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Informations sur les Sciences de l'Entraînement Sportif

Increase training frequency to improve strength and hypertrophy?

by P. Debraux | 25 October 2022

training, frequency, volume, strength, muscle, hypertrophy, sport, science

The main physiological adaptations to resistance training are gains in muscle strength and hypertrophy. The magnitude of the gains depends on certain training variables such as the intensity of the load, rest intervals, whether or not the training is to failure, the speed of execution, the choice and order of exercises, the range of motion, the type of contraction, the training frequency and the training volume.

Workouts frequency refers to the number of sessions performed per week, specifically the number of times a muscle group is trained. Most practitioners train with a low frequency, that is, they train each muscle group 1 to 2 times per week. Each session is devoted to 1 or 2 muscle groups, at most. This training method comes from bodybuilding and is called "Split". On the other hand, some people use sessions called "Full-Body" where all the muscle groups are trained at each session. The frequency of this type of training is therefore higher with 3 to 6 sessions per week. Nevertheless, the question of which method is best suited for gaining strength and muscle mass often arises. Many claim that the Split is an advanced method since it is the method mainly used by bodybuilders (whose objective is to maximize muscle mass) and that it would allow for better recovery.

By playing on the frequency of sessions, or at least on the frequency with which a muscle group is trained, it is the distribution of the overall training volume that also varies. Training volume is defined by the product of the number of sets, the number of repetitions and the external load. For the same volume, one study showed that an increase in the number of weekly sessions resulted in a greater increase in muscle hypertrophy, perhaps caused by more frequent stimulation of muscle protein synthesis. But increasing frequency can also mean increasing training volume. And as we discussed in a previous article, volume would seem to have a dose-response relationship with hypertrophy, with increased volume allowing for increased gains in muscle hypertrophy.

However, most of the studies are conducted by comparing the effects of different training sessions on inexperienced practitioners. Moreover, it is clearly established that there is a great deal of variability in muscular adaptations in humans. Not everyone reacts in the same way, due to their genetics, training history, diet, motivation, etc. A better way to proceed would be to choose an intra-individual comparison protocol with experienced individuals. That is, the impact of different training sessions on one of the two members of the same person should be analyzed. This approach could reduce the variability that exists in inter-individual comparison protocols.

The Study

To try bringing more relevant answers, a team of Brazilian researchers compared the impact of various frequencies of training, with equal and unequal volume, in an intra-individual way in experienced body-building practitioners. To do this, 24 young men, all of whom were experienced lifters (6.2 ± 4.2 years of training), were recruited to perform 9 weeks of unilateral inclined leg press training (45°), in which one thigh performed 1 training session per week and the other thigh performed 3 training sessions. They were divided into 2 groups of 12: one group worked with an equal weekly volume and the other group with an unequal weekly volume.

Nine sets were performed each week for both groups at 12RM during the first 3 weeks, at 10RM during weeks 4,5 and 6 and at 8RM during weeks 7,8 and 9. For the equal-volume group, the lower extremity that trained only once per week began by performing 9 sets. Relative to the total number of repetitions performed, the number of repetitions for the 3 sessions was calculated for the other lower limb. For the unequal volume group, the lower limb that trained 3 times per week was not limited by the volume achieved by the lower limb training in a single session.

The maximal force (1RM) at the inclined press was assessed for each lower limb, before and after the 9-week protocol. And thigh cross-sectional area was measured via magnetic resonance imaging (MRI) at approximately 50% of the distance between the greater trochanter and the lateral epicondyle of the femur.

Results & Analyzes

The main results of this study show that there were no significant differences in 1RM and muscle cross-sectional area between the different training frequencies, regardless of whether the total volume was equalized or not. All training conditions increased 1RM and thigh muscles hypertrophy. However, when effect size is taken into account, the results show that training with a higher frequency and without volume equalization results in better gains in 1RM and hypertrophy.

Why is taking effect size into account important? (Cliquez pour Afficher / Masquer)

While statistical significance shows that an effect exists in a study, practical significance shows that the effect is large enough to be meaningful in the real world. Statistical significance is denoted by p-values, whereas practical significance is represented by effect sizes.

Statistical significance alone can be misleading because it’s influenced by the sample size. Increasing the sample size always makes it more likely to find a statistically significant effect, no matter how small the effect truly is in the real world.

In contrast, effect sizes are independent of the sample size. Only the data is used to calculate effect sizes.

Source: https://www.scribbr.com/statistics/effect-size/

This study shows that for the same volume, no difference in gains is observed by changing the training frequency. These results are similar to those observed in other studies in experienced practitioners. However, the volume is restricted in this type of protocol, since participants are not allowed to do more than is possible in a single session. In reality, if it is possible to achieve a certain volume in a single session, it is certainly possible to achieve much more in 3 sessions. This is what the results here tend to confirm. For the group that did not equalize the total training volume, it was 137,986 ± 8,126 kg for one weekly session and 164,894 ± 12,855 kg for 3 weekly sessions, i.e. an increase in volume of about 17%.

Practical Applications

These results confirm once again that total training volume is a very important variable for muscle hypertrophy and strength. Here, intra-individual comparison avoids the risk of variability between each individual (genetics, diet, training history, motivation, etc.). Increasing the training frequency of a muscle group should therefore not be done to distribute a given volume, but to increase the total volume, if the aim is to increase strength and especially muscle mass.

Similarly, you should not be afraid to train a muscle group more frequently. If the recovery capacity is good and the necessary rest time between each session is granted, there is no reason not to do more. Nervous fatigue, which is often used as an argument against more frequent training, is not something to be feared either, if progressivity is respected.


  1. Neves RP, Vechin FC, Teixeira EL, da Silva DD, Ugrinowitsch C, Roschei H, Aihara AY and Tricoli V. Effect of different training frequencies on maximal strength performance and muscle hypertrophy in trained individuals – a within-subject design. PloS ONE 17(10) : e0276154, 2022.

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