One of the best ways to train your muscles is to do extreme weight training. The key is to exercise such power that your heart rate starts to go up significantly while your body temperature rises with it. Your pace of breathing will go up. The benefits are an increased amount of human growth hormone production.
Now there are two exercises in particular that caught my attention.
The first one is to train your abdomen muscles. This is called the plank. Hold this position for an extended amount of time.
The second one is to train your legs and buttocks. This is called a lunge. Hold this position for an extended amount of time.
Remember, hold the position until you feel your heart rate is significantly higher.