Impairment of what process can occur in highly active individuals due to energy deficits?

In highly active individuals, energy deficits can significantly impair the resynthesis of muscle glycogen. Glycogen is the stored form of glucose found in muscles and the liver, serving as a critical energy source during prolonged or intense physical activity. When an individual engages in rigorous exercise without consuming enough calories to meet their energy expenditure, the body lacks the necessary resources to restore glycogen levels effectively.

This impairment can lead to decreased performance, increased fatigue, and diminished recovery times, as the muscles are unable to replenish their essential glycogen stores. Without adequate glycogen, athletes may experience reduced capacity for sustained high-intensity exercise, which in turn can affect overall training results and athletic performance.

While protein synthesis, fat oxidation, and bone density are also important processes that could be influenced by overall energy availability, the specific concern in this context is the resynthesis of muscle glycogen, which is directly affected by the availability of energy after intense training.