conclusions: In well-trained XC skiers, DEC and VAR led to longer time ≥90% of VO2peak compared with CON, without excessive perceptual effort, indicating that these intervals can be a good alternative for accumulating more time at a high percentage of VO2peak and at the same time mimicking the pronounced variation in exercise intensities experienced during XC-skiing competitions.

• Almquist, Nicki Winfield; Wilhelmsen, Malene; Ellefsen, Stian; Sandbakk, Øyvind & Rønnestad, Bent (2021). Effects of including sprints in LIT sessions during a 14-d camp on muscle biology and performance measures in elite cyclists. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 53(11), p. 2333–2345. doi: 10.1249/MSS.0000000000002709. Full text in Research Archive Show summary

  Purpose This study investigated the effects of including sprints within low-intensity training (LIT) sessions during a 14-d training camp focusing on LIT, followed by 10-d recovery (Rec), on performance and performance-related measures in elite cyclists. Methods During the camp, a sprint training group (SPR; n = 9) included 12 × 30-s maximal sprints during five LIT sessions, whereas a control group (CON; n = 9) performed distance-matched LIT only. Training load was equally increased in both groups by 48% ± 27% during the training camp and subsequently decreased by −56% ± 23% during the recovery period compared with habitual training. Performance tests were conducted before the training camp (Pre) and after Rec. Muscle biopsies, hematological measures, and stress/recovery questionnaires were collected Pre and after the camp (Post). Results Thirty-second sprint (SPR vs CON: 4% ± 4%, P < 0.01) and 5-min mean power (SPR vs CON: 4% ± 8%, P = 0.04) changed differently between groups. In muscle, Na+-K+ β1 protein content changed differently between groups, decreasing in CON compared with SPR (−8% ± 14%, P = 0.04), whereas other proteins showed similar changes. SPR and CON displayed similar increases in red blood cell volume (SPR: 2.6% ± 4.7%, P = 0.07; CON: 3.9% ± 4.5%, P = 0.02) and V˙O2 at 4 mmol·L−1 [BLa−] (SPR: 2.5% ± 3.3%, P = 0.03; CON: 2.2% ± 3.0%, P = 0.04). No changes were seen for V˙O2max, Wmax, hematological measures, muscle enzyme activity, and stress/recovery measures. Conclusions Inclusion of 30-s sprints within LIT sessions during a high-volume training camp affected competition-relevant performance measures and Na+-K+ β1 protein content differently from LIT only, without affecting sport-specific stress/recovery or any other physiological measure in elite cyclists.

• Aaseth, Jan; Ellefsen, Stian; Alehagen, Urban; Sundfør, Tine M. & Alexander, Jan (2021). Diets and drugs for weight loss and health in obesity – An update. Biomedicine & Pharmacotherapy. ISSN 0753-3322. 140. doi: 10.1016/j.biopha.2021.111789. Full text in Research Archive Show summary

  Numerous combinations of diets and pharmacological agents, including lifestyle changes, have been launched to treat obesity. There are still ambiguities regarding the efficacies of different approaches despite many clinical trials and the use of animal models to study physiological mechanisms in weight management and obesity comorbidities, Here, we present an update on promising diets and pharmacological aids. Literature published after the year 2005 was searched in PubMed, Medline and Google scholar. Among recommended diets are low-fat (LF) and low-carbohydrate (LC) diets, in addition to the Mediterranean diet and the intermittent fasting approach, all of which presumably being optimized by adequate contents of dietary fibers. A basic point for weight loss is to adopt a diet that creates a permanently negative and acceptable energy balance, and prolonged dietary adherence is a crucial factor. As for pharmacological aids, obese patients with type 2 diabetes or insulin resistance seem to benefit from LC diet combined with a GLP-1 agonist, e.g. semaglutide, which may improve glycemic control, stimulate satiety, and suppress appetite. The lipase inhibitor orlistat is still used to maintain a low-fat approach, which may be favorable e.g. in hypercholesterolemia. The bupropion-naltrexone-combination appears promising for interruption of the vicious cycle of addictive over-eating. Successful weight loss seems to improve almost all biomarkers of obesity comorbidities. Until more support for specific strategies is available, clinicians should recommend an adapted lifestyle, and when necessary, a drug combination tailored to individual needs and comorbidities. Different diets may change hormonal secretion, gut-brain signaling, and influence hunger, satiety and energy expenditure. Further research is needed to clarify mechanisms and how such knowledge can be used in weight management.

• Mølmen, Knut Sindre; Hammarström, Jens Konrad Daniel; Falch, Gunnar Slettaløkken; Grundtvig, Morten; Koll, Lise & Hanestadhaugen, Marita [Show all 14 contributors for this article] (2021). Chronic obstructive pulmonary disease does not impair responses to resistance training. Journal of Translational Medicine. ISSN 1479-5876. 19. doi: 10.1186/s12967-021-02969-1. Full text in Research Archive Show summary

  Background: Subjects with chronic obstructive pulmonary disease (COPD) are prone to accelerated decay of muscle strength and mass with advancing age. This is believed to be driven by disease-inherent systemic pathophysiologies, which are also assumed to drive muscle cells into a state of anabolic resistance, leading to impaired abilities to adapt to resistance exercise training. Currently, this phenomenon remains largely unstudied. In this study, we aimed to investigate the assumed negative effects of COPD for health- and muscle-related responsiveness to resistance training using a healthy control-based translational approach. Methods: Subjects with COPD (n = 20, GOLD II-III, FEV1predicted 57 ± 11%, age 69 ± 5) and healthy controls (Healthy, n = 58, FEV1predicted 112 ± 16%, age 67 ± 4) conducted identical whole-body resistance training interventions for 13 weeks, consisting of two weekly supervised training sessions. Leg exercises were performed unilaterally, with one leg conducting high-load training (10RM) and the contralateral leg conducting low-load training (30RM). Measurements included muscle strength (nvariables = 7), endurance performance (nvariables = 6), muscle mass (nvariables = 3), muscle quality, muscle biology (m. vastus lateralis; muscle fiber characteristics, RNA content including transcriptome) and health variables (body composition, blood). For core outcome domains, weighted combined factors were calculated from the range of singular assessments. Results: COPD displayed well-known pathophysiologies at baseline, including elevated levels of systemic low-grade inflammation ([c-reactive protein]serum), reduced muscle mass and functionality, and muscle biological aberrancies. Despite this, resistance training led to improved lower-limb muscle strength (15 ± 8%), muscle mass (7 ± 5%), muscle quality (8 ± 8%) and lower-limb/whole-body endurance performance (26 ± 12%/8 ± 9%) in COPD, resembling or exceeding responses in Healthy, measured in both relative and numeric change terms. Within the COPD cluster, lower FEV1predicted was associated with larger numeric and relative increases in muscle mass and superior relative improvements in maximal muscle strength. This was accompanied by similar changes in hallmarks of muscle biology such as rRNA-content↑, muscle fiber cross-sectional area↑, type IIX proportions↓, and changes in mRNA transcriptomics. Neither of the core outcome domains were differentially affected by resistance training load. Conclusions: COPD showed hitherto largely unrecognized responsiveness to resistance training, rejecting the notion of disease-related impairments and rather advocating such training as a potent measure to relieve pathophysiologies. Trial registration: ClinicalTrials.gov ID: NCT02598830. Registered November 6th 2015, https://clinicaltrials.gov/ct2/show/NCT02598830. Keywords: Anabolic resistance; COPD; Pathophysiology; Skeletal muscle; Strength training; Training load.

