If you want to improve your muscular endurance, what is the best plan?
low resistance with high reps
high resistance with low reps
low resistance with low reps
high resistance with high reps

The correct answer is low resistance and high reps.

Explanation:

Endurance should be something, which one could do for a prolonged time duration, however, not a lot of pressure or weight accompanying it. Thus, if one desires to run, and wants to do it for some time being, then it is obvious that one would want it with low resistance and high repetitions, it is basically because one would want to do something easier so one could maintain a pace and can perform it for a lengthened time duration.