What are the characteristics of effective exercise?

The effect of a wide range of physical activities and sports has been investigated. Various forms of cardiovascular exercise including running, walking, aerobic dance, and circuit training are most common in studies. All of these activities have indicated that they can be effective in improving self-perceptions, although there is a reflection of the general finding that only approximately 50% produce significant change. Studies with other activities such as swimming, flexibility training, martial arts, and expressive dance have generally failed to indicate significant change, however they are too few in number to make firm conclusions. Many of these studies have been conducted on college-age males and females, a population prone to non-significant results. Where endurance exercise and walking has been used with middle-aged adults, there is more conclusive evidence of success than with younger adults.