• Mølmen, Knut Sindre; Jovanovic, Maja; Berg, Geir Vegard; Ellefsen, Stian & Grindaker, Eirik (2021). A qualitative analysis of motivational factors for resistance training in chronic obstructive pulmonary disease: experiences from The Granheim COPD Study. Fysioterapeuten. ISSN 0016-3384. Full text in Research Archive Show summary

  Bakgrunn: Regelmessig styrketrening gir gunstige helseeffekter for personer med kronisk obstruktiv lungesykdom (KOLS), og er derfor en naturlig del av lungerehabiliteringen. Pasienters opplevelse av slik trening er imidlertid lite studert. Hensikten med denne kvalitative studien var å kartlegge erfaringer med styrketrening hos deltakere i The Granheim COPD Study. Materiale og metode: Åtte av 24 prosjektdeltakere med KOLS (kvinner/menn, n=3/n=5; KOLS grad II/III, n=4/n=4; alder, 64-79 år) gjennomførte semistrukturerte, kvalitative intervjuer i den femte av totalt 13 uker med styrketrening. Funn: Samlet for alle prosjektdeltakerne med KOLS var treningsadherensen høy (97%) og frafallet lavt (n=2 av 22) under treningsperioden. Informantene som gjennomførte kvalitative intervjuer opplevde nokså høy og stigende grad av motivasjon for å trene under intervensjonen. Dette var knyttet til tett personlig oppfølging fra treningskyndig personell og opplevelse av trygghet under treningsøktene, samt økt mestringsfølelse og økt kompetanse. Fortolkning: Personlig veiledning fra treningskyndig personell var en avgjørende faktor for å øke treningsmotivasjonen blant studiedeltakerne. Individuell tilrettelegging og oppfølging ser derfor ut til å være en forutsetning for å oppnå gode aktivitetsvaner hos personer med KOLS. Nøkkelord: atferdsendring, kvalitativ forskning, lungerehabilitering, personlig treningsveiledning, treningsmotivasjon.

• Mølmen, Knut Sindre; Hammarström, Jens Konrad Daniel; Pedersen, Karianne; Lie, Anne Cecilie Lian; Steile, Ragnvald B. & Nygård, Håvard [Show all 18 contributors for this article] (2021). Vitamin D3 supplementation does not enhance the effects of resistance training in older adults . Journal of Cachexia, Sarcopenia and Muscle. ISSN 2190-5991. 12(3), p. 599–628. doi: 10.1002/jcsm.12688. Full text in Research Archive Show summary

  Background: Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored. Methods: Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments. Results: Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study. Conclusions: Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD. Keywords: Cholecalciferol; Muscle plasticity; Strength training. © 2021 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.

• Almquist, Nicki Winfield; Ellefsen, Stian; Sandbakk, Øyvind & Rønnestad, Bent (2020). Effects of including sprints during prolonged cycling on hormonal and muscular responses and recovery in elite cyclists. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. p. 1–13. doi: 10.1111/sms.13865. Full text in Research Archive Show summary

  This study investigated the acute effects of including 30‐second sprints during prolonged low‐intensity cycling on muscular and hormonal responses and recovery in elite cyclists. Twelve male cyclists (VO2max, 73.4 ± 4.0 mL/kg/min) completed a randomized crossover protocol, wherein 4 hours of cycling at 50% of VO2max were performed with and without inclusion of three sets of 3 × 30 seconds maximal sprints (E&S vs E, work‐matched). Muscle biopsies (m. vastus lateralis) and blood were sampled at Pre, immediately after (Post) and 3 hours after (3 h) finalizing sessions. E&S led to greater increases in mRNA levels compared with E for markers of fat metabolism (PDK4, Δ‐Log2 fold change between E&S and E ± 95%CI Post; 2.1 ± 0.9, Δ3h; 1.3 ± 0.7) and angiogenesis (VEGFA, Δ3h; 0.3 ± 0.3), and greater changes in markers of muscle protein turnover (myostatin, ΔPost; −1.4 ± 1.2, Δ3h; −1.3 ± 1.3; MuRF1, ΔPost; 1.5 ± 1.2, all P < .05). E&S showed decreased mRNA levels for markers of ion transport at 3h (Na+‐K+ α1; −0.6 ± 0.6, CLC1; −1.0 ± 0.8 and NHE1; −0.3 ± 0.2, all P < .05) and blunted responses for a marker of mitochondrial biogenesis (PGC‐1α, Post; −0.3 ± 0.3, 3h; −0.4 ± 0.3, P < .05) compared with E E&S and E showed similar endocrine responses, with exceptions of GH and SHBG, where E&S displayed lower responses at Post (GH; −4.1 ± 3.2 μg/L, SHBG; −2.2 ± 1.9 nmol/L, P < .05). Both E&S and E demonstrated complete recovery in isokinetic knee extension torque 24 hours after exercise. In conclusion, we demonstrate E&S to be an effective exercise protocol for elite cyclists, which potentially leads to beneficial adaptations in skeletal muscle without impairing muscle recovery 24 hours after exercise.

• Khan, Yusuf; Hammarström, Jens Konrad Daniel; Rønnestad, Bent; Ellefsen, Stian & Ahmad, Rafi (2020). Increased biological relevance of transcriptome analyses in human skeletal muscle using a model-specific pipeline. BMC Bioinformatics. ISSN 1471-2105. 21(1). doi: 10.1186/s12859-020-03866-y. Full text in Research Archive Show summary

  Background: Human skeletal muscle responds to weight-bearing exercise with significant inter-individual differences. Investigation of transcriptome responses could improve our understanding of this variation. However, this requires bioinformatic pipelines to be established and evaluated in study-specific contexts. Skeletal muscle subjected to mechanical stress, such as through resistance training (RT), accumulates RNA due to increased ribosomal biogenesis. When a fixed amount of total-RNA is used for RNA-seq library preparations, mRNA counts are thus assessed in different amounts of tissue, potentially invalidating subsequent conclusions. The purpose of this study was to establish a bioinformatic pipeline specific for analysis of RNA-seq data from skeletal muscles, to explore the effects of different normalization strategies and to identify genes responding to RT in a volume-dependent manner (moderate vs. low volume). To this end, we analyzed RNA-seq data derived from a twelve-week RT intervention, wherein 25 participants performed both low- and moderate-volume leg RT, allocated to the two legs in a randomized manner. Bilateral muscle biopsies were sampled from m. vastus lateralis before and after the intervention, as well as before and after the fifth training session (Week 2). Result: Bioinformatic tools were selected based on read quality, observed gene counts, methodological variation between paired observations, and correlations between mRNA abundance and protein expression of myosin heavy chain family proteins. Different normalization strategies were compared to account for global changes in RNA to tissue ratio. After accounting for the amounts of muscle tissue used in library preparation, global mRNA expression increased by 43-53%. At Week 2, this was accompanied by dose-dependent increases for 21 genes in rested-state muscle, most of which were related to the extracellular matrix. In contrast, at Week 12, no readily explainable dose-dependencies were observed. Instead, traditional normalization and non-normalized models resulted in counterintuitive reverse dose-dependency for many genes. Overall, training led to robust transcriptome changes, with the number of differentially expressed genes ranging from 603 to 5110, varying with time point and normalization strategy. Conclusion: Optimized selection of bioinformatic tools increases the biological relevance of transcriptome analyses from resistance-trained skeletal muscle. Moreover, normalization procedures need to account for global changes in rRNA and mRNA abundance. Keywords: Bioinformatics pipeline; Normalization; RNA-seq; Skeletal muscle.

