From Ergo Log
Can you choose between walking in a built-up area and walking in green surroundings? If so, choose for the latter. According to researchers at Nippon Medical School in Japan it’s demonstrably healthier.
More and more studies are showing the people function better in an environment with plants and trees. On top of that there’s not doubt that physical exercise is healthy. The researchers wanted to know what happens if you combine these two factors: green surroundings and exercise.
The researchers got 16 men, average age 57, to walk on two separate occasions. On one occasion they walked for two hours through an urban part of Tokyo, where there are almost no trees; on the other occasion they walked for two hours through a park with lots of trees. The subjects expended a similar amount of energy on both walks.
The researchers noticed that after walking in the park the men’s diastolic and systolic blood pressure was significantly lower. After walking in the built-up area this was not the case.
Moreover, after the walk in the park them men’s concentrations of the stress hormone noradrenalin and the neurotransmitter dopamine were also lower. After walking in the built-up area this was not so. In addition, the walk in the park boosted the emission of adiponectin and walking in a built-up area did not. Adiponectin boosts sensitivity to insulin. This hormone helps muscles to absorb more energy from the bloodstream.
It’s possible that natural surroundings reduce psychological stress more than urban surroundings do. Reducing stress reinforces the positive effects of exercise.
The researchers suspect that the stress-reducing effects of exercise in green surroundings are partly due to phytoncides. This is a group of compounds, such as alpha-pinene, beta-pinene, tricyclene, camphene and limonene, which trees emit to protect themselves against micro-organisms. The Japanese have shown in earlier studies that inhaling these substances reduces the production of stress hormones.
Eur J Appl Physiol. 2011 Nov;111(11):2845-53.