Aerobic Exercise

form of Exercise that involves or improves oxygen consumption by the body. Aerobic means "with oxygen", and refers to the use of oxygen in the body's metabolic or energy-generating process. Many types of exercise are aerobic, and by definition are performed at moderate levels of intensity for extended periods of time. http://en.wikipedia.org/wiki/Aerobic_exercise

Running, swimming, etc.

Many people whether it's really the right path to Physical Fitness.