Intense exercise could HARM your heart, reveal experts… but tell what you must do instead

Working out in the gym for ten hours every week, hiking long-distances wearing a weighted rucksack, cycling intensively for long distances … would you be willing to exercise that hard in the hope of living a long, healthy life?

A new trend among celebrities for extreme exercise is being driven by the promise that spending hours in a hard sweat every day will put years on your life and ward off serious disease.

Yet medical experts are warning that the craze for extreme workouts is driving an increase in physical damage that could be dangerously harmful.

What’s more, new research suggests it’s actually light exercise, as simple as brisk walking, that may be our best bet for robust health in later years.

Most prominent of the longevity chasers is Dr Peter Attia, a Canadian-American physician and bestselling author of Outlive: The Science & Art of Longevity. His Drive podcast has been downloaded 100 million times.

Dr Attia is said to charge clients hundreds of thousands of dollars to undertake his tailored regimens of hard exercise, diagnostic tests and vitamin supplements at his clinic in Austin, Texas, with the promise that they will live significantly longer and enjoy better strength and health.

Celebrities such as actors Chris Hemsworth, Hugh Jackman and Gwyneth Paltrow reportedly follow his regimens. In his book, Dr Attia declares that exercise reigns supreme as ‘the most potent ‘drug’ in our arsenal’ when it comes to living longer and free of chronic illnesses such as heart disease and dementia.

That’s hardly a new message. Except that his kind of exercise is not for the faint-hearted. Muscle strength – from vigorous, hard exercise – is key. His regimen involves working out for an hour each weekday and for up to two hours on Saturday and Sunday.

Dr Attia, who is 51, practises what he preaches. He spends around ten hours in the gym every week, and is an endurance swimmer and cyclist.

He is also an avid ‘rucker’ – an emerging sport that involves taking long hikes in rough terrain carrying a backpack that contains 50lb in weights.

Dr Attia’s high-profile and extreme anti-ageing exercise efforts echo the efforts of Bryan Johnson, a Silicon Valley entrepreneur worth a reported £300 million, who proclaims himself as a ‘rejuvenation athlete’.

Johnson gets global headlines for committing himself to a rigorous anti-ageing programme of exercise, diet and supplements that he calls Project Blueprint.

It involves six days a week of 60 to 90-minute workouts, including lifting weights as heavy as 240lb and doing 60 press-ups at a time, as well as performing long, intensive sessions on cycling and rowing machines in his gym.

Johnson, 47, says his aim is to reverse his biological age to 18. While this has provoked widespread scientific scepticism, Johnson boasts that he now has the lung capacity and fitness of the fittest teen.

Similar boasts of the benefits of hardcore exercise are made by another American wellness advocate, Greg Lindberg, a 54-year-old business tycoon.

In his book, Lifelong, he claims that high-intensity workouts ‘activate cellular pathways associated with youthfulness and vitality’, partly by stimulating our bodies’ production of brain-derived neurotrophic factor (BDNF) and telomerase. BDNF is a protein that encourages the growth of new brain cells and their interconnections, and is involved in learning and memory.

In 2020, a study by the Karolinska Institute in Sweden found that levels of BDNF fall as we reach our mid-60s, but that exercise such as moderately fast cycling can prevent this, reported the journal Nature.

Telomerase, meanwhile, helps maintain our telomeres – the ‘caps’ on the end of our chromosomes that act like an aglet on a shoelace, and protect our DNA against damage.

Studies suggest that exercise can protect telomere length. The theory is that longer telomeres allow a cell to divide more times and therefore live longer. However, this is not clear cut.

A study last year by the Johns Hopkins University in the US suggested instead that long telomeres allow cells with age-related mutations to live longer, increasing the likelihood of tumours and some chronic health problems.

(Meanwhile, Lindberg’s wellness career received a setback last month when he pleaded guilty in a US court to a $2 billion fraud.) Yet the belief that extreme exercise really can boost longevity is highly controversial. While supporters quote evidence – such as a recent report in the British Journal of Sports Medicine that showed elite athletes who can run a mile in under four minutes tend to live nearly five years longer than the general population – other experts are sceptical of the entire concept.

David Stensel, a professor of exercise metabolism at Loughborough University, told Good Health: ‘There is not sufficient evidence to support claims that vigorous exercise will significantly extend longevity.’

Studies on people training intensively will show improvements in markers of health, such as BDNF, says Professor Stensel, but this is not the same as showing such things can extend longevity or prevent dementia.

‘Studies of more than 100,000 Britons’ exercise rates and health, taken from UK Biobank [a huge database being collected of genetic, lifestyle and health information] show that people who are reasonably more active than average tend to live a bit longer than people who are less active,’ says Professor Stensel.

‘However, that may just be down to the fact they’re healthier in the first place. Overall, the current evidence generally shows that mild physical exercise, rather than excessive exercise, plays a part in living longer and healthier.’

Other research suggests extreme endurance exercise may even cause significant harm. In a two-year study published in May, researchers at Leeds University monitored 100 male competitive cyclists and triathletes and found that almost half had scar tissue building up on their hearts, and nearly 20 per cent had experienced abnormal heart rhythms, called ventricular arrhythmias.

These make the heart’s lower chambers twitch instead of pumping properly, limiting blood supply and raising the risk of heart attack. Another potentially life-threatening risk comes from exertional rhabdomyolysis (or rhabdo). This is damage to muscle cells caused by extreme exercise.

Dr Christopher Gaffney, a lecturer in sports science at Lancaster University, who has studied the condition, told Good Health: ‘Rhabdo is relatively rare, with around 40 cases per 100,000 people a year, but its prevalence has spiralled in recent years.’

Research suggests there has been a 12-fold increase in cases between 2005 and 2015. ‘The explosion of cases has been linked with the increased popularity of high-intensity workouts,’ Dr Gaffney says.

‘The dying cells release proteins into the blood that damage the kidneys, block urine production and cause life-threatening complications such as kidney failure. Most at risk are amateur male exercisers who push themselves too hard, too quickly. The risk of rhabdo can come from abruptly taking up an activity such as rucking.’

The main signs are urine turning brown after an intense workout and extreme muscle pain all the time, not just when you move.

Another complication of extreme exercise is overtraining syndrome, where not allowing your body time to recover leaves your muscles in a constant state of inflammation.

Not only do performance levels plateau, then plummet, it can also affect your health, says Dr Daniel Brayson, 39, a lecturer in life sciences at the University of Westminster.

He personally suffered from this after competing in ultra-endurance cycling events. ‘My training involved doing as much cycling as I could fit around my work – very early mornings and late nights, and also weekends,’ he says.

‘About four years ago, I began to feel heart flutters, minor panic attacks, racing heart and dizziness, and these began to happen with increasing frequency. I felt leaden, and my cycling performance dropped by 30 per cent. I took a year off cycling – time is the only thing known to enable recovery from overtraining syndrome.’

Dr Brayson, who is now researching the condition, adds: ‘I now do a lot less cycling.’

In contrast to the emerging harms of high-intensity exercise, a growing body of research suggests regular moderate exercise can provide the most sustainably significant boosts to our health.

A study in the journal Circulation concluded that adding just five minutes of activity to a daily routine could lower blood pressure and cut the risk of cardiovascular disease by up to 28 per cent.

Lead researcher Dr Jo Blodgett, from University College London, says: ‘Whatever your physical ability, it doesn’t take long to have a positive effect on blood pressure.’

She adds that this included all ‘exercise-like activities, from running for a bus or a short cycling errand’.