During intense physical activity, nutrients such as glycogen (stored carbohydrates), electrolytes, and certain vitamins and minerals may become depleted. Glycogen stores are the primary energy source for high-intensity workouts, and prolonged exertion can lead to its significant depletion. Electrolytes, including sodium, potassium, and magnesium, are lost through sweat and are vital for maintaining fluid balance and muscle function. Vitamins B and C may also be depleted due to increased metabolic activity. Replenishing these nutrients through diet and hydration is crucial for recovery and performance maintenance.