Survival of the fittest

Cycling

This is a toner and calorie-burner, but women who cycle regularly have another benefit - a 30 per cent reduction in the risk of breast cancer. According to recent research at the University of Bristol you need to cycle - or do any other moderate-intensity exercise - three times a week for 20-30 minutes at a time, to get the benefits.

"Exercise lowers hormone levels which seem to be related to reduced risk," says Clare Stevinson, author of the study, "and also helps prevent obesity, which is a known risk factor."

Hiking

According to researchers at Canterbury Christ Church University College in Kent, hiking can make the heart 10 years younger. Researcher Steve Bird put 56 couch potatoes through an 18-week course of daily walks. They found that longer distances had the most beneficial effects on blood fats and cardiac fitness.

In terms of avoiding heart disease, staying active is even more important that staying slim. Recent research found that people with a low degree of aerobic fitness are 62 per cent more likely to have heart disease than those with a high oxygen uptake.

Rowing

This is one of the most cardiovascularly demanding of sports, but it is also good for your brain. Researchers at Case Western Reserve University in Ohio found that heart-pumping exercise lowers the risk of Alzheimer's disease if done throughout your life.

Supplying the brain with high-grade oxygen and nutrition may also help improve memory, response time and cognitive function in the short term. Researchers at the University of Illinois found volunteers who took three 45-minute aerobic sessions a week saw an improvement in cognitive function of 15-20 per cent in six months.

Running

A recent study found that running gives 12 years' protection from arthritis. It was previously thought that exercise speeds up the rate at which joints wear out, bringing on early osteoarthritis. People who ran six to 20 miles a week saw the greatest benefit.

Skipping

Just 50 skips a day strengthens the skeleton and helps prevent osteoporosis, say the National Osteoporosis Society. One study on men and women aged 50 to 73 found that bone density increased by three per cent after a year of two-to-three keep-fit classes a week that involved jumping exercises. It's the jarring action that helps bones.

Swimming

Swim regularly and you could reduce the risk of developing lung cancer by 40 per cent, according to researchers at the University of Bristol. "Exercise makes the heart and lungs fitter, and has a general immune-enhancing effect that may stimulate DNA repair," says Clare Stevinson. If you don't like swimming don't worry - any cardiovascular exercise is good, and will also help reduce the risk of endometrial and prostate cancers.

Tennis

People who play tennis regularly have a 40-50 per cent lower risk of bowel cancer, recent research found. Exercise speeds up the rate at which the intestines expel toxins and carcinogenic material. "The data suggests that lack of physical activity could be a major risk factor for the disease," says Ken Fox, from the University of Bristol. Tennis wasn't the only moderateto-vigorous activity found to be beneficial - sailing, jogging, golf, swimming and digging are also good.

Walking

As well as protecting against heart disease, cancer and osteoporosis, walking is also one of the best ways to achieve happiness. A Canadian research team found 20-60 minutes of walking, jogging or strength training three times a week as effective as therapy in its mood-boosting effect. And researchers at Duke University in North Carolina found that over-50s with major depression responded better to walking or jogging three times a week than they did to antidepressants.

Golf

Middle-aged golfers are doing more than simply taking a break.

A study of 40,000 post-menopausal women found that golfers (and women doing other light exercise such as bowling or gardening) were in fact adding years to their lives.

The research reveals that those who exercised gently two to four times a week were 30 per cent less likely to die prematurely than those who exercised rarely or not at all.

Yoga

We live in an age of anxiety and stress is linked to many health complaints. Psychologist Jean Twenge of Case Western Reserve University estimates that anxiety levels have risen by 50 per cent in the past 50 years.

Yoga is a great stress reliever, she says, good news for anyone who wants to save their body from headaches, heart disease or the other negative effects of prolonged nervous tension.