International Sports Sciences Association (ISSA) Trainer Practice Exam

What percentage of 1RM is most effective for training muscular endurance?

1. 45% to 55%

2. 55% to 65%

3. 65% to 75%

4. 75% to 85%

The correct answer is: 55% to 65%

The most effective percentage of one's one-repetition maximum (1RM) for training muscular endurance falls within the range of 55% to 65%. This range allows individuals to perform a higher number of repetitions, typically around 12 to 20, which is ideal for improving muscular endurance. Training at this intensity produces sufficient muscular stress while still permitting a greater volume of work to be completed. This volume is critical in developing the muscle's ability to sustain prolonged exercise, enhancing both the local muscular endurance and overall stamina. By leveraging this percentage, athletes can condition their muscles to perform repetitive movements more effectively, thus facilitating better performance during activities that require endurance. Choosing a higher percentage of 1RM, such as those associated with the options above 65%, may lead to strength gains but is less effective for specifically enhancing muscular endurance due to the lower number of repetitions that can be performed. Likewise, lower percentages typically result in insufficient resistance to provoke substantial endurance adaptations. Therefore, the 55% to 65% range strikes an optimal balance for achieving the desired outcomes in muscular endurance training.