Meaning: This rule suggests that eating is not a mandatory part of a workout routine unless there's a specific physiological need (e.g., extreme hunger, prolonged or intense activity).
Mechanics: For moderate workouts, the body can typically use stored energy. Eating immediately before can cause digestive discomfort, and eating immediately after might not be necessary if energy levels are stable. However, for endurance or strength training, pre- and post-workout nutrition can be crucial for performance and recovery.