Should Londoners Think Twice Before Exercising Outside?

Bad news for London's outdoor runners and fitness fanatics. Mayor Sadiq Khan has issued a warning against "physical exertion" because of the "shameful state" of toxic air in the capital. Khan tweeted yesterday that everyone – even "the physically fit" – may need to reduce the amount of exercise they do outside because London is currently on a "very high" pollution alert under his new air quality warning system. This is the first time this alert, the highest and most serious, has been issued. Khan urged car, van and lorry users to "avoid idling" and turn their engines off if stationary for more than a minute to cut pollution. He said his proposals to improve air quality are "the boldest of any city in the world". The Mayor's plans include introducing the world's first Ultra Low Emission Zone (ULEZ) in 2020 (or 2019, if this earlier date is confirmed), in which "only the newest, cleanest diesel vehicles will be allowed to drive".

An age limit on London taxis has also been implemented, which has removed 6,000 of the oldest and most polluting vehicles from the roads, and there has been an investment into reducing pollution from buses. Khan has previously said that "tackling London’s filthy air" is one of his main priorities as mayor, but any progress will be gradual. So, if you're an outdoor runner or regularly walk long distances around the capital – especially if you experience symptoms such as a cough or sore throat – it might be worth considering working out indoors or using public transport to get around for the time being. High and very high levels of pollution can cause asthma sufferers to need their inhaler more and can increase the risk of respiratory diseases, including asthma and lung cancer. However, it won't be possible for everyone to modify their routine and many people training for the London Marathon are understandably frustrated by the warning, with some suggesting the Mayor should go further to cut pollution.

Khan's warning against exercising outdoors comes just weeks after a south London street breached its 2017 air pollution limit in just five days. Brixton Road in Lambeth exceeded the World Health Organisation's pollution guidelines 19 times by 9pm on Thursday 5th January, according to monitoring from the London Air Project at King's College. There is, however, one minor plus side to the current scary level of pollution in the capital, albeit bittersweet. Londoners have reported seeing exceedingly pretty pink-red sunsets which, according to science, are caused by sunlight interacting with molecules in the air, primarily nitrogen and oxygen.

Nevertheless, as aesthetically pleasing as our polluted sky may be, we'd prefer air that doesn't damage our health or prevent us from living our normal lives.