Pulsing disco lights. Thumping dance music. Lithe bodies in motion, sleek in the latest designer styles. Whoops and hand claps. Serotonin levels spiking. Air heavy with pheromones. And, in the thick of the action, your intrepid longevity columnist, schvitzing like a senior citizen trapped in a sauna.

Not, alas, a scene from a glitzy bacchanalian nightspot in the early hours of a Saturday morning. Instead, on a blameless Thursday lunchtime in the genteel London suburb of Richmond upon Thames, you find me halfway through my first-ever high-intensity interval training (HIIT) class at Third Space. Can I feel the burn? I can’t feel anything except the burn.

The class is called WOD: Workout of the Day. It’s run by an energetic young woman named Georgia, who barks instructions through a headset, urging us on. There are eight of us: six women, two men. The other chap is a heavily muscled, faultlessly groomed stranger in his early 30s. I am paired with him for the “synchronised” portion of the WOD, meaning I must match my press-ups to his, rest while he squats, and vice-versa. Do I detect a pity-taking slowing in his rhythm when he realises that his training partner is not quite at his level? Reader, I do. In an unspoken compact, he is quite plainly going easy on me. By such tender mercies is one’s faith in humanity restored.

My walk back to Richmond station is slow and unsteady, rubber-legged. It’s accompanied by a realisation: perhaps the fitness “routine” of my previous life – irregular Pilates classes and a sluggish bi-weekly shuffle around the park – was not as gruelling as it might have been. If the aim of the exercise – and of HTSI’s The Longevity Project – is to increase my chances of a long and healthy life, I’m going to have to step it up a bit.

The Longevity Project author Alex Bilmes with his dog, Woody, in Hammersmith, London © Peter Flude

What’s the difference between running and jogging? I’ll tell you: one indicates the swift, fluid movements of a person in full command of their finely tuned physique. The other suggests, accurately in my case, a reluctant middle-aged man in Lycra – a Mamil – dragging his sorry behind around his local streets on a Sunday morning with the loping gait of a lame dog and the sunny facial expression of a person who has just dropped a dumbbell on his toe.

I like to say I’m going for a run. Most of us do. I wear running kit to do it. And running shoes. And I use a running club app to log my distances (not very far) and times (not very fast) and occasionally to supply motivation. “You’re a rock star!” says Coach Bennett, the Nike Run Club app cheerleader. Which is kind of him but also, I’m afraid, a bit of a hamstring stretch. I am no one’s idea of a rock star.

Jogging alone won’t help me live forever. As any smartarse lard arse will tell you, Jim Fixx, who is sometimes said to have invented jogging, died of a heart attack at the age of 52, in 1984, while out on his daily run in Vermont. The fact that 52 is my own age as I dust off this mildewed factoid does not lessen its impact, at least not on me. There is much science linking running – and other cardio such as cycling, and even jogging, and even walking – to a longer and more productive later life. But to be able to run – or jog or walk – confidently into one’s later years, it is, I am repeatedly assured, advisable to do a good deal more than occasionally lace up your flashy fluoro sneakers.

Unlike so much of the contradictory pseudoscience that infects the “wellness space”, it’s hard to find anyone who disputes the idea that regular physical exercise is a key component of a healthy lifestyle, and that it could – could – help you live a longer, or at least a better, life – if at least one measure of “better” is your ability to sit, stand, bend and roll over.

Exercise is the OG biohack. It helps to fight inflammation, believed to be a driver of ageing and disease. It stimulates the production of new mitochondria, increasing energy metabolism. It improves the body’s response to insulin, reducing the risk of type 2 diabetes. It’s also good for the brain, supporting cognitive function and potentially reducing the risk of dementia. An Australian study, published in The British Journal of Sports Medicine, found that 150 minutes of vigorous physical exercise per week “seems to promote healthy ageing”. The NHS guidance goes further, recommending an additional two strength-training sessions. One hundred and 50 minutes is two and a half hours. Surely I can manage that?

A class at Third Space © Rich Maciver

The Richmond HIIT class was not my first experience of Third Space. In August, at the gym chain’s Mayfair branch, I booked a consultation in the Performance Lab, where a young man named Harrison, with thighs the size of medicine balls, ran a battery of tests to assess my current fitness levels.

