What is one consequence of not applying the principle of overload in training?

The principle of overload is fundamental to physical training, as it requires that the body be subjected to more stress than it is used to in order to induce adaptations and improvements in strength, endurance, and other fitness components. When this principle is not applied, there is insufficient stimulus for the body to adapt, which results in stagnation.

Without adequate overload, the body remains in its current state, leading to no meaningful gains in fitness levels. This is why a lack of overload ultimately prevents progress; to improve, athletes and individuals engaging in exercise must progressively increase the intensity, duration, or frequency of their workouts to challenge the body.

While other options center around potential benefits like reduced injury risk, enhanced recovery, or increased energy levels, these do not directly connect with the concept of adaptation and progress in fitness that overload directly influences. Therefore, the absence of overload will specifically lead to a lack of improvement in fitness levels, making that answer the most accurate in this context.