Fredrik Tonstad Vårvik

Doctoral Research Fellow

Department of Sport Science and Physical Education

Email: fredrik.t.varvik@uia.no
Phone: +47 38142219
Mobile phone: +4792854969

Office I3044 (Universitetsveien 25, 4630 Kristiansand, Norway)

Research groups

SPADE: Sports Performance and Athlete Development Environments

Areas of responsibility

My Ph.D. topic investigates how to optimize in-season strength training for team sport athletes aiming to maintain muscle size, strength, power, and match freshness throughout the competitive season. We compare the effect of heavy load strength training versus power- and plyometric training programs, with an emphasis on female handball athletes.

Resistance training and sports nutrition are my main interests, particularly in the areas of recovery, adaptation, and performance. I teach and supervise students and am involved in research projects on these topics, in addition to being a consultant at the Norwegian Olympic Committee.

I have completed two bachelor's degrees in Sports Science and Nutrition, a master's in Exercise Physiology, and the IOC Sports Nutrition diploma.

Tuition

Exercise physiology, strength training (theory and practice) and sports nutrition.

Fosstveit, Sindre Herskedal; Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Sibayan, Erlend E.; Fjeller, Joachim S. & Løvold, Sondre [Show all 10 contributors for this article] (2023). Associations between Power Training-Induced Changes in Body Composition and Physical Function in Older Men: A Pre-Test–Post-Test Experimental Study. International Journal of Environmental Research and Public Health (IJERPH). ISSN 1661-7827. 20(22). doi: 10.3390/ijerph20227070. Full text in Research Archive Show summary
It is well-established that cross-sectional measurements of poor body composition are associated with impaired physical function and that power training effectively enhances total lean mass and physical function in older adults. However, it is unclear if power training-induced changes in body composition are associated with improved physical function in older adults. Aim: The present study investigated associations between body composition and physical function cross-sectionally and with power training-induced changes in older men. Methods: Forty-nine older men (68 ± 5 yrs) completed a 10-week biweekly power training intervention. Body composition was measured using dual-energy X-ray absorptiometry. Physical function was assessed as a composite Z-score combining measures from Sit-to-stand power, Timed up-and-go time, and loaded and unloaded Stair-climbing time (15 steps). Linear and quadratic regression analyses were performed to assess associations between body composition and physical function. Results: At baseline, total (R2 = 0.11, p < 0.05) and percentage body fat (R2 = 0.15, p < 0.05) showed a non-linear relationship with physical function. The apex of the quadratic regression for body composition was 21.5% body fat. Furthermore, there was a non-linear relationship between changes in body fat percentage and physical function from pre- to post-intervention (R2 = 0.15, p < 0.05). Conclusion: The present study’s findings indicate that participants with a body composition of ~20% body fat displayed the highest level of physical function at baseline. Furthermore, despite small pre–post changes in body fat, the results indicate that those who either preserved their body fat percentage or experienced minor alterations observed the greatest improvements in physical function.
Haugen, Markus Estifanos; Vårvik, Fredrik Tonstad; Grgic, Jozo; Studsrud, Henrik; Austheim, Espen & Zimmermann, Erik Mathias [Show all 10 contributors for this article] (2023). Effect of isolated and combined ingestion of caffeine and citrulline malate on resistance exercise and jumping performance: a randomized double-blind placebo-controlled crossover study. European Journal of Nutrition. ISSN 1436-6207. 62(7), p. 2963–2975. doi: 10.1007/s00394-023-03212-x. Full text in Research Archive Show summary
Purpose The aim of this study was to explore the isolated and combined efects of cafeine and citrulline malate (CitMal) on jumping performance, muscular strength, muscular endurance, and pain perception in resistance-trained participants. Methods Using a randomized and double-blind study design, 35 resistance-trained males (n=18) and females (n=17) completed four testing sessions following the ingestion of isolated cafeine (5 mg/kg), isolated CitMal (12 g), combined doses of cafeine and CitMal, and placebo. Supplements were ingested 60 min before performing a countermovement jump (CMJ) test (outcomes included jump height, rate of force development, peak force, and peak power), one-repetition maximum (1RM) squat and bench press, and repetitions to muscular failure in