Going for a run even better than first thought

THE benefits of going for a run to alleviate stress after a tough day in the office are well known, but a study has now discovered why working up a sweat is so relaxing and mood-boosting.

Exercise actually removes harmful chemicals from the body and can tackle depression, researchers at the Karolinska Institute in Sweden found. Physical activity purges the blood of a substance which accumulates during stress and can be harmful to the brain, the report says.

Previous studies had suggested people felt positive after exercise as it released endorphins in the brain. But it now appears that during exercise, the muscles begin to act like the liver or kidneys and produce an enzyme which clears out a molecule linked to depression.

The research team is hopeful that eventually a pill could be produced which would trigger the same effect to help with mental illness.

"Our initial research hypothesis was that trained muscle would produce a substance with beneficial effects on the brain," said study leader Dr Jorge Ruas. "We found the opposite: well-trained muscle produces an enzyme that purges the body of harmful substances. So the function is reminiscent of the kidney or the liver."

Dr Ruas said cardiovascular exercise would probably be best to reduce stress. "It is possible that other kinds of exercise will also have an effect, like resistance training such as weight lifting," he said. "But our results support the use of aerobic exercise like biking and running."

The study was published in the journal Cell. – The Daily Telegraph