The Study
Equal-Volume Strength Training With Different Training Frequencies Induces Similar Muscle Hypertrophy and Strength Improvement in Trained Participants
This study is like a fair test where people were randomly split into two workout plans—two days or four days per week—with the same total work. It shows both groups got stronger and built muscle equally, so it seems how you split the workouts doesn’t matter much when total work is the same.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
This study checked if working out 4 times a week is better than 2 times a week for getting stronger and building muscle, as long as the total workout amount is the same.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 568 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The results suggest that how often you train matters less than how much you do overall, and that practicing an exercise you're less familiar with can lead to bigger strength gains.
- 2People got equally stronger and built the same amount of muscle whether they worked out 2 or 4 times a week.
- 3But they got much stronger on machine exercises (like chest press) than on free weights (like bench press), even though both were trained the same way.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Physiology
Year
2022
Authors
H. Hamarsland, Hermann Moen, Ole Johannes Skaar, Preben Wahlstrøm Jorang, Håvard Saeterøy Rødahl, B. Rønnestad
Related Content
Claims (10)
When the total amount of weight training per week is the same, changing how often you train—such as once a week versus five times a week—does not change the amount of muscle growth.
When the total amount of exercise is kept the same, increasing workouts from once to twice per week does not result in a meaningful difference in muscle growth.
For the same total number of weekly sets, changing how those sets are spread across training days does not change muscle growth.
If you spread your workouts over more days each week but keep the total work the same, you'll get stronger—but your muscles won't necessarily grow bigger.
For adults who regularly lift weights, spreading the same total amount of heavy lifting over two days per week produces the same gains in muscle size as spreading it over four days per week, when the total weekly volume is unchanged.
Among adults with moderate resistance training experience, using weight machines leads to greater increases in strength than using free weights over nine weeks, regardless of how often they train, because familiarity with the movement matters more than how complex the movement is.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.