• Støa, Eva Maria; Helgerud, Jan; Rønnestad, Bent; Hansen, Joar; Ellefsen, Stian & Støren, Øyvind (2020). Factors Influencing Running Velocity at Lactate Threshold in Male and Female Runners at Different Levels of Performance. Frontiers in Physiology. ISSN 1664-042X. 11, p. 1–8. doi: 10.3389/fphys.2020.585267. Full text in Research Archive
• Vikmoen, Olav; Raastad, Truls; Ellefsen, Stian & Rønnestad, Bent (2020). Adaptations to strength training differ between endurance-trained and untrained women. European Journal of Applied Physiology. ISSN 1439-6319. 120(7), p. 1541–1549. doi: 10.1007/s00421-020-04381-x. Full text in Research Archive Show summary

  Purpose: The purpose of this study was to investigate if endurance athletes, sustaining their normal endurance training, experience attenuated adaptations to strength training compared to untrained individuals. Methods: Eleven non-strength-trained female endurance athletes (E + S) added 11 weeks of strength training to their normal endurance training (5.1 ± 1.1 h per week), and 10 untrained women (S) performed the same strength training without any endurance training. The strength training consisted of four leg exercises [3 × 4 − 10 repetition maximum (RM)], performed twice a week for 11 weeks. Results: E + S and S displayed similar increases in 1RM one-legged leg press (E + S 39 ± 19%, S 42 ± 17%, p < 0.05), maximal isometric torque in knee extension (E + S 12 ± 11%, S 8 ± 10%, p < 0.05) and lean mass in the legs (E + S 3 ± 4%, S 3 ± 3%, p < 0.05). However, S displayed superior increases in peak torque in knee extension at an angular velocity of 240° sec−1 (E + S 8 ± 5%, S 15 ± 7%, p < 0.05) and maximal squat jump height (E + S 8 ± 6%, S 14 ± 7%, p < 0.05). Conclusions: In this study, concurrent training did not impair the adaptations in the ability to develop force at low contraction velocities or muscle hypertrophy. However, concurrent training attenuated strength training-associated changes in the ability to develop force at higher muscular contraction velocities.

• Almquist, Nicki Winfield; Nygård, Håvard; Vegge, Geir; Hammarström, Jens Konrad Daniel; Ellefsen, Stian & Rønnestad, Bent (2020). Systemic and muscular responses to effort-matched short intervals and long intervals in elite cyclists. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30, p. 1140–1150. doi: 10.1111/sms.13672. Full text in Research Archive Show summary

  The purpose of this study was to compare the acute effects of time- and effort-matched high-intensity intervals on physiological, endocrine, and skeletal muscle molecular variables in elite cyclists. Eight elite cyclists performed short intervals (SI: 30-seconds) and long intervals (LI: 5-minutes) with work:recovery ratio 2:1, using a randomized crossover design. SI was associated with 14% ± 3% higher mean power output (SI; 421 ± 27 vs LI; 371 ± 22 W), and longer working time above 90% of maximal oxygen uptake (VO2max, 54% ± 76%) and 90% peak heart rate (HRpeak, 153% ± 148%) than LI (all P < .05), despite similar degrees of perceived exertion, blood lactate levels and muscle activation measured using EMG root mean square (EMG rms). In blood, SI was associated with more pronounced increases in testosterone and testosterone-tosex hormone-binding globulin (SHBG) ratios, as well as prolonged cortisol responses (P < .05). In skeletal muscle (m. Vastus lateralis), SI and LI led to similar changes in mRNA abundance for a range of transcripts, with the exception of NHE1 mRNA, which decreased after SI (P < .05). Overall, SI was associated with more pronounced physiological and endocrine responses than LI in elite cyclists, suggesting that such training might lead to superior adaptations in elite cyclists.

• Øfsteng, Sjur Johansen; Garthe, Ina; Jøsok, Øyvind; Knox, Silje; Helkala, Kirsi Marjaana & Knox, Benjamin James [Show all 8 contributors for this article] (2020). No effect of increasing protein intake during military exercise with severe energy deficit on body composition and performance. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30(5), p. 865–877. doi: 10.1111/sms.13634. Show summary

  In this study, we compare the effects of isocaloric high- (HIGH: 2 g kg−1d−1, n = 19) and low-protein diet (LOW: 1 g kg−1d−1, n = 19) on changes in body composition, muscle strength, and endocrine variables in response to a 10-day military field exercise with energy deficit, followed by 7 days of recovery. Body composition (DXA), one repetition maximum (1RM) bench and leg press, counter-movement jump height (CMJ) and blood variables were assessed before and after the exercise. Performance and blood variables were reassessed after 7days of recov-ery. The 10-day exercise resulted in severe energy deficit in both LOW and HIGH (−4373±1250, −4271±1075kcald−1) and led to decreased body mass (−6.1%, −5.2%), fat mass (−40.5%, −33.4%), 1RM bench press (−9.5%, −9.7%), 1RM leg press (−7.8%, −8.3%), and CMJ (−14.7%, −14.6%), with no differences between groups. No change was seen for fat-free mass. In both groups, the exercise led to a switch toward a catabolic physiological milieu, evident as reduced levels of anabolic hormones (testosterone, IGF-1) and increased levels of cortisol (more pronounced in HIGH, P<.05). Both groups also displayed substantial increases in creatine kinase. After 7days of recovery, most variables had returned to close-to pre-exercise levels, except for CMJ, which remained at reduced levels. In conclusion, increased protein intake during 10-day military field exercise with severe energy deficiency did not mitigate loss of body mass or impairment of physical performance.KEYWORDScortisol, energy deficiency, nutrient supplement, soldiers, strength, testosterone

• Hammarström, Daniel; Øfsteng, Sjur Johansen; Koll, Lise; Hanestadhaugen, Marita; Hollan, Ivana & Apro, William [Show all 10 contributors for this article] (2019). Benefits of higher resistance‐training volume are related to ribosome biogenesis. Journal of Physiology. ISSN 0022-3751. 598(3), p. 543–565. doi: 10.1113/JP278455. Full text in Research Archive Show summary

  Abstract Resistance-exercise volume is a determinant of training outcomes. However not all individuals respond in a dose-dependent fashion. In this study, 34 healthy individuals (males n = 16, 23.6 (4.1) years; females n = 18, 22.0 (1.3) years) performed moderate- (3 sets per exercise, MOD) and low-volume (1 set, LOW) resistance training in a contralateral fashion for 12 weeks (2–3 sessions per week). Muscle cross-sectional area (CSA) and strength were assessed at Weeks 0 and 12, along with biopsy sampling (m. vastus lateralis). Muscle biopsies were alsosampled before and 1 h after the fifth session (Week 2). MOD resulted in larger increases in muscleCSA (5.2 (3.8)% versus 3.7 (3.7)%, P < 0.001) and strength (3.4–7.7% difference, all P < 0.05.This coincided with greater reductions in type IIX fibres from Week 0 to Week 12 (MOD,−4.6 percentage p oints; LOW −3.2 percentage points), greater phosphorylation of S6-kinase 1(p85 S6K1Thr412, 19%; p70 S6K1Thr389, 58%) and ribosomal protein S6Ser235/236(37%), greaterrested-state total RNA (8.8%) and greater exercise-induced c-Myc mRNA expression (25%;Week 2, all P < 0.05). Thirteen and sixteen participants, respectively, displayed clear benefits inresponse to MOD on muscle hypertrophy and strength. Benefits were associated with greateraccumulation of total RNA at Week 2 in the MOD leg, with every 1% difference increasing theodds of MOD benefit by 7.0% (P = 0.005) and 9.8% (P = 0.002). In conclusion, MOD led togreater functional and biological adaptations than LOW. Associations between dose-dependenttotal RNA accumulation and increases in muscle mass and strength point to ribosome biogenesisas a determinant of dose-dependent training responses.