the squat and bench press with 60% of 1RM. Pain perception was evaluated following the repetitions to failure tests. The study was registered at ISRCTN (registration number: ISRCTN11694009). Results Compared to the placebo condition, isolated cafeine ingestion and co-ingestion of cafeine and CitMal signifcantly enhanced strength in 1RM bench press (Cohen’s d: 0.05–0.06; 2.5–2.7%), muscular endurance in the squat (d: 0.46–0.58; 18.6–18.7%) and bench press (d: 0.48–0.64; 9.3–9.5%). However, there was no signifcant diference between isolated cafeine ingestion and cafeine co-ingested with CitMal, and isolated CitMal supplementation did not have an ergogenic efect in any outcome. No main efect of condition was found in the analysis for CMJ-derived variables, 1RM squat and pain perception. Conclusion Cafeine ingestion appears to be ergogenic for muscular strength and muscular endurance, while adding CitMal does not seem to further enhance these efects.
Haugen, Markus Estifanos; Vårvik, Fredrik Tonstad; Larsen, Stian; Haugen, Arvid Steinar; van den Tillaar, Roland Johannes Wilhelmus & Bjørnsen, Thomas (2023). Effect of free-weight vs. machine-based strength training on maximal strength, hypertrophy and jump performance – a systematic review and meta-analysis. BMC sports science, medicine and rehabilitation. ISSN 2052-1847. 15(1). doi: 10.1186/s13102-023-00713-4. Full text in Research Archive Show summary
Background The efectiveness of strength training with free-weight vs. machine equipment is heavily debated. Thus, the purpose of this meta-analysis was to summarize the data on the efect of free-weight versus machine-based strength training on maximal strength, jump height and hypertrophy. Methods The review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, and the systematic search of literature was conducted up to January 1st, 2023. Studies that directly compared free-weight vs. machine-based strength training for a minimum of 6 weeks in adults (18–60 yrs.) were included. Results Thirteen studies (outcomes: maximal strength [n=12], jump performance [n=5], muscle hypertrophy [n=5]) with a total sample of 1016 participants (789 men, 219 women) were included. Strength in free-weight tests increased signifcantly more with free-weight training than with machines (SMD: -0.210, CI: -0.391, -0.029, p=0.023), while strength in machine-based tests tended to increase more with machine training than with free-weights (SMD: 0.291, CI: -0.017, 0.600, p=0.064). However, no diferences were found between modalities in direct comparison (free-weight strength vs. machine strength) for dynamic strength (SMD: 0.084, CI: -0.106, 0.273, p=0.387), isometric strength (SMD: -0.079, CI: -0.432, 0.273, p=0.660), countermovement jump (SMD: -0.209, CI: -0.597, 0.179, p=0.290) and hypertrophy (SMD: -0.055, CI: -0.397, 0.287, p=0.751). Conclusion No diferences were detected in the direct comparison of strength, jump performance and muscle hypertrophy. Current body of evidence indicates that strength changes are specifc to the training modality, and the choice between free-weights and machines are down to individual preferences and goals.
Byrkjedal, Per Thomas; Thunshelle, Atle; Spencer, Matthew; Luteberget, Live Steinnes; Ivarsson, Andreas & Vårvik, Fredrik Tonstad [Show all 8 contributors for this article] (2023). In-season autoregulation of one weekly strength training session maintains physical and external load match performance in professional male football players. Journal of Sports Sciences. ISSN 0264-0414. 41(6), p. 536–546. doi: 10.1080/02640414.2023.2227536. Full text in Research Archive Show summary
The aim of this study was to compare the effects of autoregulating strength training volume based on an objective (external load match performance) versus a subjective (self-selected) method in professional male football players. Sixteen players completed a 10-week strength training programme where the number of sets was regulated based on football match high-intensity running distance (HIR >19.8 km/h, AUTO, n = 7), or self-selected (SELF, n = 9). In addition to traditional physical performance assessments (30-m sprint, countermovement jump, leg-strength, and body composition), external load match performance was assessed with five matches in the beginning and in the end of the study period. Both groups performed ~ 1 weekly bout of ~ 6 sets in leg extensor exercises during the 10-week period, and maintained physical performance during the competitive season, with no group differences detected after the training period. Non-overlap of all pairs (NAP) analysis showed weak-to-moderate effects in external load match performance from before to after the study period, suggesting that players maintained or improved their performance. In conclusion, no group differences were observed, suggesting that both external load autoregulated and self-selected, low-volume in-season strength training maintained physical, and external load match performance in professional male football players.
