Matthew walked and ran an average of 62km a day on the challenge without any support, with only his mobile phone for navigation and contact with his family and friends.
Matthew says his goal was to do the trail in 15 days.
"I gave myself a 50-50 chance of pulling it off. From the start I gave it my all, knowing I'd be more likely to crash and burn going quickly than to do it in longer than the previous record of 18 days.
"I'd make early starts, up at 5am, and would walk until 8pm or so. Being up against the clock I only ever had short breaks in the day. People keep asking what kept me going, and a big part of it was knowing that I had an army of supporters back home who believed in me, but at a basic level it was all about sticking to my scheduled mileage, taking one day at a time."
He says it feels amazing to have completed the trail.
"It made me think how if this nerdy asthmatic can do this then no one has to have limits put on them. If you really want something, go for it.
"I decided to do this after my travel plans were scuppered due to Covid and started training during lockdown. This gave me a goal to work towards and to have pulled it off feels pretty awesome."
Matthew says the further north he went the more remote the shops and facilities became.
"Having to ration my digestives for lunch was hard, and I really wasn't taking in enough energy towards the end. I was so lucky not to ever have to buy water, I mostly topped up from streams.
"It was such a great way to see remote parts of Scotland. I had read about the trail and it seemed like a brilliant way for me to get a snapshot of many different iconic Scottish landscapes in one trip. But it normally takes 5-7 weeks and I couldn't take that much time off work – that's why I started to think about going for the record."
Matthew says the hardest part of his hike was getting up so early and getting going but says once he started "it was never as bad as I feared".
One of his highlights was when a woman he did not know stopped him while he was passing through Callander and wished him luck after reading about his record attempt on social media. And he says he will never forget rescuing the sheep whose all four legs had fallen through a cattle grid near Glen Almond.
He says when he finally reached Cape Wrath just after 1am on September 25 – exactly 13 days, 19 hours and 35 minutes since leaving the other end of Scotland – he enjoyed sleeping inside the small visitor centre there before hiking another five hours back to Kinlochbervie.
Along with setting a record Matthew aimed to raise £1 for every 1km he covered for WaterAid Scotland. He has already raised almost £4000 (NZ$7790.34) for the charity which provides safe water facilities in some of the poorest areas in the world and is the official charity of Scottish Water.
This was not the first physical challenge Matthew did this year. In summer he completed the Bob Graham Round in the Lake District when he climbed 42 peaks over a 106km route in less than 24 hours.
Matthew says he is now taking break to rest his body and catch up on sleep. He is already thinking about his next running adventure, but admits "it will be nothing as ambitious as this one, this was once in a lifetime".
To sponsor Matt's record breaking challenge go to www.justgiving.com/fundraising/matt-walks