KEEPING fit can nearly halve your risk of cancer, a study found.
Data from a million men in Sweden showed staying in shape helps protect against at least nine types of tumours.
Simple fitness like taking the stairs could help prevent cancer
A stronger heart and lungs between the ages of 16 and 25 was linked to a lower chance of neck, throat, stomach, pancreas, liver, bowel, kidney or lung tumours in middle-age.
In the best case, the risk of lung cancer was 42 per cent lower than in unfit people.
Dr Aron Onerup, from the University of Gothenburg, said: “This study shows that higher fitness in healthy young men is associated with a lower hazard of developing 10 out of the 18 cancers investigated.
“These results could be used in public health policy, strengthening the incentive for increasing cardiorespiratory fitness in youth.”
People in the study had their health checked during military conscription between 1968 and 2005 and were tracked for 33 years on average.
It suggests most of the cancers were detected before the age of 60.
Half of Brits will get cancer at some point in their life but polls suggest half of women and a third of men do no exercise.
Meanwhile around 50 per cent of children are active every day and one in three are overweight.
The NHS says adults should do 150 minutes of moderate exercise every week, while kids should aim for an hour of activity per day.
It can reduce cancer risk by maintaining a healthy weight, balancing hormone levels, controlling blood pressure and sugars, and strengthening the immune system.
Writing in the British Journal of Sports Medicine, Dr Onerup added: “Individuals with low fitness were slightly more likely to be obese and had a higher frequency of alcohol and substance abuse.”
People can boost their cardio fitness by fast walking, jogging, cycling, swimming or regularly climbing stairs.