People who take regular exercise could reduce their risk of developing around two dozen physical and mental health conditions - including some cancers and dementia - and slow down how quickly their body deteriorates as they age.
An extensive research review, published in the December issue of IJCP, the International Journal of Clinical Practice, says that apart from not smoking, being physically active is the most powerful lifestyle choice any individual can make to improve their health.
Physiotherapist and lecturer Leslie Alford from the University of East Anglia reviewed 40 papers covering the latest international research published between 2006 and 2010.
"The literature reviewed shows that how long people live and how healthy they are depends on a complex mix of factors, including their lifestyle, where they live and even luck" says Mr Alford. "Individuals have an element of control over some of these factors, including obesity, diet, smoking and physical activity.
"Although the focus of my study was on men's health, the messages on physical activity are relevant to both sexes and all age groups."
Health benefits identified by the review include:
• Regular moderate to intense physical activity is associated with decreased risk of coronary heart disease and ischaemic and haemorrhagic stroke.
• A growing body of evidence suggests that increasing physical activity can also reduce the risk of certain types of cancers, osteoporosis, type 2 diabetes, depression, obesity and high blood pressure.
• Evidence of the beneficial effects of physical activity in the primary prevention and management of cancer is growing and there is an association between higher levels of physical activity and lower cancer death rates.
• Research has found that walking or cycling for at least an half-an-hour a day is associated with a reduction in cancer and that when this is increased to an hour cancer incidence falls by 16 per cent.
• Evidence is mixed when it comes to specific cancers. Research has shown a strong relationship between increased physical activity and reduced colon cancer in both sexes. And men who are more active at work - not just sitting at a desk - have lower rates of prostate cancer.
• Other cancer studies show that physical activity after diagnosis can aid recovery and improve outcomes.
• Studies have also shown that men who are physically active are less likely to experience erection problems.
• There is growing evidence that physical activity could decrease the risk of dementia in the elderly.
Recommendations identified by the review include:
• Healthy adults aged between 18 and 65 should aim for 150 minutes of moderate intensity physical activity a week, such as 30 minutes of brisk walking, five days a week. And people who undertake more vigorous intensity exercise, such as jogging, should aim for 20 minutes three days a week.
• Healthy adults should aim for two strength-training sessions a week that work with the body's major muscle groups.
• Older people can benefit from exercise that helps to maintain their balance and flexibility.
• People who are physically active should continue to exercise even when they become middle aged or elderly and those who aren't should increase their physical activity.
• Not smoking and following a healthy diet is also important.
"Ideally, to gain maximum health benefits people should exercise, not smoke, eat a healthy diet and have a body mass index of less than 25" says Mr Alford. "The more of these healthy traits an individual has, the less likely they are to develop a range of chronic disorders. Even if people can't give up smoking and maintain a healthy weight, they can still gain health benefits from increasing the amount of regular exercise they take.
"Physical inactivity results in widespread pathophysiological changes to our bodies. It appears that our bodies have evolved to function optimally on a certain level of physically activity that many of us simply do not achieve in our modern, sedentary lifestyles.
"What is clear from the research is that men and women of all ages should be encouraged to be more physically active for the sake of their long-term health."