EXERCISE doesn't just help prevent a wide range of illnesses, it can help treat and control them too, as a new study confirms.

Popping out for a regular brisk walk or cycle, and using the stairs instead of the lift, could be as good as popping pills for some conditions.

While it's long been known that physical activity massively reduces the risk of developing certain diseases, a major new study suggests exercise may also be as effective as drugs at treating conditions like heart disease and stroke.

Although people who suffer from such illnesses shouldn't just throw their tablets away, the implication is that regular exercise should be as important a part of their treatment regime as medication.

The new study, by researchers at the London School of Economics, Harvard Medical School and Stanford University School of Medicine, analysed the results of 305 trials involving nearly 340,000 people, comparing the effectiveness of exercise and drugs on preventing death.

It found being active was just as good as medicine for those with existing heart disease, and in the prevention of diabetes, and a more effective treatment than drugs for people who'd suffered a stroke.

Professor Mark Batt, a sport and exercise medicine consultant at Nottingham University Hospitals, says: "Physical activity is extremely important for health, and we know there's compelling evidence for both the prevention of chronic diseases and now in treatment.

"There was already information about how effective exercise is in reducing the risk of developing chronic diseases such as diabetes, stroke, high blood pressure, and also depression, osteoporosis and others, but this study gives more information about its effectiveness as a treatment, and that's really important."

But while physical activity is clearly good for your health on several levels, only 14% of UK adults exercise regularly, and recent British Heart Foundation figures show that only a third meet recommended levels of physical activity.

Part of the problem is, of course, that often it's easier to reach for the pills than it is to exercise. But Batt points out that people don't need to join a gym and make a huge effort to achieve the benefits of being active.

Just taking the recommended weekly 150 minutes of moderate intensity exercise is enough to really make a difference, and this could be achieved through things like walking the kids to school briskly, regularly doing fairly vigorous gardening, or taking the stairs instead of the lift and actively commuting to work.

If you choose to do your recommended 150 minutes of exercise as 30 minutes five days a week, it doesn't have to be done in 30-minutes blocks - it could be three 10-minute bursts a day.

However, you need to feel you've exerted yourself, so a leisurely amble isn't fulfilling the guidelines.

"We're struggling to get enough people to meet physical activity guidelines," says Batt. "Society is partly to blame - we like things to be very easy.

"But this isn't about buying a new tracksuit and running shoes, it's about a lifestyle change that involves things like using the stairs rather than the lift, walking at lunchtime, going dancing, and actively commuting."

Although there's "a mountain of evidence" that physical activity is very good for health, Batt says there's a lack of evidence about the exercise prescription that works best.

"We won't find a perfect dose because we're all different," he explains. "What's right for one person may not be for somebody else."

Nevertheless, simply doing the minimum amount of recommended exercise could bring a wealth of benefits.

For example, after regularly exercising, someone taking a drug for mild high blood pressure might be able to come off it, lose weight and reduce the chances of developing type 2 diabetes and osteoarthritis, and will probably feel a lot better, with muscles in better condition and improved mood and self-confidence.

"There are multiple benefits to this fantastic form of treatment that we haven't invested enough in," stresses Batt.

"What we should be saying is let's get everybody to meet the physical activity guidelines, rather than waiting for a trial to find the perfect dose, which will never happen. There isn't a one-size exercise dose that fits all."

In some cases, exercising instead of taking medication, rather than as well as, may be a possibility, says Batt.

"For many conditions, a lifestyle change that involves improving physical activity levels and reaching the national guidance of 150 minutes of moderate intensity aerobic exercise a week, as well as paying attention to weight, undoubtedly will enable some people to come off medicines for type two diabetes and mild high blood pressure.

"Longer lives and the number of prescriptions written for chronic diseases [going up] is why healthcare's becoming more and more expensive, yet the number of adults exercising is very low," Batt adds. "Exercise can be free or very inexpensive; drugs cost the NHS a lot of money."

How does exercise help?

The reasons behind the benefits of exercise are complex, although part of the benefit is related to exercise burning more calories and thus helping people lose weight, but Batt stresses: "It's much better to be fat and fit than to be completely inactive."

There are, however, many other critical benefits independent of weight loss. For example, fitter people burn oxygen more effectively, and this can occur with relatively small changes in cardiovascular fitness.

"It's really complicated and there's no simple answer," says Batt. "But while it's complex, the message is really simple: physical activity is good for your health."

Personal trainer Greg Small, operations manager for SkillsActive, which runs the Register of Exercise Professionals to regulate fitness instructors, believes exercise stimulates muscle mass and organs, as increasing the heart rate leads to blood moving more quickly around the body.

"Blood is full of oxygen and nutrients, and that's going to feed tissue and muscle and assist in the repair of any problems you've got in them," he says. "I believe exercise's effect on the cardiovascular system can relieve some disease symptoms, and potentially cure them."

Small recommends incidental exercise, like walking the kids briskly to school, walking to local places instead of getting in the car, and moving around as much as possible at work, for those new to exercise.

"You don't have to have a gym membership to reach your exercise and health goals," he promises. "Going from a sedentary lifestyle to going to a gym five days a week - from zero to hero - is something that will make you burn out, it's not going to work for anyone. Doing something is better than nothing, so have a gentle approach initially, and build up slowly.

"Don't assume a prescription medicine will do all the work for you," he adds. "And remember that after exercise you get the release of endorphins, the feel-good chemicals, and a sense of accomplishment that you'll never get from a pill."