Anaerobic stretching is different than your everyday warm-up stretches; they differ in intensity and duration. Stretching out key muscles such as calves, thighs, and hamstrings is important, and anaerobic stretching does this and prepares your muscles in an active way. Knee-to-chest lifts, high jumps, and light jogging or running in place are all forms of anaerobic stretching. Stretching like this will increase your blood circulation, get your heart prepared for the long run ahead, and will alert your body that it is time to prepare to process glucose, turning it into energy. Anaerobic stretching is the ultimate power-warmup. It can also help prevent loss of energy, and reduce your risk of injury during your run.