When lifting light weights until exhaustion, the body predominantly engages fast-twitch muscle fibers, resulting in heightened metabolic stress and improved muscular endurance. Conversely, lifting heavy weights primarily activates slow-twitch muscle fibers, generating greater mechanical tension and muscle fiber breakdown. The body undergoes repair and reconstruction of these fibers, culminating in enhanced muscle size and strength. Varied muscle fiber recruitment yields distinct adaptations: light weightlifting enhances explosive power and speed, whereas heavy weightlifting promotes muscle hypertrophy and strength gains. #shorts #3danimation #workout #muscle