Periodized resistance training produces greater maximal-strength gains than non-periodized training (ES 0.43, 18 studies)
Key Findings
Random-effects meta-analysis of 81 effects from 18 studies (1988-2015) comparing periodized with non-periodized resistance training on 1RM squat, bench press or leg press.
Periodized training improved 1RM more than non-periodized training: ES = 0.43 (95% CI 0.27-0.58; P < 0.001) — a moderate effect per the authors.
Moderators: periodization model (β = 0.51), training status (β = -0.59), study length (β = 0.03) and training frequency (β = 0.46) were associated with the change in 1RM.
Undulating programs were more favourable for strength gains; gains were larger in untrained participants, and higher training frequency and longer studies were linked to larger improvements.
Practical Application
Across 18 studies (81 effects), periodized resistance training raised 1RM more than non-periodized training (ES 0.43, 95% CI 0.27-0.58), with undulating models, higher frequency and longer programs doing best — vary load and volume across sessions and weeks rather than repeating identical sessions.
The advantage was larger in untrained participants; for trained lifters expect a smaller edge.
Limitations
Pools varied models and populations across 18 mostly older studies; the periodised-vs-not gap is moderate.
Moderator associations are across studies, not tested head-to-head.
How this entry was checked and changed
Content correction 2026-09-27
Added the pooled effect (ES 0.43, 95% CI 0.27-0.58, 18 studies / 81 effects) and the moderators from the abstract.
"Any coherent periodised model beats none; pick one you can adhere to" -> the abstract found undulating programs more favourable; line replaced.