Siedler, Madelin R.; Lewis, Megan H.; Trexler, Eric T.; Lamadrid, Priscila; Waddell, Brian J. & Bishop, Sarah F. [Show all 13 contributors for this article] (2023). The Effects of Intermittent Diet Breaks during 25% Energy Restriction on Body Composition and Resting Metabolic Rate in Resistance-Trained Females: A Randomized Controlled Trial. The Journal of Human Kinetics. ISSN 1640-5544. 86, p. 117–132. doi: 10.5114/jhk/159960. Show summary
The purpose of this study was to examine the effects of intermittent versus continuous energy restriction on body composition, resting metabolic rate, and eating behaviors in resistance-trained females. Thirty-eight resistance-trained females (mean ± standard deviation age: 22.3±4.2 years) were randomized to receive either six weeks of a continuous 25% reduction in energy intake (n= 18), or one week of energy balance after every two weeks of 25% energy restriction (eight weeks total; n= 20). Participants were instructed to ingest 1.8 g protein/kilogram bodyweight per day and completed three weekly supervised resistance training sessions throughout the intervention. There were no differences between groups for changes over time in body composition, resting metabolic rate, or seven of the eight measured eating behavior variables (p > 0.05). However, a significant group-by-time interaction for disinhibition (p < 0.01) from the Three-Factor Eating Questionnaire was observed, with values (± standard error) in the continuous group increasing from 4.91 ± 0.73 to 6.17 ± 0.71, while values in the intermittent group decreased from 6.80 ± 0.68 to 6.05 ± 0.68. Thus, diet breaks do not appear to induce improvements in body composition or metabolic rate in comparison with continuous energy restriction over six weeks of dieting, but may be employed for those who desire a short-term break from an energy-restricted diet without fear of fat regain. While diet breaks may reduce the impact of prolonged energy restriction on measures of disinhibition, they also require a longer time period that may be less appealing for some individuals.
Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Vårvik, Fredrik Tonstad; Paulsen, Gøran; Joensen, Malene & Kristoffersen, Morten [Show all 11 contributors for this article] (2023). The effects of being told you are in the intervention group on training results: a pilot study. Scientific Reports. ISSN 2045-2322. 13(1), p. 1–10. doi: 10.1038/s41598-023-29141-7. Full text in Research Archive Show summary
Little is known about the placebo effects when comparing training interventions. Consequently, we investigated whether subjects being told they are in the intervention group get better training results compared to subjects being told they are in a control group. Forty athletes (male: n = 31, female: n = 9) completed a 10-week training intervention (age: 22 ± 4 years, height: 183 ± 10 cm, and body mass: 84 ± 15 kg). After randomization, the participants were either told that the training program they got was individualized based on their force–velocity profile (Placebo), or that they were in the control group (Control). However, both groups were doing the same workouts. Measurements included countermovement jump (CMJ), 20-m sprint, one-repetition maximum (1RM) back-squat, a leg-press test, ultrasonography of muscle-thickness (m. rectus femoris), and a questionnaire (Stanford Expectations of Treatment Scale) (Younger et al. in Clin Trials 9(6):767–776, 2012). Placebo increased 1RM squat more than Control (5.7 ± 6.4% vs 0.9 ± 6.9%, [0.26 vs 0.02 Effect Size], Bayes Factor: 5.1 [BF10], p = 0.025). Placebo had slightly higher adherence compared to control (82 ± 18% vs 72 ± 13%, BF10: 2.0, p = 0.08). Importantly, the difference in the 1RM squat was significant after controlling for adherence (p = 0.013). No significant differences were observed in the other measurements. The results suggest that the placebo effect may be meaningful in sports and exercise training interventions. It is possible that ineffective training interventions will go unquestioned in the absence of placebo-controlled trials.
Lindberg, Kolbjørn Andreas; Lohne-Seiler, Hilde; Fosstveit, Sindre Herskedal; Sibayan, Erlend E.; Fjeller, Joachim S. & Løvold, Sondre [Show all 12 contributors for this article] (2022). Effectiveness of individualized training based on force–velocity profiling on physical function in older men. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 32(6), p. 1013–1025. doi: 10.1111/sms.14157. Full text in Research Archive Show summary
