A new study has found that women who exercised in their teenage years were less likely to die from cancer, and have lower mortality rates later in life, regardless of how much exercise they ended up doing as adults.

The research, which was conducted by scientists at the Vanderbilt Epidemiology Centre in the US, focussed on data from the Shanghai Women's Health Study - a large, ongoing study of 74,941 Chinese women between the ages of 40 and 70. The aim was to investigate how exercise in the early part of a person's life can affect their long-term health and mortality, because until now, not much was known about the link.

The participants of the study were recruited between 1996 and 2000, and were asked about their exercise habits during adolescence, including participation in team sports, as well as other lifestyle factors, such as if they went to the gym regularly, or performed any other form of "regular excise", and for how many hours per week. Regular exercise was defined as occurring at least once a week for at least three continuous months.  

The participants were also asked about exercise during adulthood, to investigate whether good exercise habits being carried over into adulthood could be a factor. They were interviewed again every two to three years.

Patricia Reaney at Reuters reports that throughout the study, 5,282 deaths were recorded after an average of nearly 13 years of follow-up, including 2,375 deaths from cancer and 1,620 from cardiovascular disease. "After analysing the data and adjusting for socioeconomic factors in adult life, the researchers found that women who exercised in their teens and as adults had a 20 percent lower risk of death from all causes compared to other women," says Reaney.

The researchers found that being active for just 1.3 hours a week had a positive impact on the women as they got older. They also report that physically active teens had a 16 percent lower risk of dying from cancer and a 15 percent decreased risk of death from all causes.

"Adjusting for birth year and other adolescent factors, adolescent exercise was associated with reduced risk of cancer, CVD, and total mortality," the team reports in Cancer Epidemiology, Biomarkers & Prevention. "Adolescent exercise participation, independent of adult exercise, was associated with reduced risk of cancer, CVD, and all-cause mortality."

While the study did find a statistically significant correlation between teen exercise and lower adult mortality rates, the researchers are yet to confirm a biological process to explain why this might be the case. What's interesting is that while regular exercise being linked to better overall health is a no-brainer, the benefits appear to carry over to adult life, whether or not the exercise itself continues. 

At the very least, says lead author, Sarah J. Nechuta, in a press release, the study should provide motivation for schools and parents to encourage exercise and team sports in school kids, because even if they never figure out the causality, it certainly couldn't hurt. 

"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," she says.