Research consistently shows that exercise reduces the risk of cancer and heart disease. There is much clinically researched information on the benefits of exercise before, during and after cancer treatment. The message remains the same: inactivity can increase cancer risk and regular physical exercise actually protects against some cancers.
Specifically exercise has been linked to a 40-50% reduction in the risk of developing bowel cancer and a 30-40% reduction in the in the risk of developing breast cancer. Womb or endometrial cancer has also been proven to be a higher risk factor in overweight, inactive women. A study has shown that lean and physically active women experienced fewer deaths from cancer, or cardiovascular disease than other women. In addition, inactive lifestyles can lead to many other health problems, including diabetes, osteoporosis, stroke and heart disease.
So simply put, regular exercise keeps the body weight at a healthy level and being overweight or obese can greatly increase the risk of cancer. But the exercise itself also has a protective effect independent of its effects on bodyweight. People with the lowest cancer risks are those who have healthy body weights and who engage in the most physical activity with all other risk factors being equal.
With just moderate activity menopausal women can reduce their risk of cancer, heart disease and other chronic diseases. Exercise reduces fat deep in the abdomen also known as visceral or intra-abdominal fat. This is a hidden risk factor as it can raise insulin levels which promote the growth of cancer cells and cholesterol levels.
In general women who exercise have a lower breast cancer risk than their sedentary peers due to the lower level of blood estrogen exercise lowers blood estrogen and also reduces cancer growth factors such as insulin.
A study of 40,000 men found that daily physical activity can reduce the chances of getting cancer, or dying from it. It showed that as little as half and hour a day of walking or cycling allowed people a 16% less chance to develop cancer, 34% less likely to die of cancer and 33% more likely to beat the disease.
There is evidence that exercise protects against bowel cancer in a few ways. Physical activity leads to more regular bowel movements and so cancer causing substances pass through the body faster. As with the previous examples exercise lowers insulin levels and other hormones and some growth factors, which at high levels can encourage growth of tumours. Physical activity can also reduce inflammation in the bowel which may otherwise leads to bowel cancer.
How much is enough? Most health organisations agree that 30 minutes of moderate exercise 5 times a week is minimum. This is a great incentive to start now and look to including physical activity more frequently, more intensely, for longer periods of time and throughout your lifetime. And its never too late to start, an American study of over 10,000 men, some who had years of inactivity behind them and took up moderate, regular exercise and reduced their risk of diseases related to inactivity by close to 25%.