Periodisation lifts your one-rep max but not your muscle size

Periodisation, the planned variation of training volume and intensity over time, is a cornerstone of strength coaching, yet its actual contribution has been surprisingly hard to pin down. Many comparisons are muddied because periodised programmes end up delivering different total volumes than non-periodised ones, making it impossible to tell whether the structure or the workload drove the result. This review asked two clean questions: with volume equated, does periodisation beat no periodisation for maximal strength and muscle growth, and does undulating variation beat the classic linear model?

The authors systematically searched PubMed, Scopus and SPORTDiscus, ultimately including 35 studies. Pooled analyses using a random effects model compared one-rep max strength and muscle hypertrophy outcomes between non-periodised and periodised training, and separately between linear periodisation, where load rises steadily over time, and undulating periodisation, where volume and intensity vary daily or weekly. Volume was equated between conditions from pre to post intervention, and subgroup analyses tested whether training status altered the findings. Other periodisation comparisons could not be analysed because too few studies existed.

Periodised training beat non-periodised training for one-rep max strength, with an overall effect of 0.31. Hypertrophy, by contrast, did not differ between periodised and non-periodised approaches. Comparing models, undulating periodisation beat linear periodisation for one-rep max overall, again with an effect of 0.31, but the subgroup analysis showed this advantage held only in trained participants, where the effect reached 0.61, while previously untrained lifters gained similarly under either model. Hypertrophy did not differ between linear and undulating periodisation either.

The finding that periodisation aids strength but not muscle size leads the authors to propose that its benefit may lie in the neurophysiological adaptations accompanying resistance training rather than in muscle growth itself. That reframes periodisation as primarily a strength tool. It also refines the audience: trained individuals appear to benefit from daily or weekly undulations in volume and intensity, whereas beginners progress similarly regardless of structure. How best to periodise beyond the linear and undulating models compared here remains open, since too few studies existed for other comparisons.

If your goal is a bigger one-rep max and you have training experience, this is a reason to think a structured plan that varies volume and intensity, particularly in an undulating pattern, could outperform doing the same thing every session. If you are new to lifting, the structure appears to matter far less for now. And if muscle size is the goal, this analysis suggests periodisation is not the lever that moves it: with volume held equal, growth came out the same either way.