Jogging outside could make you stupid – and more likely to suffer mental health problems
Exercising in busy, traffic-filled areas could actually cause mental declineCity joggers' brains less able to store new knowledgeAnd have higher levels inflammation, linked to mental decline
10:38 GMT, 11 December 2012
People who exercise in urban areas have higher levels of mental decline and inflammation in the brain
It has long been hailed as beneficial to both body and mind – and if nothing else, a form of stress release after a hard day at the office.
But new research suggests exercising outside could do more harm than good when it comes to your brain.
For jogging in busy, traffic-filled areas could actually cause mental decline.
Belgian researchers have found that people who live in a city and exercise outdoors have higher levels of inflammation and lower scores on cognitive tests than those who exercise outside in the suburbs.
In a study, they separated exercisers into two groups who exercised three times a week for 12 weeks, between midday and 1pm. One group alternated and walking in a busy, urban area – the other in a rural location.
The researchers, from Vrije Universiteit Brussel, then gave the subjects a test to measure their response time and attention span.
They found that high levels of air pollution in the city prevented participants from getting some of the brain-boosting benefits of exercise, such as the ability to absorb new information and a reduced chance of mental health problems.
The city joggers also had significantly higher blood levels of some inflammation markers, Men's Health magazine reported.
This is important because inflammation in the brain is associated with mental illness.
Last month, U.S. research found that
higher level of air pollution in towns and cities is ageing the brains
of over-50s by up to three years..
Those who jogged in busy, traffic fillled areas had brains less able to cope with absorbing new information
Scientists have found that exposure to higher levels of air pollution can lead to decreased brain power in over-50s.
In a study of almost 15,000 older adults, researchers at the US-based National Institute on Aging found fine air particulate matter may be an important environmental risk factor for reduced thought power.
Air pollution is already estimated to reduce the life expectancy of everyone in the UK by an average of seven to eight months, probably by affecting the heart and lungs.
But the new findings aren't an excuse not to exercise, said lead researcher Romain Meeusen, head of the department of Human Physiology and Sports Medicine at the university.
In fact, he says it's actually better to drag yourself out in the wind and rain, as these climates blow the fine particles away so you're not left inhaling them.
He also recommends avoiding exercising in rush hour – the more cars, the more pollution from exhaust fumes – and exercise in a park, whenever possible.