On his 30th birthday Dean Karnazes and his friends started celebrating with beers and moved on to tequila shots. Nothing too unusual there. Perhaps more unusual was that the night ended with him steaming drunk, running through the streets in his underpants. Uniquely, however, that birthday run lasted for 48 kilometres and seven-and-a-half hours. It was August 23, 1992, and the night Karnazes became a professional runner.
t wasn’t quite a cold start – the American had quite a bit of practice – but it had been a while. In school, he had been a track and cross-country prodigy until giving up abruptly in his mid-teens, due to a personality clash with his new coach.
In his 20s, having studied food science and business in university, he became a successful businessman and enjoyed all the usual corporate trappings: company car, cocktail parties, expensive nightclubs. But on that birthday weekend, something changed. Despite his success and relative wealth, he was feeling deflated and empty.
“My fear is that I’ll wake up 30 years from now and be in the same place, only wrinkled and bald… and really fat. And bitter,” he wrote of his feelings that day in his first book, Ultramarathon Man.
Thirty years on, Karnazes is none of those things. He has become something of a folk hero for marathon runners and has earned himself the moniker “fittest man in the world”.
He’s won the punishing 135-mile (217km) Badwater Ultramarathon through Death Valley twice. The race, which takes place in California in July, regularly sees temperatures of over 50C on a route that climbs 13,000ft. During one run, the heat was so intense it caused the soft tissue of his tongue and throat to slough off.
He once ran day and night for three days, over a 350-mile (563km) route. On the third night, he recalled: “I woke up running down the middle of the road and I realised that I was sleep running.” He has run to the South Pole, along the Silk Road, and from New York home to San Francisco.
Along the way, he married his high-school sweetheart, Julie, and had two children, Nicholas and Alexandria.
Now, at 59 and still running ultramarathons, he has published a roadmap for how to stay fit into your 50s and 60s, A Runner’s High. He also reflects in the book on the changes to his own body after two-and-a-half decades of running ultramarathons.
“I’m stubborn. I’m holding on to my younger self – if you saw the amount of effort I put into my training, I work twice as hard to be half as fast. But I’m not willing to say I’m going to hang it up or try something easier,” he tells me.
Now, at the start-line of a race, he sometimes wonders if he will be able to finish. “It’s a question I grapple with. ‘Am I going to be capable of getting there?’ Maybe I shouldn’t take on these challenges anymore. That’s still very much part of my mindset.”
The book opens with his spontaneous decision to run the Californian 100km Bishop High Sierra Ultra Marathon, despite not having trained. It is intended as a primer for the Western States 100-Mile [160km] Endurance Run, whose lottery for entry has “slimmer odds of getting in than being accepted to Harvard”. But with just three weeks to go, as he rises up the waiting list, he decides to “hack” his training. His last encounter at the Western States in 2009 ended “dreadfully” in a DNF (Did Not Finish).
“The thought of returning terrified me,” he writes. “The 2009 race had thoroughly kicked my ass; the DNF haunted me to this day. Yet I wanted – needed – redemption.”
But by mile 32 of Bishop High Sierra, it is clear this will be no simple primer. He berates himself for being “woefully undertrained”.
He begins to be lapped by younger runners. “My existential nightmare was affirmed. I didn’t so much fear losing to a younger kid; what I feared was losing my relevance. In a sport that had become my life, I didn’t want to fade away.
“As I continued running down the trail, I thought about myself as an ex-runner. I couldn’t form a vision of that man,” he writes.
“I’d come of age, and the battle was how to endure and persevere, how to extend a career doing what I loved while the clock ticked against me.”
A Runner’s High then is his manifesto for practical, positive ageing. He decides to “optimise” his body to compensate for any age-related slowdown.
That goal might sound fanciful but his approach is supported by science. Successive studies have shown that whilst exercise can’t reverse ageing, it may activate the processes necessary for DNA repair and can help stave off the ageing process.
Research conducted by the University of Birmingham and London’s King’s College studied 125 cyclists aged between 55 and 79 who had exercised most of their adult lives and compared them to non-active people. Over time, the cyclists did not lose muscle mass or strength. Their body fat or cholesterol did not increase with age and the men’s testosterone remained high.
Heart health can be of particular concern to men as they get into middle age. This is because, after 50, the arteries can begin to stiffen. But running can be especially beneficial. A 2020 study published in the Journal of the American College of Cardiology found that training for your first marathon can make your arteries four years younger and also positively impact blood pressure. It also reduced risk of stroke by as much as 10pc.
And so Karnazes prepared to return to the frontline. That meant setting up his body for endurance and longevity. The upgrades amounted to changes in four areas that apply to all of us as we age: diet, strength, sleep and relationships.
However, unlike most of us, Karnazes was already super fit and healthy. He has, for example, eaten Paleo for 20 years. He stopped eating pasta the night before races, as was the convention, because he felt bloated and sluggish at the starting line. He’s used a homemade standing desk for 15 years because he felt tired after a day sitting down answering emails.
So as to getting healthier in his 50s, there wasn’t a lot of low-hanging fruit. It was, to coin a term from a previous book of his, already pretty Spartan territory.
