Training frequency per week: what the research says

Once a week 'all out' or several times with less volume? The question of training frequency has for decades divided athletes into supporters of classic splits and full-body training. The editorial team examined meta-analyses on the effect of frequency on hypertrophy and strength and explains how to choose a scheme that fits your schedule and recovery capacity.

What frequency is in question

When people talk about training frequency, two concepts are often mixed up: how many times a week a person goes to the gym and how many times a week a specific muscle group is trained. For hypertrophy and strength it is precisely the latter that matters. A person can train six days a week on a split program where each muscle works only once, or three times a week on a 'whole body' scheme where each group is loaded three times.

The classic bodybuilding split, popular since the 1980s-1990s, involved training each group once a week with a large volume per session. Alternative schemes - 'upper-lower,' 'push-pull-legs' twice a week, or full-body - distribute the load more often.

The physiological basis of the debate is the duration of elevated muscle protein synthesis after a workout. The classic work by MacDougall et al. (1995) showed that after a heavy strength load protein synthesis remained elevated for approximately 36 hours. Hence the hypothesis: if a muscle is trained more often, the 'windows' of anabolism will be more frequent.

However, reality is more complex. In untrained people the response lasts longer, and in trained ones shorter, and it is affected by muscle damage, nutrition and overall volume. So the answer should be sought not in theoretical calculations but in training studies.

Frequency and hypertrophy: meta-analyses

The meta-analysis by Schoenfeld, Ogborn and Krieger (2016) showed that training a muscle group twice a week produces a greater gain in muscle mass than once. However, in most of the studies included in this analysis volume was not equal: more frequent training often also meant more sets.

A later analysis by the same authors (Schoenfeld, Grgic, Krieger, 2019) specifically separated studies with equal and unequal volume. The conclusion: when volume is equalized, frequency does not significantly affect hypertrophy. That is, the main thing is the total number of quality sets per week, and frequency is only a way to distribute them.

The practical significance of this conclusion is great: there is no 'magic' frequency. If it is convenient for an athlete to train each group once a week and they perform sufficient volume with quality, the result will be similar. But if the weekly volume is large, splitting it into 2-3 sessions is usually easier than doing it all at once.

The reason is simple: the last sets in a long workout of one group are performed against a background of severe fatigue and are probably of lower quality. Distributing the volume helps to preserve the high quality of each set.

Frequency and strength

For strength the picture is somewhat different. The meta-analysis by Grgic et al. (2018) showed that higher training frequency is associated with a greater gain in strength, but this advantage largely disappeared when volume was equalized. At the same time, for multi-joint exercises and for trained participants, more frequent training had certain advantages.

The explanation is related to the skill-based nature of strength. Squats, bench press or deadlift are technical movements, and performing them more often with moderate fatigue helps to refine coordination. That is why in powerlifting programs with the main exercises performed 2-4 times a week are common.

In contrast, for isolation exercises, where the technical component is smaller, frequency matters less. Here again volume plays the main role.

For an athlete combining goals of strength and hypertrophy, a reasonable compromise is to perform the main exercises at least twice a week and to distribute the auxiliary ones as is more convenient.

How to choose frequency for your schedule

The best frequency is the one a person actually adheres to. Studies standardize conditions, but in life schedule, work, sleep and family obligations matter more. A six-day program that an athlete skips half of will produce less than three stable workouts.

For beginners, full-body 2-3 times a week is most often recommended: they repeat the basic movements more often, master technique faster, and a small volume per session does not overload them.

With experience, when weekly volume grows, it is more convenient to switch to 'upper-lower' or push-pull-legs schemes so that each workout does not last more than an hour and a half to two hours.

It is also important to consider other loads: running, team sports, physical work. They reduce the resource for recovery, and the frequency of strength training will have to be adjusted accordingly.

Recovery and the limits of frequency

More frequent training requires better recovery. If a muscle is trained three times a week, each session should be more moderate in volume and perhaps come a little less close to failure. Otherwise accumulated fatigue will negate the advantages of a more frequent stimulus.

Guidelines for assessing recovery are the absence of pronounced soreness before the next workout of the same group, stable or increasing strength, normal sleep and motivation. If these indicators worsen, frequency or volume should be reduced.

• do not train one group hard two days in a row;
• distribute heavy and lighter workouts across the week;
• monitor sleep and protein intake;
• plan deload weeks;
• account for non-sport loads.

Finally, remember tendons and joints: high-frequency programs with the same exercises can overload the same structures. Varying exercises and grips helps to distribute the load.

We also recommend reading our materials on the number of sets per muscle group, on periodization and on warming up before strength training.

Editorial conclusions

At equal weekly volume, the frequency of training a muscle group does not significantly affect hypertrophy. The main thing is the number of quality sets, and frequency is a convenient way to distribute them.

For strength in multi-joint exercises, more frequent training (2-3 times a week) may have a certain advantage thanks to refining the movement skill.

For most athletes it is rational to train each group about twice a week, but the final choice should take into account schedule, recovery and personal preferences.

References

1. Schoenfeld BJ, Ogborn D, Krieger JW. Effects of resistance training frequency on measures of muscle hypertrophy: a systematic review and meta-analysis. Sports Med. 2016;46(11):1689–1697.
2. Schoenfeld BJ, Grgic J, Krieger J. 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. J Sports Sci. 2019;37(11):1286–1295.
3. Grgic J, Schoenfeld BJ, Davies TB, et al. Effect of resistance training frequency on gains in muscular strength: a systematic review and meta-analysis. Sports Med. 2018;48(5):1207–1220.
4. MacDougall JD, Gibala MJ, Tarnopolsky MA, et al. The time course for elevated muscle protein synthesis following heavy resistance exercise. Can J Appl Physiol. 1995;20(4):480–486.
5. Damas F, Phillips SM, Libardi CA, et al. Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage. J Physiol. 2016;594(18):5209–5222.
6. American College of Sports Medicine. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687–708.