Six years ago Justin Lang was in a very dark place.

"I wasn't planning on being around for the whole year," he told 7.30.

"I didn't have anything to live for."

One day it became all too much.

"It was a hot day, got home and pretty well snapped at that moment over the end of a relationship, literally just collapsed in the shower," he said.

"It wasn't heat stroke.

"At that moment I just broke."

Cycling 'kept me here'

Adelaide Fat Boys cycling group (Justin Lang standing at the back) enjoy a break on one of their rides. ( Supplied: MAMIL )

Justin Lang's breakdown came at the end of a bike ride. But cycling was also his saviour.

He said the only thing that kept him going was looking forward to future rides he was going to do.

"The one thing that kept me here was, oh, there's an event at the end of January that I'm looking forward to," he said. "There's another event at the end of March that we'll be cycling for seven days interstate."

How cycling changed Justin Lang's life is part of a new Australian documentary called MAMIL to be released in cinemas this week.

MAMIL is an acronym for 'middle-aged man in lycra'.

So big has the MAMIL movement become, that in 2014 the word was added to the Oxford English dictionary.

Justin is one man who has embraced lycra, and enjoyed both the physical and mental health benefits of cycling.

"The exercise and the endorphins can just be a really great way to start the day," he said.

And he believes the ritual of a post-ride coffee was key to improving his mental health.

"Everyone over the last few years has had a rough time at one time or another," he said.

"So it's a bit of a chance to check in, just bounce things off each other and just catch up and have a chat."

Comradeship, excitement the drawcards

Sports sociologist, Murray Drummond, says cycling in a group can be good for mental health.

Sports sociologist Murray Drummond from Adelaide's Flinders University said MAMILs were typically white-collar professionals.

Mr Drummond said it was clear cycling could help with depression and the mid-life crisis.

"The mental health that these men attain through being involved in cycling with other groups of men, I don't think can be underestimated," he told 7.30.

"They're with like-minded men and they're getting out of bed and they're engaging with a group of men that they're friends with."

"Going around a corner at 60 kilometres an hour is quite exhilarating, particularly when you're with other groups of men doing the same sorts of things," he said.

"For a lot of us, we don't get the same opportunity like we did in years gone by."

Justin Lang is now in a much better place.

He urges men to give cycling a go and to not to bottle up their feelings.

"If someone was going through a hard time, I'd suggest they firstly talk to someone if they're comfortable," he said.

"But try to have something to look forward to, realising that things will get better."