According to a new study, varied strength training has a positive effect on strength development, but not on muscle growth.

For years, the word around gyms has been that to build muscle you need to vary your training in terms of weights, reps, and exercises.

“…periodized strength training is conducive to building strength, but not muscle mass.”

But the new findings show that so-called “periodized strength training” – where training varies according to increasing and decreasing variables such as the amount of weight lifted, as well as the number of repetitions – benefits the strength development.

“The study establishes that periodized strength training is conducive to the development of strength, but not muscle mass. If one wants to get stronger, it is important to vary his training,” says Jesper Lundbye-Jensen , associate professor in the Department of Nutrition, Exercise and Sport at the University of Copenhagen and last author of the article in Sports medicine.

The answer to why periodized strength training can help build strength, but not muscle mass, likely lies in our nervous system, researchers say.

“While people get stronger with periodized training compared to non-periodized training, this is likely because strength training also trains the nervous system, and therefore our ability to coordinate and activate muscles to the maximum. “, Lundbye-Jensen said.

Increasing muscle mass through strength training requires training until fatigue sets in and spending a sufficient number of hours in the gym to do so, says first author Lukas Moesgaard.

“Research suggests that strength training especially leads to muscle growth when training muscle to exhaustion. And, as a general rule, more exercise leads to more muscle growth,” he explains. he.

In the study, the researchers were also able to see that those who already exercised regularly improved their strength more by varying the intensity of their weekly training and alternating between heavy and light lifting exercises.

Untrained people, on the other hand, received the same benefit from training whether the variation took place on a daily or weekly basis, or whether the training was adjusted linearly – i.e. by increasing loads as an individual gains strength – over a period of time. extended period of time.

“Overall, the study demonstrates that varying the weight load and number of repetitions of strength training can help if one wants to get stronger, and that the variation should probably happen more often. when one is trained than if one is untrained. However, our results also demonstrate that varying loads and the number of reps do not appear to affect the amount of muscle growth,” Moesgaard says.

The article is based on a scientific study known as a systematic review with meta-analysis, where researchers collect and review all relevant scientific literature in a given field.

Source: University of Copenhagen