Fenn, 23, speaks from experience. The former cricketer has taken on the challenge of breaking world running records to get people talking about mental health, and it all started when he found himself having thoughts of ending his life at 18.
"I found myself in an apartment in London alone in the middle of winter. And I was struggling with thoughts of taking my own life. Because I had no purpose and no reason to keep going," he tells the Herald.
"Cricket was part of my identity at the time and when it wasn't going well, it literally felt like the end of the world. I'd put everything into it and then it was not worth it."
It was running that helped him find his feet again, inspired by a chat with a mate at the gym.
Finally, this month he announced on Instagram that he would begin running and wouldn't stop until 1 million people had commented on the post. It doubled as the world record for the longest single-stage run ever completed.
"The running actually doesn't matter. It's just a vehicle to carry the message that we're trying to encourage people to pay attention to," Fenn says.
Matt Fenn says running helped him get his own mental health back on track. Photo / Seb Charles @sebcharles
According to the rules laid out by Guinness, the run had to be at least 100km every 24 hours, and he couldn't stop for more than two hours at a time, preventing him from sleeping.
But it wasn't long before the pressure of breaking running records caught up with him, he says - this latest run ended in a trip to the hospital.
While he felt prepared beforehand, around 421km in he had to stop due to foot fractures. "It was a 10 out of 10 for pain for hours on end."
As he rested, his body started to shut down as a result and began to go into a seizure, leaving him hospitalised.
"That was quite scary because I was locked in my own body and didn't know what was happening."
Medical staff said the seizure was due to sleep deprivation, and emphasised that Fenn had taken every precaution to run safely.
Regardless of the outcome, he's still satisfied with the results of the run. At the time of writing, his original post was up to 32,000 comments.
"That's a hell of a lot. Long way from a million, but also so much better than we were a week ago."
Since the run, Fenn's been forced to slow down and think about his own mental health as a result, he says.
"I've done three big challenges in the last eight months and it's taken a big toll. I've been putting change in the mental health space above my own mental health and neglected that, and that's really tough.
"It's a little bit ironic," he laughs. "When you're pushing for change and encouraging people to do things. That's why I feel like it's actually really important for me to say that, actually I'm tired and I need to go and rest."
Matt Fenn has broken running records - but admits the pressure has forced him to slow down. Photo / Reagen Butler @reagenbutler
In September, the Ministry of Health launched a long-term plan aiming to transform New Zealand's approach to mental health.
The foundation's CEO Shaun Robinson told the Herald far more funding would be needed in the long run.
"For years we already had an ongoing crisis in mental health, neglected for decades by governments of all colours.
"This is bringing together the two biggest issues in New Zealand health, and we need to be in it for the long run."
A spokesperson for the Ministry of Health acknowledged there has been increasing pressure on the mental health and addiction sector for some time.
"This is not new, and we have seen an overall increase in the numbers of people accessing mental health and addiction services as awareness of mental wellbeing grows," they told the Herald.
"This demand on services can result in people having to wait for support."
While mental health has come a long way and is no longer the taboo topic it once was, that's still not enough according to Fenn.
"I think we talk about mental health, but we don't do a whole lot. Yes, you reposted this thing on your Instagram, but did you then go and have a conversation and check in with someone? And that's what I've started to try and do is leave people with an impression that keeps them thinking about it."
There's no clear solution when it comes to the mental health crisis, he says.
"It's a difficult question. It's a complex problem, and I don't know the answer."
"The biggest thing is not just talking about it, but actually having real discussions with people and doing things for them.
"I feel like we've seen that over the last five years. But there's a really long way to go."
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