The Rugby Football Union, Premier League and Sport England are among more than 200 organisations backing a scheme to provide 21,000 coaches with mental health training by 2021.

Launched to coincide with this year's Mental Health Awareness Week, the #21by21 campaign eventually hopes to make basic first aid training for the UK's 3million active coaches as much about the mind as the body.

Five-time British long jump champion Jade Johnson is championing the scheme and told Press Association Sport: "Millions of young people take part in some kind of sport every week – that's a lot of coaches!

"Many of those youngsters don't want to talk to their parents or teachers about some subjects because they want to be independent and they haven't chosen that teacher to be a mentor – they're in transition, their bodies are going crazy and there is a lot of outside pressure.

"But a coach is just there to build you up and, as most of them are volunteers, you know it's not about money. They are doing it because they want you to succeed and they've got your back."

The 38-year-old, who won Commonweath and European silver medals in 2002 and finished sixth at the 2004 and 2008 Olympics, was coached by UK Athletics' former national long jump coach John Herbert, a Commonwealth triple jump champion.

"John was a great mentor to me," she said.

"I was feisty back then but no matter what was happening he would be calm – he set such a good example, he never got stressed or angry.

"(Youth sport charity) StreetGames asked me to give a motivational speech recently and I asked them if I could do it with my coach because I would not be standing there if it wasn't for him – he's family and that bond is still there."

And Johnson's experience is far from unique, as recent research carried out by Brunel University and StreetGames has demonstrated.

Their 'Sport For Better Mental Health' study found that two in five young people aged 14 to 24 would turn to their coach for emotional support, while one in five would confide in a coach about something that was worrying them.

Grassroots funding agency Sport England is one of the #21by21 campaign's key backers and its head of coaching Stuart Armstrong believes the fact so many young people would confide in a coach is "reassuring" but wants to empower those coaches to give even better advice.

"Coaches are telling us they want to feel more equipped to have conversations about mental health and want to know how to direct people to specialist support," Armstrong told Press Association Sport.

"The training, online and one-to-one, will help coaches understand how mental health can vary from day to day, the impact of stigma and how to address it, and to recognise signs of poor mental health in others."

UK Coaching works across sport to recruit, train and retain Britain's largely volunteer coaches.

Chief executive Mark Gannon said: "Coaching has always been wider than just the technical aspects – it's an art and a good coach will notice things others don't.

"The governing bodies are the best people to train their coaches in the specifics but we are here to help coaches get better equipped for everything that isn't tactical or technical – that could be mental health or managing finances.

"Three million people do some coaching every year so 21,000 with mental health training is only a start – I would like to get that up to 10 per cent."

Asked if he was worried that some potential volunteers might be put off by having to do another course or take responsibility for another's mental health, Gannon said: "Whenever new regulations come in, you do have to be mindful of that but there are two points to make.

"One, even volunteer coaches have a duty of care. And two, if you sell this right it could be a great learning opportunity. It could provide tools that might help them, their families or a friend."

Johnson agrees and believes most coaches will be "delighted" to add something so fundamental to their skill set.

"I always thought about 90 per cent of what my coach did for me was to do with stuff that was off the track," she said.

"He was a mentor and a counsellor as much as he was a technical expert or guy with a stopwatch."

– Now in its 19th year, Mental Health Awareness Week is organised by the Mental Health Foundation and runs from May 13-19.