A man who ran 401 marathons in 401 days has started his next challenge - to keep moving on a treadmill for 24 hours.
Ben Smith started the challenge at 10am this morning (25 March) at PureGym in Portishead, but despite being an ultra-athlete, Ben said he was nervous.
He said: "I've got that pit of anxiety in my stomach because you never know if it is going to work.
"24 hours on a treadmill indoors is tough. At least for the 401 challenge, I was outside seeing nature. But I have amazing people next to me and I have 140 people coming to support me, so hopefully I can keep mentally strong."
It was PureGym Portishead manager Melissa Taylor who came up with the idea of the 24-hour treadmill challenge as a way of raising money for Ben's 401 Foundation - a national mental health charity.
She said: "Ben is mentally strong so he will be ok. He is worried about the early hours of the morning where he might get delirious but I reckon he will get through it. I'm going to be on the treadmill next to him through the night to help support him."
Ben hit the headlines when he completed his 401 challenge in 2016 - having run 401 marathons in 401 days.
He was bullied as a teenager and took part in the 401 challenge to raise awareness of how devastating bullying can be. He raised more than £330,000 pounds for charity.
The people who supported Ben for the 401 challenge were in Portishead today to show their support once more.
"I ran with Ben for the 401 challenge," said Teresa Whatty. "Every time I was always at the back but I was always included, he made sure of that."
Supporter Colin Spence first met Ben when he joined his running club. "Running can bring you out of your shell," he said. "Ben has been an inspiration for so many people of all ages."
Ben is hoping to raise £4001 for the 401 Foundation, so that it can continue to help support community mental health initiatives.
"I know what it is like to suffer from depression and not wanting to get out of bed in the morning," said Ben.
"Part of what our foundation does is help community projects which aim to improve mental wellbeing and now more than ever these projects need our support."
Anyone aged 16 or over is being invited to run with Ben, with slots available to be booked. Each 15 minute running session costs £4.01 and any further donation goes straight to the Foundation, minus an admin fee.
Ben will finish the challenge at 11am on Sunday, one hour later to reflect the clocks going forward overnight.