To achieve a lean, athletic physique, it's important to train both type I (slow-twitch) and type II (fast-twitch) muscle fibers. Slow-twitch fibers support endurance activities, while fast-twitch fibers are responsible for power and explosive movements. Many exercisers mistakenly train only one fiber type, neglecting the full potential of their muscle mass. Incorporating both higher-rep endurance work and lower-rep, high-intensity strength training will help you develop lean muscle, increase metabolism, and burn fat more efficiently. Ready to take your workouts to the next level by targeting both fiber types?