Relax, it may never happen

You could have the sculpted physique of David Gandy or Madonna if only you exercised enough, couldn’t you? (Or something close.) If it really mattered that much to you, if you dispensed with other priorities like family, career and sleep, and just put in the hours, you could achieve a body that would trigger lust and envy in all who beheld you. You’d also need a great personal trainer, of course, and an exceptionally high boredom threshold to tolerate the endless iron-pumping, plus the requisite self-hatred to make you strive for bodily perfection. That’s it. Disco.

Many of us spend our lives quietly believing that if we just tinkered with our lifestyle, we could be an underwear model. It is perhaps why Men’s Health and any number of women’s magazines sell so well — the possible dream. But although you may not wish to hear it, the sobering truth can save you from this delusion. No need to pant on a treadmill; no point throwing money at the problem. You might as well water a dead plant.

Mounting evidence suggests that for most the dream is not possible: you will never reach the summit of body beautiful. Some won’t even reach base camp. Thou shalt not ‘get ripped abs in 30 days’. Or ever.

The reason is all in the genes. Our physiological responses to exercise — how much fitter we become, how much muscle we gain — are, recent research shows, predetermined. Added to this is further evidence which suggests that how much we are motivated to exercise is inherited, and that our psychological responses to a workout differ too. We do not all punch the air after a spinning class. Some people have the odds of achieving good physical fitness stacked against them. To understand this, we must turn to one of Britain’s foremost sports scientists, Dr Jamie Timmons, professor of systems biology at Loughborough University.

About ten years ago he started noticing that a proportion of people who were put on exercise regimes made no progress whatsoever. Over the next few years his team studied this phenomenon further, both clinically with volunteers and in the genetics laboratory. Although most people do respond to exercise, to what extent they become fitter (which is measured by the efficiency with which their body is able to take oxygen to the muscles) varies considerably.

Only a sixth of us are ‘high responders’, that is, the kind of people who are theoretically capable of achieving a ‘perfect’ body or of becoming an athlete. Most of us lurk in the centre ground, as ‘medium’ or ‘medium-low responders’. And about 20 per cent of people do not respond at all. Yet the government prescribes a one-size-fits-all approach to exercise — 150 minutes of moderate or 75 minutes of vigorous exercise a week — regardless of the fact that a fifth of us will not benefit from this at all.

And there is more depressing news. About 3 per cent of us will become less fit from exercising — our bodies regress. This is a response that Dr Timmons cannot fully explain. ‘The oxygen transport capacity actually goes down,’ he says. ‘The only explanation we have is that somewhere in the system, between the mouth and the muscles — most likely in the periphery of the muscles — they are responding to the training but not adapting properly, making it harder to get the oxygen from the mouth to the muscles.’ He suspects it may be some sort of inflammatory response, but further investigation is needed.

During the course of his research, Dr Timmons has developed a genetic diagnostic test (called XRPredict, £199), which reveals which category you fall into. I took the test. Several weeks later the results came back: I am a medium-low responder, which would explain the frankly pathetic advances I make at the gym. For these genetic differences apply not only to aerobic fitness, but also to muscle gain from resistance training.

‘We’ve tried several different types of training, with different intensity, and they all have non-responders,’ says Timmons. ‘The evidence is these would be low responders to all types of endurance exercise — which covers high intensity sprint training, jogging, swimming, cycling etc. And about 25 per cent of the people don’t gain lean mass tissue when you put them on a 20-week resistance training programme.’ Someone who doesn’t respond to aerobic exercise isn’t necessarily also not going to gain muscle, but it is likely. ‘We published an analysis which showed there are many common features between aerobic and resistance training, in what’s happening at a molecular level, so that suggests to me that if there are processes which are making you a low responder for aerobic fitness, they may also limit your ability to build muscle.’

The chances of you exercising regularly are also not just to do with time, money and circumstance. Motivation is at least partly controlled by genes. The Journal of Physiology recently published a study performed by researchers at the University of Missouri on lab rats. The scientists bred male rats that voluntarily ran endlessly on a wheel with females who behaved similarly. They then bred the least active males with the least active females. Sure enough, the offspring continued the behavioural patterns of their parents. The real discovery, however, was about what was happening in the brains of these ‘lazy’ rats. Briefly put, certain areas in the nucleus accumbens, the part of the brain responsible for reward responses (common to animals and humans), did not mature normally and function properly.

Even more intriguing, however, were the results of the final stage of the study. When they were put on a wheel for a certain period, although the inherently lazy rats ran less, the mere act of exercising increased the neuron activity in that part of the brain. The suggestion, therefore, is that inheritance is not everything — exercise may stimulate more reward responses in the brain and that in turn may lead to enhanced motivation.

Overall the evidence points to this conclusion: how fit, toned or muscular you become will be largely determined by your genes, no matter how much you sweat with a kettle bell. But with this new study suggesting that motivation can be increased (not to mention the general benefits to health and wellbeing of exercise), there is still no excuse for skipping the gym. Sorry.