Something called an InBody scan assessed my weight (80kg, if you must know), skeletal muscle mass (34.2kg), body fat mass (19.7kg) and body fat percentage (24.4). A machine called a Shosabi – “an advanced AI driven movement analysis” – then gave me marks out of 10 for various movements that Harrison demonstrated and I tried to mimic. Ten out of 10 (yeah, baby!) for arm circles and ankle mobility. Eight out of 10 for overhead squats. But a pathetic three out of 10 for side squatting – the result, Harrison assured me, of the back operation I had a few years ago, which fixed my slipped discs but not the sciatica on my left side.

There was more. To assess balance and power, I had to stand on one leg and then the other, hop up and down, and jump as high as I could from a standing start. Harrison then fitted me with a Tom Hardy-style face mask and had me run to exhaustion on a treadmill to measure my VO2 Max – the amount of oxygen I can absorb at “maximum exercise intensity”. Then the poor fellow had to take a swab of my back sweat for analysis. (I do hope Harrison is being adequately compensated for these indignities.)

Five ways to fight ageing

Aim for 150 minutes of vigorous physical exercise per week (BMJ)

**Try “exercise snacking”. **Instead of extended gym sessions, balance on one leg while you’re brushing your teeth, throw in 10 squats between meetings or get off the bus two stops early

Falling is a leading cause of death in older people. Build muscle and protect your bones by lifting weights: 60 minutes of resistance training per week has been shown to reduce the risk of all-cause mortality by up to 27 per cent (American Journal of Preventative Medicine)

**“The biggest bang for your buck is walking to the gym.” **A regular 30-minute walk can significantly reduce the risk of heart disease, stroke, type 2 diabetes and certain cancers

Future-proof your body. The six movements you need to practise: squat, bend, push, pull, lunge and rotation

The results were modestly encouraging. My VO2 Max is “indicative of strong cardiovascular fitness in support of longevity”. My movement is “generally balanced”, although the side-squat score is “noticeably low” – unlike the side squat itself. Strength profiling demonstrated “good overall results with minimal asymmetries, suggesting balanced muscular development”. My hand-grip strength is “well above normative values for the subject’s age and sex, providing a strong prognostic indicator of musculoskeletal robustness and positive ageing trajectory”. This I put down to the fact that I only recently released my fingers from their long and desperate cling to the corporate ladder. So, it’s not the kind of body that would shame Adonis. But at least we know where I stand. Yes, and sit and roll over.

It is all very well to be in possession of the data. One must know how to interpret it. Harrison told me that for my age I was in decent shape. Then again, so was Jim Fixx, presumably. If I am to maximise my longevity, there is much work to do. I was given an exhaustive and exhausting programme of three full-body workouts to complete each week. Goblet squats, push-ups, lunges, planks, pull-downs, deadlifts, bench presses, leg presses, split squats, sit-ups and more. And I’ve been trying to find time for all of those, as well as keeping up with the jogging and the Pilates.

The Performance Lab was created by Third Space’s head of education and fitness innovation, Josh Silverman, who sets the principles for training at the gyms and monitors emerging trends in sports science. In terms of longevity, he says, “there are a couple of major things. Most important, overall cardiovascular health – and the best test for that is V02 Max. Second, overall strength, which is the biggest indicator of skeletal muscle mass. And muscle mass equals bone density.” The second most common cause of injury-related death in older people, Silverman says, is a fall. As you age, your muscle mass reduces, your bone density reduces, and so falling over can be fatal. Working out is equivalent to taking out an insurance policy against later calamity. Third Space’s philosophy, he says, is “training for life”. Not just for abs.

Rowing during an Energy class at Basis London © Paul Fuller

Silverman’s number-one piece of advice for beginners? “Walk for 30 minutes. The biggest bang for your buck is walking to the gym. Then you use the gym to bulletproof yourself against injury.” Nutrition advice? “Don’t eat too much.” Almost all other dietary advice is snake oil: “Ninety per cent of it is marketing.” “Longevity,” he says, “is about enjoying your life.”

One UK fitness industry report from 2024 counted just over 7,000 gyms and health clubs in the UK, with more than 10 million members – about 15 per cent of the population. Third Space has 15 gyms across London, from Wimbledon to Wood Wharf, each more sybaritic than the last. If only to compare and contrast, I decide to try a less luxury-focused operation. If Third Space were a person it might be Ivan Drago, Dolph Lundgren’s flat‑topped Russian titan from Rocky IV, using every development in modern technology to maximise performance in a climate-controlled body-sculpting studio. Basis London, by contrast, is more Rocky Balboa, Sly Stallone’s scrappy blue-collar hero.

