Complex carbohydrates support sustained energy release by providing a steady source of glucose for the body. Unlike simple carbohydrates, which can cause rapid spikes in blood sugar levels, complex carbs are digested more slowly due to their intricate structures and fiber content. Foods such as whole grains, legumes, and vegetables release energy gradually, helping to maintain stable energy levels and reduce fatigue during physical activity. This makes complex carbohydrates essential for athletes and individuals engaged in prolonged exercise, as they support endurance and performance without causing energy crashes.