Everyday Runner Mack Dewar’s Journey to Sub-3:15

Mack Dewar seems comfortable on both sides of the camera. By day, he's the co-founder of Floor Twelve, an Aotearoa New Zealand creative studio specialising in photography and video production. In his job, he’s created campaigns for a wide range of brands, including those in the running and outdoor spaces. In his leisure time, he turns the camera on himself, documenting his running experiences on his YouTube channel.

It's a journey that's seen him make incredible strides in a short amount of time. He ran his first marathon in 2021, under hot Hawkes Bay sun, for a time of 4:29. In April this year, Mack ran the Christchurch Marathon in a personal best of 3:14:36, an impressive 14-minute improvement on his time of 3:28 in the same race just one year prior.

Better still for the rest of us, he’s shared how he got there in a video series that covers topics such as the gear he uses, his top three tips on what he’s learnt to become a better runner, peak training weeks, and tapering.

Now, we know – and more importantly, Mack knows – that 3:14 isn’t the fastest time out there. (Compare this with our ongoing series on Lostboys leader Tim Rossi’s goal of breaking 2:30, which is testing the limits of what a dedicated amateur runner can achieve.) But that’s precisely why Mack’s videos are useful to a wide band of us.

“In the reality of it all, I'm a very average runner,” Mack says. “I feel like that's more relatable than what you might usually see on Instagram or TikTok or YouTube, where it's often these semi-elite runners.”

By sharing his own learnings, Mack hopes to inspire other everyday athletes to chase down their goals. “It's like, how can you make running more approachable for people,” he explains.

His videos also offer great lessons in content creation. Mack’s experiments on different platforms (he used to write on Substack, for example) and with different formats – short-form on Instagram and TikTok, long-form on YouTube – show the way as more people try their hand at making content. He’s always there in the comments, giving constructive advice on questions asked or just acknowledging positive feedback, and it’s intriguing to see that plenty of people are interested in how he makes his stuff as well as what he’s imparting as a runner.

Handily, in Episode 5 of his sub-3:15 series Mack explains how he got into running in the first place. In 2019, experiencing anxiety that manifested as chest pain, he visited his doctor, who told him there was nothing physically wrong with him. To prove this for himself, Mack went for a short run.

Which soon became longer and longer runs as he found something that made him feel great. He’d tapped into the runner’s high. And though, as he admits, he had no idea whatsoever about technique or heart-rate zones or anything else – and would come home “completely gassed” – he loved it and kept upping the miles (too much, too soon, leading to an injury) and soon completed his first half marathon, in Queenstown in 2020. The following year, he’d debut in the marathon with that 4:29 in Hawkes Bay. Before the race, he naively thought he’d easily get four-hours flat. He would later describe this in a Substack post:

“I was a complete rookie and that transferred over into my marathon training. I honestly don’t remember a lot of what happened in the lead up to [the] marathon training-wise but, based on my Strava, I just didn’t do enough running, plain and simple. I was just a bit lazy, had a goal of running under four hours and truly believed I could do it. My longest run in the lead up to it was a 25km and I was cooked by the end of it. The night before the race, we all decided to eat McDonalds and pizza as our pre-race meal. As you can imagine, terrible idea. I barely slept that night, excruciating headache, I almost was at the point where I didn’t run. That would of been the easy option.”

But he did run, and he did finish. He kept running. In June 2023, inspired by the vibrant crew culture he experienced while visiting New York City, Mack founded Floor Twelve Run Club (the agency already had merch printed so it was easiest to keep the name, he jokes) in his hometown.

“New York is the mecca for run crews. When I came home, there was nothing really in Christchurch that was run on a weekly basis,” he says. “Everything was based around 12-week periods in the lead up to certain races. I wanted to facilitate something for people to be able to come and run every single week regardless of what was going on, you know?”

Mack would get a chance to return to New York in 2023, when New Balance tapped him as one of five amateur runners from Australia and New Zealand who would get the chance to run the marathon. (Tempo worked with New Balance on this inspiring project and again for the 2024 London Marathon.) In November 2023, Mack clocked a time of 3:39 on the notoriously tough Big Apple course.

From there, he came up with his goal of going sub-3:15 in Christchurch the following April. So, how did he do it? In his YouTube series, Mack details some of the key changes he made to his training in the lead-up, including increasing his peak weekly mileage from 70 to 85 kilometres and adding strength-training sessions.

“I think that [the strength training] really helped with increasing mileage and staying away from any form of injury,” Mack says. He was also working with a coach, Andy Good, who he’d engaged for his New York preparation. This allowed Mack to string together consistent training blocks and build on the fitness he'd developed in the lead-up to NYC.

“Basically, after New York, we just continued working with each other and then sort of built into a 12-week block for Christchurch,” Mack says. “That in itself definitely helped, having a good base before heading into a proper block. You're not trying to play catch-up throughout, like trying to build mileage while also putting on long runs and speed workouts and whatever on top of that.

“So yeah, coach – big, big unlock.”

With a 3:14 PB now in the books, Mack has his sights set on even bigger goals in the years to come. Of course, he has a video for that. In it, he talks about picking himself up after getting the post-marathon blues. For now, he’s relaxed away from structured training and isn’t currently working with his coach. He’s only catching his breath before going again.

“Ideally, the path is I get into London next year,” he says. Though he also knows that it’s a record-busting ballot of 840,000 applicants; he estimates he has a one-in-18 chance. But assuming he pulls that off, the plan is to “run London, run sub-three and a Boston qualifier, and then run Boston in 2026”. Plan B: if not London, then a BQ somewhere else in 2025.

And as for how he plans to make those dreams a reality? “Uh, just running more,” he says with a grin. It might sound simple but, as Mack has shown, big dreams often have humble beginnings.

He’s also got plenty more content coming our way. Just over a week ago, he shared a video of two elites running the same 2024 Christchurch Marathon he set his PB in. One of those two runners is Mack’s coach, Andy Good. He came home first that day, in a time of 2:21:38, paced for the first 32km by his friend – the other runner in the video – Oska Baynes.

Oska was mic’d up on the course and that audio, combined with his and Andy’s post-race breakdown of their race footage, offers a rare insight into all the micro-decisions that make up a top-level race.

Mack is now working with Oska on a new content series as Baynes prepares for the Gold Coast Marathon in July. We’re looking forward to following that!