Using the health records of more than a million Swedish conscripts (应征入伍者), a recent study revealed that keeping cardiorespiratory (心肺的) fitness in their late teens and early twenties can cut the risk of developing nine types of cancer by 40% when older. The research team from the University of Gothenburg, Sweden said, "These results could be used to further strengthen the promotion of interventions aimed at increasing fitness in youth."
Almost a third of people aged from 16 to 24 in England aren't physically active, without meeting guidelines of at least 150 minutes of moderate physical activity a week including walking, riding a bike and dancing.
Cardiorespiratory fitness (CRF) measures how well the heart, lungs and linked systems work to get oxygen to muscles during constant activities. The conscripts, aged between 16 and 25, had tests of CRF on exercise bikes between 1968 and 2005. The researchers used Swedish health data to see who went on to have cancer during an average follow-up of 33 years. The study found that increasing fitness was beneficial, regardless of body weight. However, they also found that higher fitness was linked to a higher risk of skin cancer. The researchers explained that this trend might be driven by exposure to sunlight.
Findings from those observational studies provide much evidence for a link between higher levels of physical activity and a lower risk of cancer. However, these studies cannot fully rule out the possibility that active people have lower cancer risk because they engage in other lifestyle behaviors. The researchers cautioned that they had no access to full data on factors such as diet, alcohol intake and smoking and so couldn't fully account for those.
Dr Claire Knight, of Cancer Research UK, said, "The NHS recommends 150 minutes of activity a week, but it's fine to build up activity over time and there are lots of ways to be more active. You don't need to run a marathon or join a gym. Anything that gets you warmer and slightly out of breath and your heart beating faster counts."
