An hour of moderate to vigorous exercise every day can reduce their risk of getting type 2 diabetes by 40%

Walking briskly or cycling for the recommended 150 minutes a week can reduce a person's risk of developing type 2 diabetes by up to 26%, according to new research by UCL and the University of Cambridge.

People who carry out an hour of moderate to vigorous exercise every day can reduce their risk of getting type 2 diabetes by 40%. The study also revealed that any amount of physical activity can reduce the risk of developing the disease.

The research, published in the journal Diabetologia, is the most comprehensive study to look at the impact of exercise, independent of other behavioural factors such as diet, on a person's risk of developing type 2 diabetes.

The UK Department of Health recommends 150 minutes of moderate to vigorous exercise a week, which includes brisk walking, gentle cycling or sports such as doubles tennis. According to the Health Survey for England (2012), as many as a third of adults are not meeting this target.

The study, which analysed summarized data from over a million people, demonstrated that while any amount of physical activity is good for you, the benefits of exercise are greater for people who exceed this recommended level.

The study analysed data from 23 studies carried out in the USA, Asia, Australia and Europe. By combining observations from these studies, the researchers were able to separate out the effect of leisure time physical activity from other behavioural factors, and obtain better estimates of the effects of different physical activity levels.

Previous studies have often included changes to both diet and physical activity, making it difficult to isolate the impact of physical activity alone.

"Our results suggest a major potential for physical activity to slow down or reverse the global increase in type 2 diabetes and should prove useful for health impact modelling, which frequently forms part of the evidence base for policy decisions.," said Andrea Smith (UCL Health Behaviour Research Centre and Institute of Public Health, University of Cambridge), who led the study.

The prevalence of type 2 diabetes is growing rapidly due to rising obesity levels and is estimated to reach nearly 600 million cases worldwide by 2035.

"This research shows that some physical activity is good, but more is better," said Dr Soren Brage, co-author of the study from the Medical Research Council Epidemiology Unit at Cambridge University.

"We already know that physical activity has a major role to play in tackling the growing worldwide epidemic of type 2 diabetes. These new results add more detail to our understanding of how changes in the levels of physical activity across populations could impact the incidence of disease. They also lend support to policies to increase physical activity at all levels. This means building environments that make physical activity part of everyday life.