Need another reason to exercise? According to a study featured on Science Daily, physical activity may help reduce anxiety caused by stress.

Researchers from Princeton University experimented with two groups of mice. One group was provided access to a running wheel, while the other wasn't. Those with the running wheel ran as much as four kilometers a night, while the other group remained sedentary. After six weeks, both groups were briefly exposed to cold water.

The sedentary group immediately showed an increase in brain activity, with neurons rapidly firing to sustain an anxious, excited state in response to the stressor. On the other hand, the group who had been able to exercise didn't show immediate anxiety. Researchers believe that neurons of the active mice produced more of the neurotransmitter gamma-aminobutyric acids (GABA), a certain type of neurotransmitters that helps keep anxiety under control.

So if you're regularly stressed out, find time for a workout session. Aside from lowering your cholesterol levels and lessening your risk of becoming overweight, exercise could also help you get a better control over your anxieties.

(Photo by lululemon athletica via Flickr Creative Commons)