Running 30 marathons in 35 days is enough of a challenge to last most people a lifetime.

However, a sports lecturer from Clapham has decided to try and top his fundraising efforts by running 300 miles in just three days.

Jason Arday plans to spend up to 18 hours a day on the treadmill to complete the challenge, which will raise money for homelessness charity Shelter.

He will attempt the challenge at Fitness First in Clapham Junction on August 10 and 12 - and on August 11 will be at Latchmere Leisure Centre in Battersea. He aims to be on the treadmill from 6am to 10pm everyday.

The 26-year-old, who teaches at Richmond College, has raised more than £100,000 for charity since he started fundraising, aged 17, including raising £8,000 from his epic challenge of running 30 marathons in 35 days in July and August last year.

He hopes to raise £250,000 by the age of 50, but revealed this will be his last running challenge.

He said: I’m in no doubt that the 300 is going to be an incredibly difficult challenge. The good news is that I’m in great shape and have been training solidly for the last seven months.

I’m running around 15 miles a day at the moment - seven miles in the morning and eight miles at night. Quite often I start at 4am for the morning run.

"As this is the last running challenge I’m concentrating on just raising the £2,000 target for Shelter and Shooting Stars Chase and completing the 300."

To sponsor Mr Arday visit justgiving.com/the300.