Training frequency per muscle group, at equal volume
Across 67 studies of 2058 participants, this multi-level meta-regression found that gains in muscle size and strength increase as weekly set volume increases (posterior probability that the marginal slope exceeded zero: 100% for both outcomes), though both best-fit models suggest diminishing returns, with those for strength considerably more pronounced. For weekly frequency, the posterior probability of the slope exceeding zero for hypertrophy was less than 100%, which the authors describe as compatible with negligible effects; in contrast, the probability for strength was 100%, suggesting strength gains increase with increasing frequency, albeit with diminishing returns. The authors conclude that the dose-response relationship between frequency and hypertrophy appears to differ from that with strength, as only the latter exhibits consistently identifiable effects. All models were adjusted for the duration of the intervention and training status; the abstract does not state that weekly volume was among the adjustments, so on the abstract alone the frequency-strength association cannot be separated from weekly volume.
Pelland JC (2026) · Sports medicine (Auckland, N.Z.) · PMID 41343037
It does NOT say frequency is irrelevant across the board. In the same paper, strength gains did increase with frequency at a posterior probability of 100%, so "frequency doesn't matter" is an overclaim the paper contradicts on the strength side.
It does NOT report a specific probability figure for frequency-on-hypertrophy. The abstract says only "less than 100%." Any precise percentage on a card would be fabricated.
It does NOT demonstrate equivalence. Compatibility with negligible effects is an absence of a consistently identifiable effect, not proof of no effect.
It does NOT separate frequency from weekly volume. The abstract's only stated adjustment set is duration of the intervention and training status; weekly volume is not named among the adjustments, and the string "equated" does not appear anywhere in the abstract. More sessions plausibly carry more sets, so no field may attribute the strength result to frequency specifically until the full text shows the frequency models adjusted for volume.
It does NOT license cramming a week's work into one session. The abstract reports frequency models adjusted for intervention duration and training status; it does not describe a volume-equated head-to-head frequency contrast, and it does not test the extreme low-frequency end.
It does NOT say volume is unlimited. Both best-fit models suggest diminishing returns, with those for strength considerably more pronounced.
It does NOT establish that the pooled studies were randomised controlled trials. Neither the abstract nor the PubMed publication types state randomisation, so this cannot be graded as a meta-analysis of RCTs.
It does NOT generalise beyond a sample averaging 25.16 years that was 79.1% male.
Every figure below is shown with the sentence it was taken from, so you can check it against the paper rather than trusting us.
- 100%posterior probability
Probability that the volume slope is above zero for both hypertrophy and strength — more weekly sets tracked with more muscle and more strength.
The posterior probability of the marginal slope exceeding zero for the effect of volume on both hypertrophy and strength was 100%, indicating that gains in muscle size and strength increase as volume increases.
- less than 100%posterior probability
Probability that the frequency slope is above zero for muscle growth. The abstract gives no exact figure and describes the result as compatible with negligible effects. Print this string verbatim — never substitute a number.
The posterior probability of the marginal slope exceeding zero for frequency's effect on hypertrophy was less than 100%, indicating compatibility with negligible effects.
- 100%posterior probability
Probability that the frequency slope is above zero for strength — the contrast that stops this being a blanket 'frequency doesn't matter' claim. The sentence opens with 'In contrast,' so quote it with its antecedent or reword, and carry the trailing 'albeit with diminishing returns'.
In contrast, the posterior probability for strength was 100%, suggesting strength gains increase with increasing frequency, albeit with diminishing returns.
- 67studies
Number of studies entering the multi-level meta-regressions. Verified under whitespace normalisation; the sentence's non-ASCII spaces (U+2009, U+00A0) around the age span are an encoding artefact, not a quotation failure.
A series of multi-level meta-regressions were performed for muscle hypertrophy and strength, utilizing 67 total studies of 2058 participants (79.1% male, 20.9% female; average age 25.16 ± 5.22 years).
- 2058participants
Total pooled participants across the 67 studies. Same sentence and same encoding caveat as STUDIES_POOLED.
A series of multi-level meta-regressions were performed for muscle hypertrophy and strength, utilizing 67 total studies of 2058 participants (79.1% male, 20.9% female; average age 25.16 ± 5.22 years).
2058 participants pooled from 67 studies; 79.1% male, 20.9% female; average age 25.16 ± 5.22 years. The abstract reports no age range and states no exclusion of older or clinical participants. Training status was entered as a model covariate; all models were adjusted for duration of the intervention and training status. The abstract does not name which training statuses were pooled. The sample is heavily male-weighted, so the female evidence base here is thin.
Pelland JC, et al. (2026)The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains.
Sports medicine (Auckland, N.Z.) · PMID 41343037
Meta-regression · 67 total studies · 2058 participants (79.1% male, 20.9% female; average age 25.16 ± 5.22 years)
Who funded itAuthors declare no conflicts of interest.
Volume, rep ranges, rest, stretching, sleep — each with its numbers and its limits.
Every figure is machine-checked against the sentence it came from. Including what that does not guarantee.
Repstra handles the programming, check-ins and admin so the conversation you have with a client is the coaching one. Free for your first 5 clients, 0% commission on your own.
See how it works