Exercise and sleep cut cancer risk

In a long-term study of nearly 6,000 US women, researchers found that those who exercised the most had a 25 per cent lower chance of developing cancer than those who were the least active.

But among younger, physically active women, those who slept less than seven hours a night had a 47 per cent higher risk of being diagnosed with cancer than those who regularly got a good night's rest.

Insufficient sleep has been linked to high risks of developing a number of conditions including heart disease, obesity and diabetes but, again, researchers have not determined exactly how sleep prevents disease.