Interval training can significantly enhance fitness levels by alternating between high-intensity efforts and lower-intensity recovery periods. This approach boosts metabolic rate, leading to greater calorie expenditure both during and after workouts, a phenomenon known as the afterburn effect. Interval training can improve cardiovascular fitness more efficiently compared to steady-state workouts, often leading to increased endurance and strength gains. It can be adapted for various fitness levels, making it a versatile option for achieving fitness goals.