The repetition maximum, often abbreviated to 1RM, is the highest weight that can be lifted for exactly one technically clean repetition of a given exercise. Besides the one-rep max there are also multi-rep maxima, such as the five-rep or ten-rep maximum, that is, the weight that is possible for exactly five or ten repetitions. In training planning, these values often serve as a reference so that training weights can be given as a percentage of the maximum, for example for sets in the range of 70 to 85 percent of the one-rep max.
A true one-rep max test is physically very demanding and carries a higher risk of injury if technique is poor, which is why it is usually recommended only to experienced trainees. In practice, the maximum is often estimated instead from a lighter multi-rep maximum using formulas.
Relevance for training and nutrition
For training planning, the repetition maximum serves mainly as a reference to control intensity in a traceable way and to make progress visible over weeks, for example as part of progressive overload. For nutrition, the value itself has no direct significance, but it does indirectly: anyone who regularly trains close to their own maximum benefits from adequate energy intake and recovery, so that the high load does not have a negative effect on technique and injury risk.