When it comes to the topic of strength training, it is often the case that different indicators are discussed. These indicators include the number of repetitions, the number of training sessions or the “ideal” training weight.

What is often missing from this discussion, however, is how long a repetition or a training set should last.

Stress time: key to target muscle development

This so-called “stress time” is absolutely crucial for the development of target muscles. Current sports science research suggests that the exercise time on the target muscle should be between 60 and 120 seconds during intensive training. This means that the target muscle is strained to absolute capacity. Ideally, you should design an exercise regime to last at least 60 seconds but less than 120 seconds, using a suitable training weight or appropriate fitness exercise adapted to your individual fitness level.

Track your performance development

For this reason, I recommend that you use a stopwatch during training to check if the exercise time is in the ideal target range of 60 – 120 seconds. If you are progressing to a stress time that lasts longer than 120 seconds, then increase your training weight or seek a more challenging exercise. Personally, when I train on my own, I write down my respective stress times for my exercises, so I have my performance development in mind.

Stress time is key 

It is also important to keep in mind the repetition figures, in relation to stress time.

Take for example, bench pressing. Say that you have chosen the training weight so that you can perform a stress time of 60 seconds. 

As long as the stress time is identical, then the order of repetitions does not matter. For example, you can choose any of the following options within 60 seconds: