Meta-analysis — 2022 — Periodization · Strength · Hypertrophy
Effects of Periodization on Strength and Muscle Hypertrophy in Volume-Equated Resistance Training Programs: A Systematic Review and Meta-analysis
What did the researchers investigate?
Periodized versus non-periodized training, and linear versus undulating periodization, with training volume equated, across 35 studies.
What did they find?
Periodized training improved 1RM strength more than non-periodized training. Undulating beat linear periodization for 1RM, but only in trained participants. Muscle growth did not differ between any of the approaches.
What does this mean for training?
Structuring training in phases helps strength. For muscle growth, total work matters more than how it is arranged.
How does FitX AI use this evidence?
FitX AI runs training in 5-week blocks with rising effort and a deload, and reviews each block to set the next one.
Where FitX AI's own choices go beyond this paper
RPE mesocycle. The 7, 8, 9, 10 ladder and the 5-week length are FitX AI design choices. The papers support training near failure and RPE/RIR as effort scales, not this exact schedule.
End-of-block review. The 10% cap and the review rules are FitX AI choices. Periodization trials compare programme designs; they do not validate this method.
Limitations
Results were limited to volume-equated designs; some comparisons had too few studies to analyse.