• Mølmen, Knut Sindre; Thy, Jonas Evensen; Dalane, Stine Thallaug; Ellefsen, Stian & Falch, Gunnar Slettaløkken (2019). Muscular performance decreases with increasing complexity of resistance exercises in subjects with chronic obstructive pulmonary disease. Translational Sports Medicine (TSM). ISSN 2573-8488. 3(1), p. 26–33. doi: 10.1002/tsm2.118. Full text in Research Archive
• Couturier, Christine Stephanie; Stecyk, Jonathan Anthony William; Ellefsen, Stian; Sandvik, Guro Katrine; Milton, Sarah L. & Prentice, Howard M. [Show all 7 contributors for this article] (2019). The expression of genes involved in excitatory and inhibitory neurotransmission in turtle (Trachemys scripta) brain during anoxic submergence at 21°C and 5°C reveals the importance of cold as a preparatory cue for anoxia survival. Comparative Biochemistry and Physiology - Part D:Genomics and Proteomics. ISSN 1744-117X. 30, p. 55–70. doi: 10.1016/j.cbd.2018.12.010. Full text in Research Archive
• Ellefsen, Stian & Baar, Keith (2018). Proposed Mechanisms Underlying the Interference Effect: Scientific Basics and Practical Applications. In Schumann, Moritz & Rønnestad, Bent (Ed.), Concurrent Aerobic and Strength Training. Springer Nature. ISSN 978-3-319-75546-5. p. 89–97. doi: 10.1007/978-3-319-75547-2_7.
• Rønnestad, Bent; Øfsteng, Sjur Johansen & Ellefsen, Stian (2018). Block periodization of strength and endurance training is superior to traditional periodization in ice hockey players. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. p. 1–9. doi: 10.1111/sms.13326.
• Hughes, David C.; Ellefsen, Stian & Baar, Keith (2018). Adaptations to endurance and strength training. Cold Spring Harbor Perspectives in Medicine. ISSN 2157-1422. 8(6). doi: 10.1101/cshperspect.a029769. Show summary

  The capacity for human exercise performance can be enhanced with prolonged exercise training, whether it is endurance- or strength-based. The ability to adapt through exercise training allows individuals to perform at the height of their sporting event and/or maintain peak physical condition throughout the life span. Our continued drive to understand how to prescribe exercise to maximize health and/or performance outcomes means that our knowledge of the adaptations that occur as a result of exercise continues to evolve. This review will focus on current and new insights into endurance and strength-training adaptations and will highlight important questions that remain as far as how we adapt to training.

• Fagernes, Cathrine Elisabeth; Stensløkken, Kåre-Olav; Kjendseth, Åsmund Røhr; Berenbrink, Michael; Ellefsen, Stian & Nilsson, Göran Erik (2017). Extreme anoxia tolerance in crucian carp and goldfish through neofunctionalization of duplicated genes creating a new ethanol- producing pyruvate decarboxylase pathway. Scientific Reports. ISSN 2045-2322. doi: 10.1038/s41598-017-07385-4. Full text in Research Archive
• Vikmoen, Olav; Rønnestad, Bent; Ellefsen, Stian & Raastad, Truls (2017). Heavy strength training improves running and cycling performance following prolonged submaximal work in well-trained female athletes. Physiological Reports. ISSN 2051-817X. 5. doi: 10.14814/phy2.13149. Show summary

  The purpose of this study was to investigate the effects of adding heavy strength training to female duathletes' normal endurance training on both cycling and running performance. Nineteen well‐trained female duathletes (VO2max cycling: 54 ± 3 ml∙kg−1∙min−1, VO2max running: 53 ± 3 ml∙kg−1∙min−1) were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four lower body exercises [3 × 4‐10 repetition maximum (RM)] twice a week for 11 weeks. Running and cycling performance were assessed using 5‐min all‐out tests, performed immediately after prolonged periods of submaximal work (3 h cycling or 1.5 h running). E+S increased 1RM in half squat (45 ± 22%) and lean mass in the legs (3.1 ± 4.0%) more than E. Performance during the 5‐min all‐out test increased in both cycling (7.0 ± 4.5%) and running (4.7 ± 6.0%) in E+S, whereas no changes occurred in E. The changes in running performance were different between groups. E+S reduced oxygen consumption and heart rate during the final 2 h of prolonged cycling, whereas no changes occurred in E. No changes occurred during the prolonged running in any group. Adding strength training to normal endurance training in well‐trained female duathletes improved both running and cycling performance when tested immediately after prolonged submaximal work.

• Nygård, Håvard; Slettaløkken, Gunnar; Whist, Jon Elling; Hollan, Ivana; Ellefsen, Stian & Holmboe-Ottesen, Gerd [Show all 8 contributors for this article] (2017). Acute effects of post-absorptive and postprandial moderate exercise on markers of inflammation in hyperglycemic individuals. European Journal of Applied Physiology. ISSN 1439-6319. 117(4), p. 1–8. doi: 10.1007/s00421-017-3576-2. Full text in Research Archive Show summary

  Abstract Purpose Systemic inflammation is involved in the development of several diseases, including cardiovascular disease and type 2 diabetes. It is known that vigorous exercise affects systemic inflammation, but less is known about exercise at lower intensities. Hyperglycemia can also entail pro-inflammatory responses; however, postprandial hyperglycemia is blunted if the meal is followed by exercise. Hypotheses were: (1) moderate physical exercise acutely affects levels of C-reactive protein (CRP) and serum soluble vascular cell adhesion molecule 1 (sVCAM-1) in hyperglycemic individuals and (2) the effect depends on whether the activity is performed in a post-absorptive or postprandial state. Methods Twelve participants diagnosed with hyperglycemia, but not using anti-diabetic medication, underwent three test days in a randomized cross-over study; 1 control day without exercise, 1 day with 60 min of treadmill walking ending 30 min before breakfast, and 1 day with an identical bout of activity 30 min after the start of breakfast. Food intake was strictly standardized and venous blood for CRP, and sVCAM-1 analysis was sampled at standardized timepoints during the first 3.5 h after breakfast and once 24 h later. Results Merged data from the two exercise days showed that sVCAM-1 increased from baseline (4 ± 16 ng/mL) compared to the control condition (−28 ± 47 ng/mL, ES = 0.7, p = 0.024). There was no statistically significant difference in changes in sVCAM-1 levels between the two exercise test days. Exercise did not affect CRP values. Conclusion Moderate exercise increases sVCAM-1 in hyperglycemic individuals, whereas it does not affect CRP.

