Leading a sedentary lifestyle leads to muscle atrophy. It is the medical term that describes the process of your muscles wasting away. When your muscles aren’t exercised to their full capacity, they begin to break down.
When your body begins to lose muscle, your metabolism slows and you begin to gain weight. Increased body fat eats away at testosterone, and it can be a vicious cycle. Low testosterone causes depression, lethargy, and fatigue that can keep you from exercising to lose fat and build muscle.