* strengthens self-confidence and a sense of personal worth
* increases a capacity for work so that you feel less tired at the end of the day
* diminishes smoking, drinking, and other unhealthy habits
* helps those with eating disorders—who either are overweight or dangerously underweight—change their eating habits
* lessens or lifts depression
* improves relationships that were destructive or motivates people to separate
* reduces or eliminates confused and irrational thought processes in some schizophrenic patients
Treating Depression
In particular, running as described here appears to be especially effective in treating depression: "... it's hard to run and feel sorry for yourself at the same time."[[1]] Running tends to increase your sense of independence and self-confidence, which have been weakened if you have been depressed. Psychotherapy and drug therapy, in contrast, may encourage dependency on the therapist or psychiatrist.
[[1]] James Fixx, The Complete Book of Running (New York: Random House, 1977), p. 16.