High levels of aerobic fitness are the best predictor of longevity, according to cardiologist Dr Paddy Barrett, who has attracted an international following for his expertise in prevention of heart disease.
Feeling how puffed you are after running up two flights of stairs might be a clue to how you are faring on that front. But a more insightful and scientific approach is to measure your VO₂ max. This is the maximum rate at which your body can transport and use oxygen to fuel muscles, expressed in millilitres of oxygen consumed per minute per kilo of body weight.
“The higher your VO₂ max, the longer you are likely to live and the less likely you are to develop the major chronic diseases of heart disease, cancer and dementia early in life,” says Dr Barrett, a specialist in heart disease prevention and cardiovascular risk management at Blackrock Health in Dublin and author of Heart: An Owner’s Guide (Dorling Kindersley, 2024).
No wonder then that there is growing interest in this key “metric” for the probability of enjoying a longer lifespan and, perhaps more crucially, an extended healthspan, ie well enough to enjoy an independent and active life. Of course, the proverbial bus, literal or metaphorical, can still come along to confound any such expectation, but it is an important indicator of odds.
More than half the Irish population have a smartwatch on their wrists and many will be familiar with at least the option of using it to get a VO₂ reading. But these are estimates conjured up by algorithms based on the device’s measurement of pace and heart rate, with no breath analysis involved. Some brands are regarded as better than others in their fine tuning of those algorithms for accuracy
Long before the development of consumer wearable trackers, American doctor Kenneth Cooper devised a test for the US military in the 1960s to measure aerobic fitness. This is still popular today as a self-test for VO₂ max. It involves measuring how far you can run in 12 minutes and putting that figure into an online Cooper test calculator. The result can be used to look at how your VO₂ max compares within the range for your gender and age group.
However, the only way to get an accurate VO₂ reading is to take a test wearing a mask connected to a machine that assesses the body’s oxygen consumption while gentle movement is ramped up to full exertion. A process that was once confined to elite sports circles and research labs is becoming increasingly available to anyone interested in learning more about their fitness. Some corporate workplaces now organise on-site testing as a perk for employees.
Seán Kinane came across VO₂ max testing when he was working in a gym in Perth, Australia, in 2009. Two years later, he set up Health Matters based in a gym in Tallaght, Dublin, working with athletes from a variety of sports. But he has seen demand grow “exponentially” in recent times.
“We’re doing nearly more tests in a week now than we did in a year,” he says of both VO₂ and resting metabolic rate testing, with work in corporate care having taken off in the last few years. He attributes this to people generally being more aware of health and fitness post Covid, and also to the influence of global guru Dr Peter Attia, “beating the drum from America about the longevity aspects of VO₂”.
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The link to longevity is very much the focus of siblings Elizabeth and Daniel O’Mahony, who this month opened AgeLess in South Dublin to offer testing for VO₂ max and/or resting metabolic rate. (The latter calculates the number of daily calories an individual needs to function while at rest and is used as a tool in weight management, be that to lose, gain or maintain.)
“We’re not saying that we’re going to increase people’s lifespans or make people live to 100,” says Daniel, sitting with his sister in a pristine office suite in Sandyford’s South Beacon Quarter. But they are confident that their “gold standard” equipment here can give people very useful data for longevity and working towards fitness goals, be that to run a first marathon or still be able to play a round of golf at 85.
Test results, he explains, can help predict what decade physical activities are likely to start to become difficult for an individual if they continue on their current health trajectory. An individual’s VO₂ max typically declines by up to 10 per cent for every decade after the age of 25 to 30 but exercise helps counter the extent and impact of that decrease.
AgeLess is a significant change of direction for the O’Mahonys who were both involved in the family property business for about 20 years. They were looking for an opportunity to strike out on their own and share their passion for health and wellbeing, sharpened by the experience of the Covid pandemic
Daniel, who is 39 and a former smoker, says that, like many millennials, he did not think about long-term health in his 20s. But then he became an avid runner and participates in ultra endurance events. He finished 72nd in the 2021 Marathon des Sables, a gruelling seven-day race covering 250km in the Moroccan desert, and now has his sights set on next year’s Ultra Trail Mont Blanc, a 117km run around the mountain involving an elevation gain of 10,000m.
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Elizabeth, who is 44 and a mother of two children, aged seven and four, has only taken up running recently. Motherhood, particularly having her second child during the Covid pandemic, made her more aware of her own health and the importance of physical activity for the whole family. “For me just being able to get out and have a run in the evening or at the weekend is great for the soul. I wouldn’t be doing ultra marathons or anything like that, but I’ve signed up now for the Women’s Mini Marathon on the 1st of June,” she says.