• Rønnestad, Bent; Slettaløkken, Gunnar & Ellefsen, Stian (2016). The effect of whole-body vibration on subsequent sprint performance in well-trained cyclists. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 12(7), p. 964–968. doi: 10.1123/ijspp.2016-0428.
• Cumming, Kristoffer Toldnes; Ellefsen, Stian; Rønnestad, Bent; Ugelstad, Ingrid & Raastad, Truls (2016). Acute and long-term effects of blood flow restricted training on heat shock proteins and endogenous antioxidant systems. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 27(11), p. 1190–1201. doi: 10.1111/sms.12774. Show summary

  Blood flow restricted exercise (BFRE) with low loads has been demonstrated to induce considerable stress to exercising muscles. Muscle cells have developed a series of defensive systems against exercise-induced stress. However, little is known about acute and long-term effects of BFRE training on these systems. Nine previously untrained females trained low-load BFRE and heavy load strength training (HLS) on separate legs and on separate days to investigate acute and long-term effects on heat shock proteins (HSP) and endogenous antioxidant systems in skeletal muscles. BFRE and HLS increased muscle strength similarly by 12 ± 7% and 12 ± 6%, respectively, after 12 weeks of training. Acutely after the first BFRE and HLS exercise session, αB-crystallin and HSP27 content increased in cytoskeletal structures, accompanied by increased expression of several HSP genes. After 12 weeks of training, this acute HSP response was absent. Basal levels of αB-crystallin, HSP27, HSP70, mnSOD, or GPx1 remained unchanged after 12 weeks of training, but HSP27 levels increased in the cytoskeleton. Marked translocation of HSP to cytoskeletal structures at the commencement of training indicates that these structures are highly stressed from BFRE and HLS. However, as the muscle gets used to this type of exercise, this response is abolished.

• Eftestøl, Einar; Egner, Ingrid Marie; Lunde, Ida Gjervold; Ellefsen, Stian; Andersen, Tom & Sjåland, Cecilie [Show all 8 contributors for this article] (2016). Increased hypertrophic response with increased mechanical load in skeletal muscles receiving identical activity patterns. American Journal of Physiology - Cell Physiology. ISSN 0363-6143. 311(4), p. C616–C629. doi: 10.1152/ajpcell.00016.2016.
• Vikmoen, Olav; Raastad, Truls; Seynnes, Olivier R.; Bergstrøm, Kristoffer; Ellefsen, Stian & Rønnestad, Bent (2016). Effects of Heavy Strength Training on Running Performance and Determinants of Running Performance in Female Endurance Athletes. PLOS ONE. ISSN 1932-6203. 11(3). doi: 10.1371/journal.pone.0150799.
• Vikmoen, Olav; Ellefsen, Stian; Trøen, Øyvind; Hollan, Ivana; Hanestadhaugen, Marita & Raastad, Truls [Show all 7 contributors for this article] (2016). Strength training improves cycling performance, fractional utilization of VO2max and cycling economy in female cyclists. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 26(4), p. 384–396. doi: 10.1111/sms.12468. Show summary

  The purpose of this study was to investigate the effect of adding heavy strength training to well-trained female cyclists’ normal endurance training on cycling performance. Nineteen female cyclists were randomly assigned to 11 weeks of either normal endurance training combined with heavy strength training (E+S, n = 11) or to normal endurance training only (E, n = 8). E+S increased one repetition maximum in one-legged leg press and quadriceps muscle cross-sectional area (CSA) more than E (P < 0.05), and improved mean power output in a 40-min all-out trial, fractional utilization of VO2max and cycling economy (P < 0.05). The proportion of type IIAX-IIX muscle fibers in m. vastus lateralis was reduced in E+S with a concomitant increase in type IIA fibers (P < 0.05). No changes occurred in E. The individual changes in performance during the 40-min all-out trial was correlated with both change in IIAX-IIX fiber proportion (r = −0.63) and change in muscle CSA (r = 0.73). In conclusion, adding heavy strength training improved cycling performance, increased fractional utilization of VO2max, and improved cycling economy. The main mechanisms behind these improvements seemed to be increased quadriceps muscle CSA and fiber type shifts from type IIAX-IIX toward type IIA

• Rønnestad, Bent; Slettaløkken, Gunnar & Ellefsen, Stian (2016). Adding Whole Body Vibration to Preconditioning Exercise Increases Subsequent On-Ice Sprint Performance in Ice-hockey Players. Journal of Strength and Conditioning Research. ISSN 1064-8011. 30(4), p. 1021–1026. doi: 10.1097/JSC.0000000000000210. Show summary

  AB The phenomenon postactivation potentiation can possibly be used to acutely improve sprint performance. The purpose of this study was to investigate the effect of body-loaded half-squats with added whole body vibration (WBV) on subsequent 20 m on-ice sprint performance. Fifteen male ice-hockey players performed four test sessions on separate days and in a randomized order. Two of this test sessions were with WBV and two were with no WBV and the best sprint time was used to determine effectiveness. Each test session included preconditioning 30 s half-squat exercise, two of which were supplemented with 50 Hz WBV at a amplitude of 3 mm. One minute after the cessation of the preconditioning exercise, the 20 m sprint test was performed. Intermediate time was sampled after 10 m. Preconditioning exercise performed with 50 Hz WBV resulted in superior 10 m and 20 m sprint performance compared to preconditioning exercise performed without WBV (1.84 +/- 0.10 s vs. 1.89 +/- 0.10 s and 3.14 +/- 0.13 vs. 3.17 +/- 0.13 s, respectively, p <= 0.01). There was no difference between the protocols in perceived well-being of the legs before the warm-up or after the warm up (p = 0.3). However, there was an improved well-being in the legs immediately after the preconditioning exercise with WBV (p < 0.05). In conclusion, preconditioning exercise performed with WBV at 50 Hz seems to enhance on-ice sprint performance in ice-hockey players. This suggests that coaches can incorporate such exercise into the preparation to specific sprint training to improve the quality of the training. Copyright (C) 2014 by the National Strength & Conditioning Association.

• Rønnestad, Bent; Hansen, Joar; Hollan, Ivana; Spencer, Matthew & Ellefsen, Stian (2015). In-Season Strength Training Cessation Impairs Performance Variables in Elite Cyclists. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. doi: 10.1123/ijspp.2015-0372. Show summary

  The present study investigates the effects of 8 weeks of strength training cessation following 25 weeks of strength training on strength- and cycling performance characteristics. Elite cyclists were randomly assigned to either 25 weeks of endurance training combined with heavy strength training [EXP, n=7, maximal oxygen uptake (VO2max): 77±6 ml·kg-1·min-1 (3x4-10 RM, 1-2 day·week-1)] or to endurance training only [CON, n=7, VO2max: 73±5 ml·kg-1·min-1]. Thereafter, both groups performed endurance training only for 8 weeks, coinciding with the initial part of the competition season. Data were assessed for practical significance using magnitude-based inferences. During the 25-week preparatory period, EXP had a larger positive impact on maximal isometric half squat force, squat jump (SJ), maximal aerobic power (Wmax), power output at 4 mmol∙L-1 [la-], and mean power in 30-s Wingate test compared to CON (ES=0.46-0.74). Conversely, during the 8-week competition period EXP had a reduction in SJ, Wmax, and mean power in the 30-s Wingate test compared to CON (ES=0.49-0.84). The present findings suggest rapid decline of adaptations upon termination of strength training during the 8 first weeks of the competition period in elite cyclists.

