Fat vs. Muscle: What’s the Difference? Muscle helps support your joints, protect your spine, and absorb impact when you move. Strong muscles around the knees, hips, and back help keep the body aligned and reduce strain during daily activities like walking, lifting, and standing. Fat plays an important role in energy storage and hormone balance, but it doesn’t provide support or stability to joints. When muscles are weak, more stress is placed on bones and joints, which can contribute to discomfo