So what is involved in this test to find out how well your heart and lungs deliver oxygen to muscles? At AgeLess, there is the choice of doing it on a treadmill or exercise bike – or on your own bike fixed on a stand.
For those using the treadmill, the speed and incline is gradually increased as their respiratory exchange rate (RER) is measured through the use of mask and tubing connected to a monitor, for the VO₂ max calculation. At initial walking pace, the RER will read 0.8, indicating that the person is using fat as their primary fuel source.
“As they get to a higher level of output on their exercise,” says Daniel, “they switch over into carbohydrates as their main fuel source and the RER will have gone from 0.8 up to 1.0 and then when it hits 1.1 for anyone, that’s considered a maximum effort.” At that point all the necessary data has been captured and while more competitive clients may persevere for a bit longer, others will indicate they can do no more with a thumbs down or by hitting the stop button.
“The test itself normally lasts between 12 and 15 minutes and the last three minutes are probably the hardest for people because that’s when they’re actually getting to their threshold,” says Elizabeth. Non-runners can opt to do a walking test using steeper inclines on the treadmill.
The information readouts, which include tracking of heart rate, calories burned through the exercise test and speed of heart rate recovery, are then put in context for the client. The VO₂ max score is only part of somebody’s fitness story. But once they know their baseline, the next thing to be thinking about is how to increase that.
Dr Barrett’s advice is: “If you want to be above average later in life, you need to be above average now. Falling into the ‘average’ range for your age and sex is not good enough. You need to be above average at a minimum, but ideally in the top 25 per cent.”
AgeLess is partnering with personal trainers, nutritionists and physiotherapists to work with clients seeking detailed, professional advice on how to act on what their VO₂ max result is telling them. They may want to look at improving their lean muscle mass and their nutrition.
If clients choose to have their resting metabolic rate (RMR) measured as well, or come in just for that, the test involves simply sitting on a sofa connected to a monitor for 20 minutes. Both tests, as part of a “longevity bundle”, cost €150. Individually, the fee for VO₂ max analysis is €110 and €80 for RMR analysis.
“Having a good, lean muscle mass with a high VO₂ max is the ideal place to be,” says Daniel, who stresses that small, compound behavioural changes add up over time. “What we would ideally like to do is get our clients, over the years, up into that 75th percentile; to have everyone aiming for what is quite an achievable percentile to be in.”
Ciaran Burke of The Performance Lab (thepeerformancelab.ie) in Clonmel, Co Tipperary, has also seen a surge of interest in knowing and tracking this fitness marker. A strength and conditioning coach who became an exercise physiologist six years ago, Burke was mainly providing testing to athletic and triathlon clubs at the outset but now goes into mainstream gyms.
With rising participation in Hyrox and other forms of hybrid fitness training, people “are just trying to find the little percentages that the athletic world, or the endurance world, already knows about”, Burke suggests. “My guiding principle is to make sure they know how to inject what they’ve learned into their training.”
While the majority of his work is still sports performance related, Burke notes that there are also people in their 60s and 70s coming to him to get a VO₂ test “just to sort of get a handle on what’s going on”.
After a baseline test to inform somebody’s fitness training, noticeable change should be achievable within 12 to 15 weeks if they are following their programme correctly, he says. But he finds people are “shocking” at judging intensity of training. The rough guide for increasing VO₂ max is that just 20 per cent of training should be high intensity for that individual, while the rest is slow, steady effort.
A person’s VO₂ max is not the be all and end all, explains Kinane. An athlete with a lower level could outperform a fellow competitor with a higher VO₂ max because they train smarter. It is a number that “doesn’t guarantee performance, it guarantees potential,” is how he likes to put it. “It’s learning about how to use that through training zones and energy systems and fuelling. And that’s where the metabolic analysis then complements the VO₂ stuff.”
Elite athletes apart, dietitian Sarah Keogh of Eat Well is a bit dubious about the value for the average person of knowing the very precise number of daily calories their body needs just to function. In her work, RMR is occasionally used for somebody, say, being tube fed in an intensive care unit.
However, she acknowledges that for some people this number can be very motivating in calculating and sticking to an eating plan. Her main concern is where it might increase food anxiety and rigidity over daily consumption, to the detriment of good mental health and a social life.
