A  major study shows prescribing physical activity instead of drugs to certain patients could revolutionise their health.The study is the first to compare the effects of exercise with taking drugs such as statins and beta blockers, which are given to survivors of heart attacks and strokes and are known to cut the risk of dying.The new research analysed previous studies and found no significant difference between the benefits of exercise and drugs for those with diabetes or who have already experienced heart disease.The results were better for stroke victims, who were more likely to avoid death by exercising than taking medication.The study involving almost 340,000 patients was carried out by researcher Huseyin Naci of LSE Health, London School of Economics and Political Science and Harvard Medical School, with US colleagues at Stanford University School of Medicine.He said prescription drug rates are soaring but activity levels are falling, with only 14 per cent of British adults exercising regularly.In 2010 an average of 17.7 prescriptions was issued for every person in England, compared with 11.2 in 2000.Naci said: "Exercise should be considered as a viable alternative to, or alongside, drug therapy.”The research team examined the findings of 305 trials on four conditions: Pre-diabetes, heart disease, stroke and heart failure.Of the studies, 57 looked specifically at the effect of exercise and included 14,716 people.More than 200 trials examined drug treatment for the conditions, such as the effects of statins, beta blockers and blood-thinning drugs on preventing significant illness in those with heart disease.The results published in the British Medical Journal showed exercise was just as effective as drugs in treating those with heart disease and whose blood sugar control suggested they were at high risk of diabetes.But diuretic drugs were more effective than exercise and all other types of drug treatment for heart patients.The findings were most impressive for stroke, with exercise found to be much more beneficial than drug treatment.But Naci said the trials may have included only stroke patients with reasonable levels of fitness, which might skew the results.He said further trials were needed, but added: "We can say the overall trend shows that exercise is better than no exercise and it may enhance the impact of drugs.”He stressed that any patient thinking of taking up exercise should consult their doctor first and should not stop taking their drugs.Dr Peter Coleman, of the Stroke Association, called for more research into the benefits of exercise, but added: "Exercise alone should not be considered an alternative for patients taking prescribed medication.”Amy Thompson, a senior cardiac nurse at the British Heart Foundation, said: "There is limited evidence comparing the effect of exercise to that of drugs. Further research is needed before we can draw any firm conclusions.”