• Ellefsen, Stian; Hammarström, Daniel; Strand, Tor; Zacharoff, Erika; Whist, Jon Elling & Rauk, Irene [Show all 14 contributors for this article] (2015). Blood flow-restricted strength training displays high functional and biological efficacy in women: a within-subject comparison with high-load strength training. American Journal of Physiology. Regulatory Integrative and Comparative Physiology. ISSN 0363-6119. 309(7), p. R767–R779. doi: 10.1152/ajpregu.00497.2014. Show summary

  Limited data exist on the efficacy of low-load blood flow-restricted strength training (BFR), as compared directly to heavy-load strength training (HST). Here, we show that 12 wk of twice-a-week unilateral BFR [30% of one repetition maximum (1RM) to exhaustion] and HST (6-10RM) of knee extensors provide similar increases in 1RM knee extension and cross-sectional area of distal parts of musculus quadriceps femoris in nine untrained women (age 22 ± 1 yr). The two protocols resulted in similar acute increases in serum levels of human growth hormone. On the cellular level, 12 wk of BFR and HST resulted in similar shifts in muscle fiber composition in musculus vastus lateralis, evident as increased MyHC2A proportions and decreased MyHC2X proportions. They also resulted in similar changes of the expression of 29 genes involved in skeletal muscle function, measured both in a rested state following 12 wk of training and subsequent to singular training sessions. Training had no effect on myonuclei proportions. Of particular interest, 1) gross adaptations to BFR and HST were greater in individuals with higher proportions of type 2 fibers, 2) both BFR and HST resulted in approximately four-fold increases in the expression of the novel exercise-responsive gene Syndecan-4, and 3) BFR provided lesser hypertrophy than HST in the proximal half of musculus quadriceps femoris and also in CSApeak, potentially being a consequence of pressure from the tourniquet utilized to achieve blood flow restriction. In conclusion, BFR and HST of knee extensors resulted in similar adaptations in functional, physiological, and cell biological parameters in untrained women.

• Nygård, Håvard; Slettaløkken, Gunnar; Vegge, Geir; Hollan, Ivana; Whist, Jon Elling & Strand, Tor [Show all 8 contributors for this article] (2015). Irisin in Blood Increases Transiently after Single Sessions of Intense Endurance Exercise and Heavy Strength Training. PLOS ONE. ISSN 1932-6203. 10(3). doi: 10.1371/journal.pone.0121367. Show summary

  Purpose Irisin is a recently identified exercise-induced hormone that increases energy expenditure, at least in rodents. The main purpose of this study was to test the hypothesis that Irisin increases acutely in blood after singular sessions of intense endurance exercise (END) and heavy strength training (STR). Secondary, we wanted to explore the relationship between body composition and exercise-induced effects on irisin, and the effect of END and STR on muscular expression of the irisin gene FNDC5. Methods Nine moderately trained healthy subjects performed three test days using a randomized and standardized crossover design: one day with 60 minutes of END, one day with 60 minutes of STR, and one day without exercise (CON). Venous blood was sampled over a period of 24h on the exercise days. Results Both END and STR led to transient increases in irisin concentrations in blood, peaking immediately after END and one hour after STR, before gradually returning to baseline. Irisin responses to STR, but not END, showed a consistently strong negative correlation with proportions of lean body mass. Neither END nor STR affected expression of FNDC5, measured 4h after training sessions, though both protocols led to pronounced increases in PGC-1α expression, which is involved in transcriptional control of FNDC5. Conclusion The results strongly suggest that single sessions of intense endurance exercise and heavy strength training lead to transient increases in irisin concentrations in blood. This was not accompanied by increased FNDC5 expression, measured 4h post-exercise. The results suggest that irisin responses to resistance exercise are higher in individuals with lower proportions of lean body mass.

• Rønnestad, Bent; Hansen, Joar; Hollan, Ivana & Ellefsen, Stian (2015). Strength training improves performance and pedaling characteristics in elite cyclists. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 25(1), p. e89–e98. doi: 10.1111/sms.12257.
• Rønnestad, Bent; Ellefsen, Stian; Nygård, Håvard; Zacharoff, Erika; Vikmoen, Olav & Hansen, Joar [Show all 7 contributors for this article] (2014). Effects of 12 weeks of block periodization on performance and performance indices in well-trained cyclists. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 24(2), p. 327–335. doi: 10.1111/sms.12016.
• Rønnestad, Bent; Hansen, Joar & Ellefsen, Stian (2014). Block periodization of high-intensity aerobic intervals provides superior training effects in trained cyclists. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 24(1), p. 34–42. doi: 10.1111/j.1600-0838.2012.01485.x.
• Stensløkken, Kåre-Olav; Ellefsen, Stian; Vasieva, Olga; Fang, Youhan; Farrell, Anthony P. & Olohan, Lisa [Show all 9 contributors for this article] (2014). Life without Oxygen: Gene Regulatory Responses of the Crucian Carp (Carassius carassius) Heart Subjected to Chronic Anoxia. PLOS ONE. ISSN 1932-6203. 9(11). doi: 10.1371/journal.pone.0109978. Full text in Research Archive
• Ellefsen, Stian; Vikmoen, Olav; Zacharoff, Erika; Rauk, Irene; Slettaløkken, Gunnar & Hammarström, Daniel [Show all 14 contributors for this article] (2014). Reliable determination of training-induced alterations in muscle fiber composition in human skeletal muscle using quantitative polymerase chain reaction. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 24(4), p. e332–e342. doi: 10.1111/sms.12185. Show summary

  Determination of muscle fiber composition in human skeletal muscle biopsies is often performed using immunohistochemistry, a method that tends to be both time consuming, technically challenging, and complicated by limited availability of tissue. Here, we introduce quantitative reverse transcriptase polymerase chain reaction (qRT-PCR)-based Gene-family profiling (GeneFam) of myosin heavy chain (MyHC) mRNA expression as a high-throughput, sensitive, and reliable alternative. We show that GeneFam and immunohistochemistry result in similar disclosures of alterations in muscle fiber composition in biopsies from musculus vastus lateralis and musculus biceps brachii of previously untrained young women after 12 weeks of progressive strength training. The adaptations were evident as (a) consistent increases in MyHC2A abundance; (b) consistent decreases in MyHC2X abundance; and (c) consistently stable MyHC1 abundance, and were not found using traditional reference gene-based qRT-PCR analyses. Furthermore, muscle fiber composition found using each of the two approaches was correlated with each other (r = 0.50, 0.74, and 0.78 for MyHC1, A, and X, respectively), suggesting that GeneFam may be suitable for ranking of individual muscle phenotype, particularly for MyHC2 fibers. In summary, GeneFam of MyHC mRNA resulted in reliable assessment of alterations in muscle fiber composition in skeletal muscle of previously untrained women after 12 weeks of strength training.

