A grandfather who struggled to walk down the stairs after contracting Covid-19 is preparing to run his 37th consecutive London Marathon.

Harmander Singh, 62, of Wellesley Road, Ilford, tested positive for coronavirus in January, which led to him losing 12lbs in a week.

The retired local authority worker has run 163 marathons over the years but said he felt “doddery” after overcoming the virus and it took him four months to get back to running.

Describing his illness, he said: “In all my life that I’ve been working I’ve never had a day off sick, so it was a new experience for me. I couldn’t breathe.”

He did not go to hospital, instead isolating in an upstairs guestroom in the family home.

“After my isolation period finished, I found it a struggle to even come down the stairs,” he said.

“I took it one step at a time and was a bit doddery.

“There wasn’t any moment when I said I’m going to give up but I was becoming more realistic about what my chances were of ever running a marathon again. But I was determined.”

He said that the London Marathon was his favourite race and that running it would be the “biggest stepping stone to being normal again”.

Harmander, whose personal best time for a marathon is three hours 11 minutes at a race in Manchester, said he has no target time for the London event on October 3.

“I’m going to, for the first time in so long, genuinely going to just enjoy it,” he said.

Harmander is club president of the Sikhs In The City running group, which he described as the “only Asian-led athletics club in the UK”.

He is coach to 110-year-old Fauja Singh, who he said is the world’s oldest marathon runner – running his first marathon aged 89 and his last aged 101.

He has also completed the Great North Run every year for the last 37 years and said he wants to continue with both races until he is 74, meaning he will have run 50 of each.

Harmander is fundraising for Sporting Equals, a charity that campaigns for equality in all sports.