The study aimed to investigate the effectiveness of an individualized power training program based on force–velocity (FV) profiling on physical function, muscle morphology, and neuromuscular adaptations in older men. Forty-nine healthy men (68 ± 5 years) completed a 10-week training period to enhance muscular power. They were randomized to either a generic power training group (GPT) or an individualized power training group (IPT). Unlike generic training, individualized training was based on low- or high-resistance exercises, from an initial force–velocity profile. Lower-limb FV profile was measured in a pneumatic leg-press, and physical function was assessed as timed up-and-go time (TUG), sit-to-stand power, grip strength, and stair-climbing time (loaded [20kg] and unloaded). Vastus lateralis morphology was measured with ultrasonography. Rate of force development (RFD) and rate of myoelectric activity (RMA) were measured during an isometric knee extension. The GPT group improved loaded stair-climbing time (6.3 ± 3.8 vs. 2.3% ± 7.3%, p = 0.04) more than IPT. Both groups improved stair-climbing time, sit to stand, and leg press power, grip strength, muscle thickness, pennation angle, fascicle length, and RMA from baseline (p < 0.05). Only GPT increased loaded stair-climbing time and RFD (p < 0.05). An individualized power training program based on FV profiling did not improve physical function to a greater degree than generic power training. A generic power training approach combining both heavy and low loads might be advantageous through eliciting both force- and velocity-related neuromuscular adaptions with a concomitant increase in muscular power and physical function in older men.
Henselmans, Menno; Bjørnsen, Thomas; Hedderman, Richie & Vårvik, Fredrik Tonstad (2022). The Effect of Carbohydrate Intake on Strength and Resistance Training Performance: A Systematic Review . Nutrients. ISSN 2072-6643. 14(4). doi: 10.3390/nu14040856. Full text in Research Archive Show summary
High carbohydrate intakes are commonly recommended for athletes of various sports, including strength trainees, to optimize performance. However, the effect of carbohydrate intake on strength training performance has not been systematically analyzed. A systematic literature search was conducted for trials that manipulated carbohydrate intake, including supplements, and measured strength, resistance training or power either acutely or after a diet and strength training program. Studies were categorized as either (1) acute supplementation, (2) exercise-induced glycogen depletion with subsequent carbohydrate manipulation, (3) short-term (2–7 days) carbohydrate manipulation or (4) changes in performance after longer-term diet manipulation and strength training. Forty-nine studies were included: 19 acute, six glycogen depletion, seven short-term and 17 long-term studies. Participants were strength trainees or athletes (39 studies), recreationally active (six studies) or untrained (four studies). Acutely, higher carbohydrate intake did not improve performance in 13 studies and enhanced performance in six studies, primarily in those with fasted control groups and workouts with over 10 sets per muscle group. One study found that a carbohydrate meal improved performance compared to water but not in comparison to a sensory-matched placebo breakfast. There was no evidence of a dose-response effect. After glycogen depletion, carbohydrate supplementation improved performance in three studies compared to placebo, in particular during bi-daily workouts, but not in research with isocaloric controls. None of the seven short-term studies found beneficial effects of carbohydrate manipulation. Longer-term changes in performance were not influenced by carbohydrate intake in 15 studies; one study favored the higher- and one the lower-carbohydrate condition. Carbohydrate intake per se is unlikely to strength training performance in a fed state in workouts consisting of up to 10 sets per muscle group. Performance during higher volumes may benefit from carbohydrates, but more studies with isocaloric control groups, sensory-matched placebos and locally measured glycogen depletion are needed.
Vårvik, Fredrik Tonstad (2021). Dette kan påvirke OL-prestasjonene . Stavanger Aftenblad. ISSN 0804-8991.
Vårvik, Fredrik Tonstad; Bjørnsen, Thomas & Gonzalez, Adam (2021). Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis. International Journal of Sport Nutrition & Exercise Metabolism. ISSN 1526-484X. 31(4), p. 350–358. doi: 10.1123/ijsnem.2020-0295.
Roberts, Justin; Zinchenko, Anastasia; Mahbubani, Krishnaa T.; Johnstone, James; Smith, Lee & Merzbach, Viviane [Show all 11 contributors for this article] (2018). Satiating Effect of High Protein Diets on Resistance-Trained Subjects in Energy Deficit. Nutrients. ISSN 2072-6643. 11(7). doi: 10.3390/nu11010056.

