Exercise – a prescription for health?
Sometimes I bang on so much about healthy living that I bore even myself. The trouble is, the stakes are so high in terms of preventable long-term illness that doctors feel we don’t have a choice. Type 2 diabetes is perhaps the most obvious example. Unlike type 1 diabetes which has nothing to do with lifestyle, changes in your levels of exercise and eating patterns can cut the risk of developing type 2 diabetes dramatically.
Perhaps the best-designed study to show this took three groups of people at high risk of getting type 2 diabetes. One group was given standard advice, and another a tablet called metformin, used to treat diabetes. The last group were given support to make significant changes to their diets, and to exercise regularly, with an aim of getting to four hours a week. After four years, the people in the lifestyle group cut their risk of going on to get diabetes by 58% . In real terms, over three years, for every seven people who engaged in lifestyle, at least one of them avoided a diagnosis of type 2 diabetes if they changed their lifestyle.
Of course, when you’re in a clinical trial you get lots of support – the folk in the exercise group got 2 ½ hours of tailored, supervised exercise classes every week. But even 10 years later, long after the support finished, the people who had been offered intensive lifestyle support were over 1/3 less likely to have type 2 diabetes .
It goes without saying that exercise burns calories, so it can help you lose weight. But there’s much more to it than this. In the Diabetes Prevention Programme, people in the diet and exercise group lost but then regained weight, and the differences in weight between them and the other group weren’t nearly enough to account for the differences in the risk of type 2 diabetes. Exercise doesn’t just burn calories, it reduces your proportion of body fat and increases your muscle tone. It strengthens your heart and protects your joints by increasing the support they get from the muscles that surround them. It protects you against bowel and breast cancer, as well as depression. And recent headlines suggest that on a global level, lack of exercise may account for 5.3 million of the 58 million annual deaths worldwide – about the same number as smoking.
It’s hardly surprising, then, that the government spends much time and effort in trying to get us all to be more active. Now the Local Government Association is recommending that GPs should be able to offer overweight patients ‘green space’ prescriptions. Rather than tablets, they should be giving them gardening sessions or free visits to National Trust properties.
There are lots of ways to get your recommended weekly exercise hit. In recent years, there has been a lot of interest in high-intensity interval training – going all-out in short bursts, as an alternative to moderate aerobic exercise (the kind that makes you mildly out of puff, such as cycling, fast walking, dancing or gentle jogging). You can try a combination of:
- 150 minutes (30 minutes on five days a week) of moderate aerobic exercise, combined with strengthening exercises for your major muscles on two days a week
- 75 minutes of vigorous aerobic activity, combined with the same strengthening muscle exercises
- A combination of the two (eg an hour of vigorous activity and ½ an hour of moderate aerobic exercise), again combined with muscle-strengthening exercises.
Frankly, I don’t care how people get their exercise, just as long as they do. I do know that people perceive exercise as a luxury, and average exercise levels increase with average income . But exercise doesn’t need to be costly – in fact, it doesn’t need to cost anything. Simple measures like getting off the bus one stop earlier and walking the rest of the way to work; using the stairs rather than the lift; helping an elderly neighbour with their gardening once a week. These all add up. Exercising with a friend often counters the temptation to give up when the nights draw in and the lure of the TV becomes stronger.
GPs have had lots of options for ‘exercise on prescription’ over the years – for a couple of years I was able to offer free membership at local council gyms and swimming pools, before the funding was pulled. I know how difficult it is to find time and energy to get out and get active, and I’ll take all the help I can get. I’d love to be able to send my patients off to a National Trust property for free – just as long as they don’t spend the whole time in the tea shop.