Founded in 2022 by BJ Rule and Tom McAdam – both experienced PTs – Basis, Rule tells me, aims to provide “real high-performance training, accessible to everyone” in converted railway arches close to east London’s trendy Broadway Market. For £140 a month, Basis offers a general strength and conditioning class programme, just as you might find in the weights room of an athletics club or a rugby club. (Rule has a degree in exercise science but he also played rugby league in his native Australia.) The programme works in 12-week cycles but you can start – or stop and then rejoin – at any point. As at Third Space, members are also free to rock up any time and work out on their own or with a personal trainer.

I start with a Wednesday morning class. There are 18 people, an even split of men and women, most in their 30s and 40s, all local. After a strenuous warm-up led by Rule, we collect our bars and prepare for action: deadlifts, reverse flies, chin-ups, Z presses, ring dips, weighted pistols. Reassuringly – at least for this aching duffer – abilities vary. Everyone works at his or her own capacity but at the same level of effort, as dictated by the programme. It’s challenging, but also rewarding: in the following weeks add an extra weight to my pole, or a couple of reps to each exercise.

A class at Basis London © Paul Fuller

Rule talks about lifespan versus healthspan. No one can guarantee you a long life but following a strength and conditioning programme gives you a better chance at it. “Do you want to be as vigorous as you can for as long as you can?” he asks me. “If you do, that’s what strength training does. It’s why lifting heavy weights is really important: it builds bone density and muscle.” There are, Rule says, a limited number of movements that the human body performs: squat, bend, push, pull, lunge, rotation. He balances combinations of all these across each week, increasing intensity as he goes. The point of all this is not to sculpt a beautiful body – though that might be a side benefit – but to get fit and feel good.

Basis is a schlep for me. Third Space too. There’s a well-run, local authority-funded leisure centre just down the road from me, Everyone Active. My kids learnt to swim there, and I’ve used the gym sporadically over the years. But even that requires a certain amount of faffing about, getting changed, showering. An hour’s workout still seems to take two hours out of my day. Many of us struggle to devote an hour a day, or half an hour a day, or 15 minutes a day to exercise, so adding travel time to that is prohibitive. It also provides an excuse not to bother. Plus, gym membership is not cheap. Lavina Mehta, author of The Feel Good Fix (Penguin Life), has an answer for the harried middle-aged striver: “exercise snacking”.

What do you do while you’re brushing your teeth in the morning? Hum a happy tune? Stare disconsolately at the crack in the porcelain of the basin? Or do you, as I have been trying to remember to do, balance on one leg for a minimum of 10 seconds, then switch to the other leg, before executing 10 bodyweight squats, 10 hops on each leg, then 10 press-ups? All this while still in my jimjams. Exercise snacking is short bursts of exercise – just a few minutes or even seconds each time, spread out across the day, most performed while you’re doing something else. Twenty seconds of star jumps while waiting for the kettle to boil; heel raises while watching TV. It’s taking the stairs instead of the lift. Ensuring you move after each meal. According to Mehta, snacking is not only more efficient than doing one longer workout and then sitting at a desk for the next 10 hours, “it’s also better for boosting energy and mood”. Her book has a HIIT snack section, stretching snacks, strength and mobility training tips. The exercises are familiar – squats, press-ups, lunges, glute bridges, isometric holds – but the routine is innovative. Oh, gosh. That reminds me: 10.30am. Excuse me for 30 seconds while I plank. “Good for blood pressure,” says Mehta. All this is excellent advice, but I confess that, for all its apparent convenience, I find exercise snacking harder to maintain than the gym sessions. Left to my own devices, I immediately succumb to deadly sins: sloth, gluttony, doomscrolling…

This morning, after my eggs, I went to Third Space again for a barre class called The Method, which sounds uncannily like one of those body horror movies I’m too squeamish to sit through: The Witch, The Substance, The Method. I wasn’t able to sit through The Method, either. I was up and down like a barbell, thick rubber bands around my knees and ankles, using my “well above normative values” hand-grip to steady myself at the barre – rather than the bar, to which it is more accustomed to clinging. “Really good external rotation,” said the instructor, Jocelene. Not a compliment I ever imagined I would receive, but I’ll take it.

I won’t say I felt good, exactly, as I shuffled home and sat down to finish this piece. But I did feel something. Now, what exactly was it? Oh yes. Alive. I felt alive. And that, after all, is the point.

Third Space membership from £245 per month (thirdspace.london). Basis London introductory membership from £140 per month (basis.london)