This is an excerpt from Functional Core for Women by Kia Williams.
Muscular endurance is the ability of a muscle to repeatedly exert force, perform multiple repetitions of an exercise, and remain active over an extended period. Think of it as running a marathon rather than a sprint. Typically, endurance-focused training is performed with less resistance, less weight, or body-weight only in order to sustain the exercises for a longer period before muscular fatigue or failure. The goal is to perform quality movement patterns for higher repetitions. Compromise of form is a sign to end the exercise set and rest before continuing to the next set.
Workout 1: Abs With Focus on Muscular Endurance
Workout period: 20 to 30 minutes
Number of exercises per workout sequence: 4 or 5 exercises
Sets: 2 or 3 sets for each exercise; rest periods of 30 seconds or less between each set of each exercise
Reps: At least 12 reps per set or per your personal preference
Resistance: Body weight or your definition of lighter resistance bands or weights; in other words, weight under 65 percent of your one-repetition maximum (1RM; the maximum weight you can lift for only one repetition with optimal and proper form and alignment)