An expert has warned people not to wear face masks while they exercise saying that it could be highly dangerous for your health.
Currently all gyms and outdoor exercise equipment in England remains closed off because of coronavirus restrictions.
But people are still exercising at home and some forms of exercise are allowed – such as running and cycling.
But Lindsay Bottoms, a reader in Exercise and Health Physiology at the University of Hertfordshire, writing for The Conversation, said: “As you move from moderate to heavy exercise, you may be re-breathing carbon dioxide, which can reduce cognitive function and increase breathing rate.
“There may also be less oxygen in the recycled air, which could imitate exercising at higher altitudes.”
Two boys in China recently died during physical education exams while wearing face masks.
Ms Bottoms said: “Autopsies have not been performed, so it’s impossible to know whether the masks played a role in the boys’ deaths. But it raises the question, is it safe to exercise with a face mask on during Covid-19?”
Ms Bottoms ran on a treadmill at 10kph for three minutes in full fencing kit, both with and without a face mask.
Without the face mask on, her concentration of oxygen was 19.5%. With the face mask on, her oxygen levels dropped to 17% – the equivalent of exercising at 1,500 metres.
She said: “Any further decreases in oxygen concentration – by exercising longer or harder – would have a large effect on the physiological responses to exercise, causing altitude-sickness symptoms such as dizziness or headache.”
She added: “With gyms looking to reopen and sports clubs wanting to resume, before anyone recommends wearing a face mask, research urgently needs to be undertaken to ensure the safety of the sporting community, regardless of any underlying conditions.”