repetition maximum

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The maximum load that a muscle group can lift over a given number of repetitions before becoming fatigued. For example, a 10-RM load is the maximum load that can be lifted over 10 repetitions.

The maximum load that a muscle group can overcome for a given number of repetitions before fatigue prevents further muscle action. The 10 RM, for example. is the maximum load that can be overcome for 10 repetitions.