At what point should an individual consider increasing their exercise load?

Increasing exercise load is most appropriately considered when an individual starts to plateau in performance. This plateau indicates that the body has adapted to the current exercise regimen, and to continue making progress, it is essential to introduce a new challenge. By increasing the load, either through resistance, duration, or intensity of workouts, the individual can stimulate further physiological adaptations and improvements in strength, endurance, and overall fitness.

The other options do not provide a thoughtful basis for increasing exercise. For instance, feeling sore after every workout can be a sign of inadequate recovery or overtraining, suggesting instead a need to evaluate the current routine rather than increase the intensity. Not being able to see one's reflection is unrelated to fitness progression and could reflect issues unrelated to exercise. Lastly, reacting to the actions of others, such as friends or peers increasing their weights, may not align with an individual's specific fitness level, goals, or capability, making it an unreliable motivator for personal exercise adjustments.