The Study
Effects of training frequency on muscular strength for trained men under volume matched conditions
This study is like a fair test where guys were randomly split into two workout plans: one with 2 heavy leg and chest days, another with 4 lighter full-body days. Both got stronger about the same, so we can say that doing more workouts per week didn’t make them stronger — as long as the total work was the same.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
This study asked if doing squats and bench press more times per week makes strong guys even stronger—if they do the same total amount of lifting.
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 554 / 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 strength gains are real and useful, but spreading workouts out doesn’t make you stronger—just feel easier.
- 2Both groups got stronger by about 7.7% to 11.5% in their lifts.
- 3The group that worked out four times didn’t get stronger than the group that worked out twice.
- 4But they felt less tired during the workouts, especially on squats.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
PeerJ
Year
2021
Authors
E. Johnsen, R. van den Tillaar
Related Content
Claims (5)
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.
If you're a guy who's been lifting weights for a while, working out each muscle four times a week doesn’t make you stronger than doing it twice a week—as long as you're doing the same total amount of work.
If you're a guy who's been lifting weights for a while, doing squats more often during the week—like four times instead of two—might feel easier and less tiring, especially after a few weeks.
If experienced guys do more sets of squats in one workout—like 5 or 6 instead of 2 or 3—they’ll feel more tired during that session, even if their total weekly workout volume stays the same.
If you're a guy who's been lifting weights for a while, doing either 2 or 4 workouts per week for each muscle can boost your strength by about 8–11% in just 8 weeks—as long as you do the same total amount of work overall.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.