This year’s Virgin Money London Marathon has been renamed the ‘mental health marathon’ as people from around the world come together to take on the challenge of the 37th edition of the race on Sunday.

Championing the ‘mental health marathon’ message are 10 runners who are living with, or have been affected by, mental health issues. They have come together as part of the Heads Together campaign to target two goals: train for the 26.2-mile challenge and tackle the stigma around mental health.

The group’s progress since they started training five months ago has been documented in a two-part BBC series Mind over Marathon, which examines the links between mental health and physical health and discusses how taking up sport or exercise can benefit our psychological wellbeing.

The first episode was shown earlier this week and is available on the iPlayer and the second will air on Thursday 27 April.

Chevy Rough, who has been coaching the runners since they started their marathon challenge, believes training for the race will benefit not only their bodies but also their minds.

“The goal of the documentary was to connect the dots between the mind and the body, which is very much what I do as a coach,” said Chevy, who escaped the Alpha-male environment of the City to become a personal trainer when he hit 30.

“We wanted to explore the relationship between movement – jogging, walking, running, anything really – and the mind and mental health.

“From day one I wanted to instil in the runners that running a marathon isn’t about getting to the Finish Line, it’s about understand yourself and building relationships for life.”

The runners may not have crossed that London Marathon Finish Line yet, but Chevy has succeeded in helping them build life-long friendships.

“I speak to the other Mind over Marathon runners more than I speak to my mates at the moment; we’re all really there for each other,” said Jake Tyler, who quit his ‘dream’ job due to depression.

“For want of a better word, we’re 10 damaged people, and we’ve all lived with a certain amount of guilt and shame and secrecy about what we go through for a lot of our lives, so to be part of a group where that’s the first thing you get to know about each other has been incredibly powerful.

“The group is a safe place for all of us. On the days that are hard, I can always see that things will get better at some point because I have this group around me – and Chevy has been relentless with his positive influence on us.”

The marathon training hasn’t been easy for any of the group, who have faced many challenges, both mental and physical, as they’ve prepared for Sunday’s race.

For Poppy Farrugia, the hardest part of training has been getting out of the front door.

“I suffer from anxiety and post-traumatic stress disorder, so I’ve found going out to run really hard,” she said. “I know I might have an anxiety attack or a panic attack while I’m running, so I try to run with someone else to prevent that.

“If I go on my own, I’m putting myself at risk because I don’t know how I will feel while I’m out there, even if I know I’ll feel amazing afterwards.”

Poppy supplemented her outdoor running with training in the gym, where she felt more comfortable. The challenge for Chevy was to help the runners find a way to train where they felt “safe”.

“Poppy has been really consistent with her gym work so there’s a real message there that you don’t need to run marathons,” he said.

“Going to the gym is something that Poppy really enjoyed. It gave her a safe place so the message from the documentary is you don’t have to train for a marathon, you just need movement – so that could be walking to the end of the road or walking around the block, or going to the gym,” said Chevy.

The challenge for Jake has been staying motivated but he’s optimistic that the support of the other Heads Together runners on Race Day will carry him to the Finish Line.

“It has been really tough for me to stay motivated – not because I didn’t feel running was helping me but because when you’re living with depression, there are times when you just can’t get yourself out the door.

“The hardest part of training has been trying to change my perspective on certain things. I’ve been trying to alter what I feel my ‘best’ is.

“If I’m having a great day, which I have had thanks to the running and the experience of meeting people like Poppy and Chevy, I feel like I can do anything, and I set the bar very high for myself.

“If I’m having a bad day or a bad week then my best might be simply getting out of bed and not pushing myself so hard that I’m not beating myself up about not going for a run that day.”

Chevy believes these insights will help the group to overcome their own personal challenges as the Start Line approaches.

“Marathon training gives you a blueprint to understand yourself,” he said. “When you’re training, not every day goes great; and in life not every day is great. It’s ok if you don’t go for a run today, just as it’s ok if you’re finding today quite hard. You build up a better understanding that life is not black and white.

“It’s about connection and community; getting people moving but also getting them connected to other people. That social connection can really help; they’ll connect and support each other through getting to the Finish Line but also beyond that they’ll have a community that can come together.

“This group for 10 people has really been transformed into a ‘crew’ by training for the marathon.”

Poppy and Jake are looking forward to using the tools they’ve been given by Chevy to carry on exercising well beyond the Finish Line on Sunday so that they can continue to reap the mental and physical benefits of exercise.

“We all share a common goal of wanting to move past a barrier and move forward,” said Poppy.

Find out how they get on at the ‘mental health marathon’ by watching the BBC’s coverage of the London Marathon on Sunday.

The second part of Mind over Marathon will be broadcast on Thursday 27 April at 21:00 on BBC One.