Sleep is an important factor for muscular endurance, especially considering the prevalence of sleep deprivation due to athletes’ traveling schedules, time zone changes, and insomnia before competition. A recent meta-analysis concluded that acute sleep loss (less than 6 hours of sleep) reduces strength endurance (i.e., ≥2 resistance reps or >5s sustained contraction) by 10%.[1]
There is a general decline of muscular endurance with age, though this can be mediated by appropriate training regimens.[2] There are also generally differences in muscular endurance by sex.[3]