How often should I train to maximize gains in muscle size and strength?

For muscle gain, each muscle group should be trained at least once per week. The available evidence generally does not indicate a benefit to higher training frequencies,^[1] particularly when volume is equated between interventions. However, it seems likely that when weekly training volume exceeds 10 sets per week, a higher training frequency would be advantageous, as opposed to performing 10+ sets for a muscle group in a single session.^[2]

For strength, training frequency can be conceptualized as the number of times per week an exercise is performed, as strength is ultimately specific to the test being used to assess it. In accordance with the data on muscle gain, there does not appear to be an advantage to training frequencies of more than once per week in the context of volume-equated training programs.^[3][4]

It’s important to highlight that the above data represents the average response, which may not apply to the reader, as the response to a given training frequency can radically differ between individuals.

In one study that had participants perform high-frequency (5x per week) resistance exercise with one leg and low frequency (2x or 3x per week) resistance exercise with the other leg, it was found that some individuals gained more muscle and strength on the leg assigned to the high-frequency condition and some individuals gained more muscle and strength on the leg assigned to the low-frequency condition, while others experienced no difference between conditions.^[5]

Furthermore, only about 32% of individuals displayed an aligned response, i.e., the same resistance training frequency was better for both muscle gain and strength. Therefore, it’s prudent that the individuals experiment with different training frequencies to find what works best for them for increasing muscle size and strength.