Few can deny how much better a person feels after a workout.  Sure individual joints might be creaky or muscles a little tight, but overall there is often a sense of well-being that follows a good workout.  Physiologically, your body releases huge amounts of chemicals called "endorphins" and "encephalins."  These chemicals are your body's natural pain relievers and there is some evidence that they can affect mood. 

Here is an article I came across from Duke University talking about the relationship between exercise and depression.  In the study, it was found that general exercise may, in fact, be more effective at treating depression than prescription antidepressants!   So I guess the take home message would be:  If you feel depressed, maybe it's a good time to get some exercise!

EXERCISE CAN HELP DEPRESSION 

"Durham, N.C. -- Researchers at Duke University Medical Center have found that exercise can be a viable alternative to medication in treating major depression. One hundred fifty-six patients diagnosed with major depressive disorder were assigned to three groups. One group received only medi-cation, another only exercise, and a third a combination of exercise and medication. After 16 weeks, all three groups showed significant and similar improvement. Psychologist James Blumenthal says many of the patients say they felt they were finally taking an active part in their treatment.

"When they begin an exercise program, they accomplish far more than they thought they would and could and they feel better about themselves. This sense of mastery and accomplish-ment may very well be at least partly responsible for the kinds of benefits that they achieved in terms of reducing their depression and feeling better."

Blumenthal says some members of the group given medication and exercise complained that the medication actually hampered their ability to exercise.

Blumenthal says researchers are now recruiting patients for a new study that starts in July, one that will try to determine whether it was the exercise itself or the supportive environment of the gym that caused the improvement in symptoms of depression.

"We did find that the exercise was very, very effective, but the exercise occurred in a context of this group support and it was really a very supportive environment. And the extent to which it was the exercise that was responsible for the changes or whether it was the group support or a combination of both, we hope to tease out those elements in our future work."

For more information, contact: Cabell Smith, Office of News and Communications | (919) 681-8067 | cabell.smith@duke.edu"

Source:  Duke University's News and Communication

http://www.dukenews.duke.edu/2000/06/mm_exercisecan.html