Your body is a never-ending construction project. As you read this, old cells in your bones are being broken down and replaced by new ones. Neurons in your brain are making new connections based on information taken in by your senses. Your hair is growing, new skin cells are surfacing. Nature's regenerative processes are amazing, but remember: You are the foreman of this construction project. The right combination of aerobic and anaerobic exercise will help build a better you.