Teenage girls who take part in regular exercise are significantly less likely to die from cancer when they are middle-aged, researchers have found.

The findings are a stark illustration of how a sedentary childhood has an impact on health later in life.

Exercising for just one hour and 20 minutes each week while a teenager resulted in a 16 per cent reduction of the risk of dying from cancer aged 40 to 70, the study found.

Death from all causes - including heart attacks and strokes - was reduced by 15 per cent, according to the researchers.

NHS guidelines recommend that adults perform at least two hours and 30 minutes of exercise a week.

And they say that children and teenagers aged five to 18 should be even more active, performing at least an hour of physical activity or play each day.

The new research, led by experts at Vanderbilt University in Tennessee, U.S., suggests that even moderate activity in the teenage years can have a lasting impact.

The researchers examined health data from 75,000 Chinese women aged 40 to 70, who were asked how much they had exercised as teenagers and then monitored for 13 years.

The findings, published in the journal Cancer Epidemiology, Biomarkers and Prevention [must credit], found that those who had taken part in regular exercise between the ages of 13 and 19 were less likely to die in their 40s, 50s or 60s - particularly from cancer.

Those who carried on that exercise pattern into their adult life had an even lower chance of dying – a 20 per cent reduction – in middle age.

Lead author Sarah Nechuta said: ‘In women, adolescent exercise participation, regardless of adult exercise, was associated with reduced risk of cancer and all-cause mortality.

‘Our results support the importance of promoting exercise participation in adolescence to reduce mortality in later life and highlight the critical need for the initiation of disease prevention early in life.’