Strength Training Frequency: Does Training More Often Pay Off?

If you’ve been sweating over how many times a week you should hit the weights to maximize strength and muscle growth, you’re not alone. Few topics in the fitness industry are more highly debated than training frequency.

Except perhaps for training volume.

Funnily enough, they tie closely together, as evidenced by a study conducted by researchers at the University of São Paulo.¹ It tackles this very question, offering insights into how often you should train a muscle group for the best gains in strength and muscle mass.

The Study at a Glance

The study in question explored whether training more frequently leads to greater gains in muscle growth and strength when total training volume (the total amount of weight lifted) is kept consistent.

Twenty-four experienced male lifters, averaging six years of training experience, participated in a 9-week strength training program that focused exclusively on the unilateral 45-degree leg press.

The participants trained their right and left legs with either one or three weekly sessions.

Within-Subject Study Design

What sets this study apart from most other strength-training studies is its within-subject design. That means that the same participants are used for all conditions of an experiment, so they act as their own control.

Unlike traditional methods where different groups follow different protocols, this study had each participant train one leg at a higher frequency (3x/week) and the other at a lower one (1x/week).

This approach pretty much eliminates variability in the study results from individual differences. Things like genetics, baseline strength, or nutrition, which can all skew results in between-subject studies, don’t matter if you compare yourself to… well, yourself.

How the Study Was Done

The participants were split into two conditions:

RTEV (Equalized Training Volume): Both training frequencies (one and three times per week) had an equal total volume of weight lifted.
RTUV (Unequalized Training Volume): The three-times-per-week condition could lift more total volume than the one-time-per-week condition.

Training Schedule: The participants trained each leg with a different frequency. One leg followed a once-per-week routine (performing nine sets in one session), and the other leg followed a three-times-per-week routine (three sets per session across three sessions).

Repetition Scheme: Over the 9-week period, participants used a linear periodization model:

Weeks 1–3: 12 repetitions maximum (RM).
Weeks 4–6: 10 RM.
Weeks 7–9: 8 RM.

In the RTUV group, both the once-a-week and three-times-a-week legs did nine sets total each week. However, the leg that trained three times a week didn’t have to match the total weight lifted by the once-a-week leg. That means the three-times-a-week leg could use heavier weights during its sets across the week, leading to more total weight lifted.
In the RTEV group, both legs had to match the total amount lifted, so even if the training was spread out over three days, the average weight per set was kept the same as in the once-a-week session.

The Results?

Both training frequencies significantly increased maximal strength (1RM) and muscle size (cross-sectional area or CSA).

But when the training volume was the same across sessions (RTEV), training three times a week didn’t provide any noticeable benefits over once a week.

On the flip side, when higher frequency meant more volume (RTUV), it resulted in greater muscle growth and greater gains in strength, showing that higher volume is a primary driver of both.

That being said, it doesn’t matter much if you do all your sets for a muscle group in one weekly session or spread them out over multiple sessions.

As long as you can keep your energy up during that long session, and the quality of your training doesn’t tank, that is, which isn’t unthinkable during a 20+ set session.

Why You Should Care

This study highlights what previous research has hinted at, that cranking up your training frequency might only benefit your gains if it also boosts your total training volume.²

Otherwise, for both hypertrophy and strength, a bro-split, where you train one or max two muscle groups per workout, might stack up just as well as a split routine.

In other words, the goal of an increase in training frequency should be to be able to handle a higher training load and volume, not to spread out a certain training volume over the week.

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If you enjoyed this study write-up and want to learn more about training frequency, check out The Best Training Frequency for Muscle and Strength for a deeper dive.