Doing more total work (more sets or weight) is what makes you stronger and bigger—not just doing it more often. Frequency only helps if it lets you do more work.
Scientific Claim
The effect size of strength and hypertrophy gains from higher training frequency is medium (ES = 0.51–0.63) only when total volume is increased, suggesting volume is the primary driver of adaptation, not frequency per se.
Original Statement
“When the higher RT frequency allowed the application of a greater TTV (i.e., RTUV), higher effect size (ES) values (0.51 and 0.63, 1RM and CSA, respectively) were observed for the adaptations.”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
Authors imply frequency 'allows' greater volume and thus greater gains, but the design confounds frequency and volume; the association between volume and gains is valid, but causation cannot be attributed to frequency.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Systematic Review & Meta-AnalysisLevel 1aWhether total training volume is a stronger predictor of strength and hypertrophy outcomes than training frequency in trained individuals.
Whether total training volume is a stronger predictor of strength and hypertrophy outcomes than training frequency in trained individuals.
What This Would Prove
Whether total training volume is a stronger predictor of strength and hypertrophy outcomes than training frequency in trained individuals.
Ideal Study Design
A meta-regression of 20+ RCTs in trained men comparing 1x, 2x, and 3x/week frequencies, with total volume as a continuous covariate, and 1RM and CSA as outcomes, using individual participant data.
Limitation: Cannot prove causation; relies on published data quality and reporting.
Randomized Controlled TrialLevel 1bCausal effect of total volume on strength/hypertrophy, independent of frequency, in trained men.
Causal effect of total volume on strength/hypertrophy, independent of frequency, in trained men.
What This Would Prove
Causal effect of total volume on strength/hypertrophy, independent of frequency, in trained men.
Ideal Study Design
A 4-arm RCT with 80 trained men: (1) 1x/week, low volume; (2) 1x/week, high volume; (3) 3x/week, low volume; (4) 3x/week, high volume; all matched for intensity and duration, measuring 1RM and CSA via MRI.
Limitation: Logistically complex; blinding not feasible.
Evidence from Studies
Supporting (1)
Effect of different training frequencies on maximal strength performance and muscle hypertrophy in trained individuals—a within-subject design
When people lift weights more often but don’t do more total work, they don’t get stronger or bigger faster. But if lifting more often lets them do more total work, then they see better results — meaning it’s the total work that matters, not just how often they lift.