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Vårvik, Fredrik Tonstad; Bjørnsen, Thomas; Torstveit, Monica Klungland; Pedersen, Silje Marie; Granli, Aslak & Aune, Simon S. [Show all 7 contributors for this article] (2023). Effects of in-season high-load strength training versus higher-velocity power training in female handball players: Are the adaptations training load- and velocity-specific?
Bjørnsen, Thomas; Remme, Sander; Haukali, Eirik; Tveitevoll, Åsmund & Vårvik, Fredrik Tonstad (2023). MAXIMIZING PHYSICAL PERFORMANCE WITH STRENGTH TRAINING DURING THE COMPETITIVE SEASON FOR ICE HOCKEY PLAYERS: FAVORABLE EFFECTS OF 40% VELOCITY LOSS.
Vårvik, Fredrik Tonstad; Bjørnsen, Thomas; Torstveit, Monica Klungland; Pedersen, Silje Marie; Granli, Aslak & Aune, Simon S. [Show all 8 contributors for this article] (2023). MAXIMIZING PHYSICAL PERFORMANCE IN FEMALE HANDBALL PLAYERS DURING THE COMPETITIVE SEASON: THE IMPACT OF HIGH-LOAD STRENGTH TRAINING VERSUS POWER-PLYOMETRIC TRAINING.
Byrkjedal, Per Thomas; Thunshelle, Atle; Spencer, Matthew; Luteberget, Live Steinnes; Ivarsson, Andreas & Vårvik, Fredrik Tonstad [Show all 8 contributors for this article] (2023). In-season autoregulation of one weekly strength training session maintains physical performance in professional male football players.
Vårvik, Fredrik Tonstad & Bjørnsen, Thomas (2022). Hvor viktig er karbohydratene for treningen din? .
Fosstveit, Sindre Herskedal; Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Sibayan, Erlend E.; Fjeller, Joachim S. & Løvold, Sondre [Show all 10 contributors for this article] (2022). Associations between power training-induced changes in body composition and physical function in older men: a pretest-posttest experimental study. .
Lohne-Seiler, Hilde; Lindberg, Kolbjørn Andreas; Fosstveit, Sindre Herskedal; Sibayan, Erlend E.; Fjeller, Joachim S. & Løvold, Sondre [Show all 11 contributors for this article] (2022). Physical function and health-related quality of life in older men after 10-weeks power training – any associations?
Vårvik, Fredrik Tonstad & Bjørnsen, Thomas (2022). Hvor viktig er karbohydratene for treningen din? lokalavisen fedrelandsvennen.
Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Vårvik, Fredrik Tonstad; Paulsen, Gøran; joensen, malene & Kristoffersen, Morten [Show all 11 contributors for this article] (2022). When You Believe You Are In The Intervention Group, You Will Get Better Training Results. A Randomized Controlled Placebo Study .
Bjørnsen, Thomas; Hody, Stephanie; Raastad, Truls; Paulsen, Gøran; Wernbom, Mathias & Vårvik, Fredrik Tonstad [Show all 8 contributors for this article] (2022). High-Frequency Blood Flow Restricted Resistance Exercise To Failure Induces Higher Cellular Stress In Muscle Fibres Than A Non-Failure Protocol .
Vårvik, Fredrik Tonstad; Bjørnsen, Thomas; Granli, Aslak & Lindberg, Kolbjørn Andreas (2022). Time Course Of Recovery Following Work-Matched Strength-Oriented- Versus Power-Oriented Resistance Exercise Bouts.
Fosstveit, Sindre Herskedal; Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Vårvik, Fredrik Tonstad; Berntsen, Sveinung & Seiler, Hilde Lohne (2022). Associations between power training-induced changes in body composition and physical function in older men: a pretest-posttest experimental study.
Vårvik, Fredrik Tonstad (2021). Dette kan påvirke OL-prestasjonene . Adresseavisen. ISSN 0805-3804.
Vårvik, Fredrik Tonstad (2021). Dette kan påvirke OL-prestasjonene . Romsdals Budstikke.. ISSN 0806-5160.
Vårvik, Fredrik Tonstad (2021). Dette kan påvirke OL-prestasjonene . Folkebladet.no.
Vårvik, Fredrik Tonstad (2021). Dette kan påvirke OL-prestasjonene. Fædrelandsvennen. ISSN 0805-3790.
Vårvik, Fredrik Tonstad (2021). Dette skjer i kroppen når du restituerer. [Newspaper]. ShapeUp.
Henselmans, Menno; Bjørnsen, Thomas; Hedderman, Richie & Vårvik, Fredrik Tonstad (2021). Can acute or long-term manipulation of carbohydrate availability increase strength performance? .
Henselmans, Menno; Bjørnsen, Thomas; Hedderman, Richie & Vårvik, Fredrik Tonstad (2021). Carbohydrate requirements for strength training performance: a systematic review.
Fosstveit, Sindre Herskedal; Seiler, Hilde Lohne; Lindberg, Kolbjørn Andreas; Berntsen, Sveinung; Bjørnsen, Thomas & Vårvik, Fredrik Tonstad (2020). The effect of individualized power training based on the least developed capacity in force-velocity profiles of elderly men.
Vårvik, Fredrik Tonstad; Bjørnsen, Thomas & Gonzalez, Adam (2020). Acute effect of citrulline malate on repetition performance during strength training: A systematic review and meta-analysis.

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Published Apr. 16, 2024 11:24 AM