Sometimes the immediate benefits of exercise - extra energy or a sense of accomplishment - are better motivation to exercise than long-term gains such as protection against chronic diseases. But, whatever the incentive, being physically active throughout one's life is good for health. Canadian researchers recently added further support to a long-term benefit of exercise for women with some new findings that a lifetime of physical activity may minimize the risk of developing breast cancer.

This study involved about 2400 women, half of whom had been diagnosed with breast cancer. Researchers questioned them about their current and past health and lifestyle habits including menstrual and reproductive histories, alcohol consumption, smoking habits, diet, cancer history, and physical activity patterns throughout their lives. The volunteers were given specially designed calendars and the interviewers were trained in techniques to help prompt their memories.

Exercise benefits older women

The researchers found that physical activity did not alter breast cancer risk among younger, premenopausal women. But later in life, physical activity appeared to make a difference. The most physically active postmenopausal women decreased their breast cancer risk by 30%. And adding other health-conscious measures was even more beneficial. Those women who abstained from smoking and alcohol in addition to leading active lives reduced their risk of breast cancer by as much as 70%.

Researchers offer several explanations as to how physical activity might reduce breast cancer risk. It may be that increased physical activity helps keep weight under control as one gets older, or that exercise strengthens the immune system. Or, it may minimize the levels of certain hormones that circulate throughout the body.

This study supports numerous others showing that physical activity decreases the risk of breast cancer. But there are still inconsistencies as to who is most likely to derive this benefit - younger or older women, smokers, those that are overweight, or who have had fewer children. Although this study teases out some of those factors, more research is needed before the mechanism is fully understood.

Begin a lifetime of activity any time

What is becoming more apparent is that many types of physical activity offer health benefits - from walking and aerobic exercise to gardening and even housecleaning. In fact, most of the cancer protection in this study was a result of job-related or household activity. The key is consistency, not necessarily the total amount of calories expended. Although the greatest reductions in breast cancer risk were noted in women who had been physically active over a lifetime, don't let that discourage you. It's never too late to start!