After age 30, exercising for more than an hour a week may help cut a woman's chances of developing breast cancer, according to a study presented at the American College of Sports Medicine's annual meeting in Seattle.
In the study, Lisa Sprod of University of Northern Colorado in Greeley and colleagues asked 4,296 women to recall their physical activity levels during four key stages of life: 10 to 15 years old, 15 to 30 years old, 30 to 50 years old, and 50 years old and older.
The odds of developing breast cancer did not appear to change in relation to exercise levels between ages 10 and 30, but women above age 30 significantly cut their chances of developing breast cancer if they were more active, the researchers found.
"An average amount of exercise was defined as 60 minutes per week," Sprod told Reuters Health, "so anyone exercising less than 60 minutes was below average, above 60 minutes was above average, and anyone that considered themselves 'highly competitive' chose that category."
Fewer women who classified themselves as "highly competitive" between the ages of 30 and 50 developed breast cancer, compared to women who were less physically active.
Likewise, fewer women who classified themselves as highly competitive at age 50 or older developed breast cancer when compared to women who exercised less than 60 minutes per week.
"Preliminarily," Sprod said, "the take home message is that accumulating greater physical activity after the age of 30 may play a role in reducing the risk of developing breast cancer."
