What is the best indicator of improved muscular endurance?

The best indicator of improved muscular endurance is the higher number of repetitions that an individual can perform with a given weight. Muscular endurance refers to the ability of a muscle or group of muscles to sustain repeated contractions over a period of time. When a person increases the number of repetitions they can complete at a specific resistance level, it indicates that their muscles are adapting to the physical demands placed upon them, becoming more efficient and resilient.

This improvement is typically a result of various physiological adaptations, including increased stamina of the muscular fibers, enhanced blood flow, and greater efficiency in energy utilization. Therefore, the ability to perform more repetitions as a result of training is a clear sign that muscular endurance has improved.

While other options, such as increased weights lifted, reduced body fat percentage, and increased flexibility, are related to fitness and conditioning, they do not specifically measure muscular endurance. Increased weights indicate strength gains, reduced body fat is related to body composition, and flexibility pertains to the range of motion, none of which directly assess endurance capabilities.