Air pollution can cut exercise benefits in half, major global study warns
Long-term exposure to high levels of air pollution can significantly reduce the health benefits of regular exercise, a new global study has found. The protective effects of physical activity drop sharply when PM2.5 levels exceed 25 μg/m³.
New Delhi: Regular exercise can greatly undermine the health benefits of long-term exposure to toxic air, a new international study by researchers at University College London (UCL) found. The study, which was published in BMC Medicine, involved analysis of data of over 1.5 million adults that were being followed up in multiple countries over a period of more than 10 years. Although the exercise continues to reduce the risk of death, the protective value decreases significantly in the regions with high air pollution, published in the journal BMC Medicine.
Scientists focused on PM2.5 minute air particles that may infiltrate deep into the lungs and blood. They discovered that after yearly average levels of PM 2.5 reached 25 micrograms per cubic metre and above, the positive effects of regular exercise activity declined significantly. Almost half of the world population resides in areas with a value above this threshold.
Exercise helps, but pollution weakens its impact
On the whole, there was a 30 per cent lower risk of death in adults who achieved at least two and a half hours of moderate or vigorous physical activity per week. This only dropped to 12-15 per cent in areas with high pollution. The protective effect died off further at PM2.5 over 35 μg/m³ and cancer-related deaths.
The researchers emphasised that exercise was not something to be discouraged. Rather, they advised air quality indexes, choosing to use cleaner routes, or reducing the intensity of the workout on a given polluted day. They have observed that, on average, UK respondents were in less polluted settings, but winter peaks frequently exceeded the problematic 25 μg/m³ level.
Global findings, local implications
The group has aggregated information on seven large studies, three of which have never been released before. They also presented the consideration of very broad variables like income, education, smoking habits, and existing health conditions. Nevertheless, they had to admit that the data were limited, and they were not available in low-income countries, where the pollution levels tend to be much greater.
Scientists reiterated that healthy ageing requires clean air and physical exercise. They encouraged more vigour to decrease pollution in the world so that the humans can have the maximum advantages of exercise.