Joggers should wear a mask when running past people, experts have said.

Trish Greenhalgh, professor in primary care health sciences at the University of Oxford, told Good Morning Britain: “There is no doubt the virus is in the air, there is no doubt that you can catch it if you inhale, and that someone else has exhaled.

“The exercising jogger – the puffing and panting jogger – you can feel their breath come and you can sometimes actually feel yourself inhale it, so there’s no doubt that there is a danger there.

“Forty per cent of Covid cases happen by catching it from people who have no symptoms – so you’re jogging along you think you’re fine, and then the next day you develop symptoms of Covid, but you’ve actually breathed that Covid onto someone perhaps you know, an old lady walking a dog or something like that.”

Devi Sridhar, professor of public health at the University of Edinburgh, added that people should wear masks in busy areas but when not surrounded by people they could “take off your mask and run freely”.