Read this article at the clinic while waiting for my turn to see the doctor. This article has reinforced my thought that exercise will help to rejuvenate ourselves whenever we are feeling down or exhausted, especially after a day of hard work or study.

Appended below are some extracts from this 'The exercise effect' article by Kirsten Weir from Monitor on Psychology Dec 2011 issue.

"Failing to exercise when you feel bad is like explicity not taking an aspirin when your head hurts." - Michael Otto, Boston University

Researchers are still working out the details of that action: how much exercise is needed, what mechanisms are behind the boost exercise brings, and why - despite all the benefits of physical activity-it's so hard to go for that morning jog. But as evidence piles up, the exercise-mental health connection is becoming impossible to ignore.

Mood Enhancement

If you've ever gone for a run after a stressful day, chances are you felt better afterward.....Research shows that exercise can also help alleviate long-term depression...Subjects who reported regular exercise had lower depression scores than did their less active counterparts..."Exercise seems not only important for treating depression, but also in preventing relapse."

Fight-or-Flight

Researchers have also explored exercise as a tool for treating - and perhaps preventing - anxiety. When we're spooked or threathened, our nervous systems jump into action, setting off a cascade of reactions such as sweating, dizziness, and a racing heart. People with heightened sensitivity to anxiety respond to those sensations with fear.

Smits and Otto reasoned that regular workouts might help people prone to anxiety become less likely to panic when they experience those fight-or-flight sensations. After all, the body produces many of the same physical reations-heavy perspiration, increased heart rate - in response to exercise. They tested this theory... "Exercise in many ways is like exposure treatment," says Smits. "People learn to associate the symptoms with safety instead of danger."

Buffering the Brain

It's also unclear exactly how moving your muscles can have such a significant effect on mental health...Some reseachers suspect exercise alleviates chronic depression by increasing scrotonin (the neurotransitter targetted by antidepressants) or brain-derived neurotrophic factor. Another theory suggest exercise helps by normalizing sleep, which is known to have protective effects on the brain.

There are psychological explanations too. Exercise may boost a depressed person's outlook by helping him return to meaningful activity and providing a sense of accomplishment.

Those who think they have no time for bodily exercise will sooner or later have to find time for illness. - Edward Stanley

Let's  exercise now!

Source: http://www.nxtbook.com/nxtbooks/apa/monitor_201112/index.php?startid=51#/56