Muscular endurance

Muscular endurance is how long a muscle can keep working before force falls away — how many press-ups you can do, how long you can hold a plank, how many times you can repeat a submaximal effort. It is distinct from maximal strength, which is about a single best effort, and from cardiovascular endurance, which is about the whole system's ability to deliver oxygen.

It matters because most everyday and sporting demands are repeated submaximal efforts rather than one-off maximums. It also underpins work capacity in the gym: better local endurance means you recover between sets faster and can handle more useful volume.

In practice it is trained with higher reps and shorter rests, and it improves through local adaptations — more capillaries, more mitochondria and better buffering of the metabolites that accumulate during hard work.