Exercising immediately after a heavy meal, particularly one rich in fat, fried foods, or high protein, can negatively impact workouts. A doctor explains that the body struggles to manage simultaneous digestion and exercise, as blood flow shifts from the stomach to muscles. This can lead to discomfort such as bloating, cramps, nausea, and reduced energy. Experts recommend waiting two to three hours after a heavy meal before engaging in physical activity to allow for proper digestion and optimal performance.