• Ellefsen, Stian; Vikmoen, Olav; Slettaløkken, Gunnar; Whist, Jon Elling; Nygård, Håvard & Hollan, Ivana [Show all 11 contributors for this article] (2014). Irisin and FNDC5: effects of 12-week strength training, and relations to muscle phenotype and body mass composition in untrained women. European Journal of Applied Physiology. ISSN 1439-6319. 114(9), p. 1875–1888. doi: 10.1007/s00421-014-2922-x. Show summary

  Purpose: To investigate the effects of strength training on abundances of irisin-related biomarkers in skeletal muscle and blood of untrained young women, and their associations with body mass composition, muscle phenotype and levels of thyroid hormones. Methods: Eighteen untrained women performed 12 weeks of progressive whole-body heavy strength training, with measurement of strength, body composition, expression of irisin-related genes (FNDC5 and PGC1α) in two different skeletal muscles, and levels of serum-irisin and -thyroid hormones, before and after the training intervention. Results: The strength training intervention did not result in changes in serum-irisin or muscle FNDC5 expression, despite considerable effects on strength, lean body mass (LBM) and skeletal muscle phenotype. Our data indicate that training affects irisin biology in a LBM-dependent manner. However, no association was found between steady-state serum-irisin or training-associated changes in serum-irisin and alterations in body composition. FNDC5 expression was higher in m.Biceps brachii than in m.Vastus lateralis, with individual expression levels being closely correlated, suggesting a systemic mode of transcriptional regulation. In pre-biopsies, FNDC5 expression was correlated with proportions of aerobic muscle fibers, a relationship that disappeared in post-biopsies. No association was found between serum-thyroid hormones and FNDC5 expression or serum-irisin. Conclusion: No evidence was found for an effect of strength training on irisin biology in untrained women, though indications were found for a complex interrelationship between irisin, body mass composition and muscle phenotype. FNDC5 expression was closely associated with muscle fiber composition in untrained muscle.

• Støren, Øyvind; Rønnestad, Bent; Sunde, Arnstein; Hansen, Joar; Ellefsen, Stian & Helgerud, Jan (2014). A time-saving method to assess power output at lactate threshold in well-trained and elite cyclists. Journal of Strength and Conditioning Research. ISSN 1064-8011. 28(3), p. 622–629. doi: 10.1519/JSC.0b013e3182a73e70.

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• Odden, Ingvill; Hamarsland, Håvard & Ellefsen, Stian (2024). Fyller fryseren med vev, blod og avføring: Det gir Solbjørg et nytt liv . [Newspaper]. Gudbrandsdølen Dagningen (GD).
• Ellefsen, Stian (2023). Er trening medisin?
• Ellefsen, Stian; Hammarström, Daniel; Mølmen, Knut Sindre & Hamarsland, Håvard (2022). The Trainome – combining exercise training and nutrition to improve the health efficacy of lifestyle therapy.
• Grindaker, Eirik; Nygård, Håvard; Ellefsen, Stian; Hamarsland, Håvard & Mølmen, Knut Sindre (2022). Podkasten "Trening": Organkonkurransen (10 episoder). [Radio]. Spotify. Show summary

  Fagpersoner fra Seksjon for Helse og Treningsfysiologi, Høgskolen i Innlandet, tar en gjennomgang av kroppens organer og diskuterer hvilke effekter fysisk aktivitet/trening har på det spesifikke organet, og hvilke responser ulike treningstyper gir. I tillegg diskuterer vi hvor avgjørende fysisk aktivitet/trening er for god organisk funksjon, og hvilken betydning organet har for effekten av trening generelt.

• Hamarsland, Håvard; Hammarström, Jens Konrad Daniel; Hafsmo, Mads-Henrik; Varpestuen, Tomas & Ellefsen, Stian (2022). Evidence for volume-dependent cross-learning during 10 weeks of unilateral heavy resistance training. Show summary

  INTRODUCTION: Unilateral training protocols allow one individual to undergo two different treatments within the same timeframe, allocated to each of the two limbs. The benefit of such designs includes increased statistical power, due to within-individual comparisons, with accompanying reductions in required resources. Despite this, training interventions seldom employ unilateral designs, which is likely due to potential cross-learning effects between the two limbs, whereby training of one limb induces gains in strength in the contralateral limb, as reported in a number of studies. Although the presence of such cross-learning effects is widely accepted, it has proven difficult to conclude on this perspective, due to several methodological issues with previous studies. The goal of the current study was to investigate the potential cross-learning effects during a 10-week unilateral training intervention with two different training volumes or lack thereof. METHODS: Healthy untrained subjects (♂:12, ♀:27, 24.4±3.9 yrs) participated in a 10-week whole-body training intervention, wherein the legs were exposed to either of three interventions, i) no training, ii) three sets of 10RM resistance training (RT), or iii) six sets of 10RM RT, performed three times per week in a contralateral manner (leg press and knee extension). For these interventions, participants performed either of five combinations: 0-3, 0-6, 3-6, 0-0 and 3-3. Muscle strength was assessed as 1RM (leg press and knee extension) and isokinetic strength (0°/sec, 60°/sec and 240°/sec), performed 4 times during the initial 3 weeks of training and 2 times in week 11. Average weighted mean changes after familiarization were used in analyses. Muscle mass was assessed as mid-thigh muscle thickness (m. vastus lateralis and m. vastus intermedius, ultrasound) in weeks 1, 3, 7 and 11. Group * Time effects were evaluated using mixed-effects models. RESULTS: Strength development in non-trained legs showed an interaction effect with the training volume performed by the other leg (group * time P=0.011), increasing 6.9 % in 0-6 (95% CI: 1.7, 12.4) and 2.0 % in 0-3 [-2.8, 7.0] compared to 0-0. This was not seen in the 3-set leg (group * time P=0.110). For muscle thickness, neither non-trained legs nor three-set legs displayed contralateral spillover from the trained leg (non-trained legs, group * time P=0.728; three-set leg, group * time P=0.728). CONCLUSION: In contralateral training designs, cross-learning may affect strength outcome in non-training control limbs, but not muscle mass. The extent of the contralateral training effect seems to be influenced by the prescribed training volume in the trained limb.

