Meta-analysis — 2019 — Training frequency · Hypertrophy
How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency
What did the researchers investigate?
Whether training a muscle more often per week increases muscle growth, across 25 studies.
What did they find?
With weekly volume equated, there was no significant difference between higher and lower frequencies, including in trained people and for upper and lower body. Without volume matched, higher frequencies showed a modest advantage.
What does this mean for training?
For a given number of weekly sets, you can choose how often to train a muscle based on preference and schedule.
How does FitX AI use this evidence?
FitX AI lets you choose once or twice a week per muscle, and keeps the weekly sets the same either way.
Where FitX AI's own choices go beyond this paper
Once or twice a week. Twice a week is a default that spreads the sets, not a requirement.
Limitations
Where higher frequency helped, volume was not matched, so the benefit may come from the extra sets rather than the frequency itself.