“I like to say if I can’t pick it from a tree or dig it from the Earth or catch it with my hands, I won’t eat it. Nothing refined or processed, it’s all-natural. I eat a lot of seafood, sustainably harvested wild seafood. Salmon and sardines are my main source of protein. I’m 100pc Greek, so I eat a lot of olive oil. And obviously a lot of greenery. It’s very much a Mediterranean-type diet. I don’t eat any wheat, bread, or pasta. No grains, basically,” he says.
Surely two decades of Paleo must be tough or at least boring? Nope.
“I don’t know if I’m extremely disciplined or if I’m playing mental tricks on myself. I have friends who walk past a bakery and they go crazy if they get the smell of a doughnut. I have no interest in eating anything like that.”
He’s virtually teetotal, drinking “maybe one to two glasses of wine a month”.
So, alongside a protein-rich and grain-free diet, he changed how he exercised, moving from gym-focused sessions to incorporating more training into his working day, somewhat redefining the office gym in the process.
“I used to go to the gym for an hour or two, and I started thinking, ‘Why can’t you work out continually throughout the day and make that part of your lifestyle?’
“So I bought a sit-up mat, I got a pull-up bar, and I put those in my home office. During the day, I started doing push-ups and pull-ups and sit-ups and burpees pretty much throughout the day. I have a 12- to 14-minute HIIT [High Intensity Interval Training] routine that gets my heart rate really revved up, and I do about five or six of those throughout the day.”
Performance to Karnazes is a holistic experience. It is not merely about muscle function and macro-nutrients, but about any element of his lifestyle that could impede his ability.
“I was one of those people that either didn’t have to sleep or just never slept,” he says. “Maybe I was somewhat of an insomniac. For 10, 15, 20 years, I slept for five hours a night. Now I try to sleep seven or eight. I found that when I slept more, I felt better.
“But I have to be disciplined because when my head hits the pillow, I’m not tired. I force my mind to slow down. I try to envision this silent cocoon around me, where there’s nothing to do except sleep. I try to quiet my mind. That’s how I’ve learned to sleep better. It’s a learning process, but I’ve really worked at it.”
His emotional life went under the microscope too. “I realised that as an athlete if you have harmonious interpersonal relationships with your friends and families and your colleagues, your performance in life is better. And, just the opposite, if you have a lot of discord in your life, it negatively impacts your performance.”
Lockdown gave him pause. He was travelling less and seeing his family more. He writes about going for a run without measuring the distance or timing himself.
“Running is not about racing or winning, it is about the human challenge and exploration of self,’’ he writes, having taken off his watch. “The experience is about you and the trail.”
Lockdown, he says, has whetted his appetite to get back out in public. “I’m very much an introvert. Often, I would go to races or signings, and I would feel very overwhelmed. I used running as therapy. That was my reward. I just had to get through the day, and then I could run for five hours by myself.
“During lockdown, I really missed those experiences with other people, and I never thought I would.”
He may be knocking 60, but this is not a man who is taking things easy.
“I don’t feel arthritic. I don’t feel like I’ve got back pain or bunions. Sometimes I feel like I’m in my 30s.”
But he does admit: “No one can last forever, and no one can be on top forever. But even in my decline, I’m still trying. And what matters most is staying true to the man you are, and still showing up.”
‘A Runner’s High: Older, Wiser, Slower, Stronger’, published by Atlantic Books, is out now
Future fitness: How to exercise into your 50s, 60s and beyond
Peak muscle-building age is from 30 to 35, but there are ways to prime your body for health long after. “There are four components to health-related fitness: agility, strength, cardio-respiratory endurance and ideal body composition,” explains Niall Moyna, professor of clinical exercise physiology at DCU’s School of Health and Human Performance. “Ageing is going to occur, but your lifestyle, including exercise, can have a dramatic impact on the rate at which your different organ systems are going to age.” Here’s how to get fit for the future.
Be a (jumping) jack
As we age, we lose muscle mass and bone density, so include weight-bearing exercise with cardio workouts. “Mix up cardiovascular exercise. Combine elements of walking, jogging, cycling and swimming,” says Prof Moyna. “It has to be weight-bearing to ameliorate that loss in bone health. Swimming and cycling won’t have the same impact as jogging or jumping or running. “We know that some swimmers’ bones tend to age a little bit more quickly, compared to other athletes, because of the lack of weight-bearing activity.”
Take up gardening
Resistance training doesn’t have to mean bench pressing hundreds of kilos, says Prof Moyna. “Bending down, standing up while you’re gardening or holding the spade – there’s no difference to that and holding a weight in your hand. It’s doing the same thing; it’s resistance against your muscles.” Nor do core exercises have to be crunches and sit-ups. “Go and see your physio. It just takes one session and they’ll give you appropriate exercises based on your current health and musculoskeletal balance.” Even better, he says core exercises can deliver “dramatic changes in as little as three weeks”.
Eat protein
It’s more challenging to build muscle as we age. “You’re not going to be able to build as much muscle as you did when you were 20, but you can maintain it.” Prof Moyna recommends consuming around 20g of protein half an hour before resistance exercise. This can be found in lean white meat and eggs, but also protein supplements.
Find a gym buddy
“This increases the likelihood you’ll continue to do the exercise. And social interaction as we age is very important.”
Best foot forward
Ireland has one of the highest race participation rates in the world, according to a 2019 report. At 0.5pc of the population, it’s more than double that of the UK and the US. Check out the 45km Wicklow-Dublin EcoTrail and the Karnazes-worthy 200km Kerry Way Ultra.