• Ellefsen, Stian; Hausstätter, Rune & Stokland, Inger (2022). Uenige om flytting av høgskolen. [Newspaper]. Gudbrandsdølen Dagningen.
• Ellefsen, Stian & Hammarström, Jens Konrad Daniel (2021). Forskere har undersøkt myten om at tung trening gir størst fremgang. Forskersonen.no.
• Ellefsen, Stian & Mølmen, Knut Sindre (2021). The miracle cure is exercise, not vitamin D. sciencenorway.no.
• Ellefsen, Stian & Mølmen, Knut Sindre (2021). Mirakelkuren er trening, ikke vitamin D. Forskersonen.no.
• Khan, Yusuf; Hammarström, Jens Konrad Daniel; Ellefsen, Stian & Ahmad, Rafi (2019). RNA-seq pipeline and transcriptome response to resistance training.
• Khan, Yusuf; Hammarström, Jens Konrad Daniel; Ellefsen, Stian & Ahmad, Rafi (2019). RNA-seq pipeline and transcriptome response to resistance training.
• Ellefsen, Stian (2019). Å vokse med Regionale forskningsfond.
• Ellefsen, Stian & Hammarstrøm, Daniel (2019). Benefits of higher resistance-training volume depends on ribosome biogenesis.
• Ellefsen, Stian & Hamarsland, Håvard (2019). Treningseffekter og fedme. [Radio]. NRK P1.
• Ellefsen, Stian (2019). Trainome: om treningsresponser, arv og miljø og sånt.
• Stokland, Inger; Ellefsen, Stian & Hamarsland, Håvard (2019). Trenger 50 deltakere til fedmeforskning: – Ikke et slankeprosjekt. [Newspaper]. Gudbrandsdølen Dagningen.
• Stokland, Inger; Ellefsen, Stian & Hamarsland, Håvard (2019). Kristian (25) drikker tungtvann for å måle muskelstyrke: - Håper dette er starten på et sprekere liv. [Newspaper]. Gudbrandsdølen Dagningen.
• Støren, Øyvind; Rønnestad, Bent; Støa, Eva Maria; Hansen, Joar; Ellefsen, Stian & Ingjer, Frank [Show all 7 contributors for this article] (2019). Running velocity at lactate threshold: determining factors and relationships in well-trained and elite runners.
• Mølmen, Knut Sindre; Lian Lie, Anne Cecilie; Hammarström, Daniel; Lie Eriksen, Atle; Malerbakken, Bente & Ellefsen, Stian (2019). Tilpasninger til høy- og lavmotstandsstyrketrening for KOLS-rammede og friske, eldre personer.
• Mølmen, Knut Sindre; Lian Lie, Anne Cecilie; Hammarström, Daniel; Rønnestad, Bent; Lie Eriksen, Atle & Malerbakken, Bente [Show all 8 contributors for this article] (2019). ADAPTATIONS TO HIGH-LOAD AND LOW-LOAD RESISTANCE TRAINING IN COPD PATIENTS AND HEALTHY OLDER SUBJECTS.
• Hammarström, Daniel; Øfsteng, Sjur Johansen; Jacobsen, Nicolai; Flobergseter, Krister; Rønnestad, Bent & Ellefsen, Stian (2019). Characteristics of ribosomal accumulation during short-term resistance training with variable training volume and the effect of short-term de-training.
• Nygård, Håvard; Hammarström, Jens Konrad Daniel & Ellefsen, Stian (2019). Does vitamin d supplementation entail a 2x 2a fibertype shift? .
• Almquist, Nicki Winfield; Ellefsen, Stian; Ettema, Gertjan; Sandbakk, Øyvind & Rønnestad, Bent (2018). Effect of including 30-s sprints in prolonged endurance exercise on muscular adaptations and gross efficiency in highly trained cyclists.
• Mølmen, Knut Sindre; Ellefsen, Stian & Aasen, Ole Magnus (2018). The Granheim COPD Study: Kan styrketrening gi KOLS-pasienter bedre muskelstyrke og et bedre liv?
• Øfsteng, Sjur Johansen; Rønnestad, Bent; Jøsok, Øyvind; Helkala, Kirsi; Knox, Silje & Knox, Benjamin James [Show all 8 contributors for this article] (2017). Effects of high vs. moderate protein intake during a 10-days military exercise with energy deficit on muscular performance.
• Helkala, Kirsi; Knox, Benjamin James; Jøsok, Øyvind & Ellefsen, Stian (2017). Tunge vekter gjør hodet skarpere. [Newspaper]. Gudbransdølen Dagningen.
• Eftestøl, Einar; Egner, Ingrid Marie; Ellefsen, Stian; Andersen, Tom; Gundersen, Kristian & Bruusgaard, Jo C. (2016). The importance of mechanosensation in skeletal muscle hypertrophy.
• Ellefsen, Stian (2016). How to develop a top level research team?
• Ellefsen, Stian (2016). Trainsome - unravelling the heritability of performance.
• Rønnestad, Bent; Øfsteng, Sjur Johansen; Knox, Silje; Hammarström, Daniel; Helkala, Kirsi Marjaana & Knox, Benjamin James [Show all 9 contributors for this article] (2016). 10 RM vs 30 RM : Training load does matter.
• Ellefsen, Stian; Hammarström, Daniel & Rønnestad, Bent (2016). Strength training alters expression of genes involved in regulation of steroid hormone availability in M. Vastus Lateralis of untrained women.
• Hammarström, Daniel; Rønnestad, Bent; Blomstrand, E.; Whist, Jon Elling & Ellefsen, Stian (2016). Ribosome biogenesis and individual responses to strength-training of low and moderate volume.
• Ellefsen, Stian (2016). Trainsome – making responders out of non-responders.
• Ellefsen, Stian (2015). Redusert blodføring, svulmende legeme – en uvanlig treningsdagbok. Forskning.no. ISSN 1891-635X.
• Ellefsen, Stian (2015). Stoffer fra grønne tomater og epler kan motvirke mus­kel­svinn. ABCnyheter.no.
• Ellefsen, Stian & Buck, Daniel (2015). Laila røyket i over ti år. Nytt Kols-prosjekt skal hjelpe henne til et bedre liv. Gudbrandsdølen Dagningen.
• Vikmoen, Olav; Rønnestad, Bent; Ellefsen, Stian & Raastad, Truls (2015). Strength training improves cycling performance through improved fractional utilization of VO2max and cycling economy.
• Hammarström, Daniel; Rønnestad, Bent; Blomstrand, Eva & Ellefsen, Stian (2015). Myosin heavychain 2X expression interacts with acute regulation of PGC-1alpha splice-4 following strength exercise with low and moderate volume.
• Ellefsen, Stian; Hammarström, Daniel; Strand, Tor A; Nygård, Håvard; Whist, Jon Elling & Vegge, Geir [Show all 9 contributors for this article] (2015). Effects of Blood Flow-Restricted Strength Training and High-Load Strength Training on Muscular Endurance Characteristics.
• Rønnestad, Bent; Slettaløkken, Gunnar & Ellefsen, Stian (2015). Effect of adding whole body vibration to preconditioning exercise on sprint performance in well-trained cyclists.
• Ellefsen, Stian & Skaare, Sigrun Dancke (2015). Trener lår i forskningens tjeneste. Forskning.no. ISSN 1891-635X. Show summary

  Stian Ellefsen ble intervjuet i reportasjen som er skrevet av Sigrun Dancke Skaare. Fotograf er Lars Teppan Johansen.

• Vikmoen, Olav; Rønnestad, Bent; Ellefsen, Stian & Raastad, Truls (2014). Effect of heavy strength training on running performance determinants and performance in trained female endurance athletes.
• Ellefsen, Stian; Hammarström, Daniel; Vegge, Geir; Rønnestad, Bent; Whist, Jon Elling & Strand, T.A. [Show all 10 contributors for this article] (2014). The functional and biological efficacy of blood flowrestricted strength training in untrained women.
• Rønnestad, Bent; Hansen, Joar; Ellefsen, Stian & Spencer, Matthew (2014). Use it or lose it: In-season strength training cessation impairs performance variables in elite cyclists.
• Ellefsen, Stian (2014). Blogg. Forskeren forteller : Om sengeleie, muskelsvinn, blånisser og sånt. Forskning.no. ISSN 1891-635X.
• Hansen, Joar; Ellefsen, Stian & Rønnestad, Bent (2013). Kritiske til "terskeltrening". [Internet]. Dagens næringsliv (DN).
• Vikmoen, Olav; Rønnestad, Bent; Ellefsen, Stian & Raastad, Truls (2013). Effect of heavy strength training om performance determinants and performance in trained female cyclists.
• Slettaløkken, Gunnar; Ellefsen, Stian & Rønnestad, Bent (2013). Adding whole body vibration to pre conditioning exercise improves on-ice sprint performance in ice-hockey players.
• Ellefsen, Stian (2012). Nyhetsinnslag : Trening. [Radio]. P4.
• Ellefsen, Stian (2012). Nyhetsinnslag : Hormonpille. [Radio]. P4.
• Ellefsen, Stian (2012). Hvor mye vann har vi i kroppen? Gudbrandsdølen Dagningen. Show summary

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• Ellefsen, Stian (2012). Hvordan bli god i langrenn? Gudbrandsdølen Dagningen. Show summary

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• Fagernes, Cathrine Elisabeth; Ellefsen, Stian & Nilsson, Göran Erik (2014). Molecular background of ethanol production in anoxia tolerant fish. Akademika forlag. ISSN 1501-7710.

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