Vigorous exercise protects against breast cancer , less intensive exercises , calories burned

Vigorous exercise

Vigorous exercise does in fact burn a solid amount of fat, frequently more fat than less intensive exercises. It's true that a higher percentage of calories will come from fat during moderate exercise as opposed to intense, but the total number of calories burned from fat during intense exercise can be greater than moderate exercise.

Vigorous exercise protects against breast cancer

While vigorous activity reduced breast cancer risk in normal-weight women, it had no effect in women who were overweight or obese, according to study leader Michael F. Leitzmann and colleagues.

They also found that non-vigorous activity, such as light housework (vacuuming, doing laundry, painting, general gardening) and light sports or exercise (walking, hiking, light jogging, recreational tennis, bowling) offered no protection against breast cancer.

The findings were published in the journal Breast Cancer Research.

"Possible mechanisms through which physical activity may protect against breast cancer that are independent of body mass include reduced exposure to growth factors, enhanced immune function, and decreased chronic inflammation, variables that are related both to greater physical activity and to lower breast cancer risk," the study authors wrote.

"An alternative explanation for the stronger apparent effect of vigorous activity among lean over heavy women is that heavier women may misreport non-vigorous activities as vigorous activities," the researchers added.

Second Vigorous exercise protects

LONDON (Reuters) - Plenty of vigorous exercise can cut a healthy, older woman's breast cancer risk by 30 percent, researchers said on Friday.

A study of more than 30,000 post-menopausal women showed that strenuous activity -- protected against breast cancer even among those who do not have a higher risk, the researchers said.

The effect was clearest among lean women.

"We know that being overweight puts women at increased risk of breast cancer," said Michael Leitzmann, who led the study while at the National Cancer Institute of the U.S. National Institutes of Health.

"What our study shows is that even among women without this increased risk, if they exercise they can get some benefit."

Breast cancer is the leading cause of cancer deaths among women worldwide, according to the American Cancer Society. The group estimates about 465,000 women died of breast cancer globally in 2007, and 1.3 million new cases were diagnosed.

A number of studies have shown that regular strenuous exercise can help people avoid heart disease, cancer and a range of other conditions.

Leitzmann and colleagues used questionnaires to determine how often the women exercised vigorously. All were healthy when the study began.

After 11 years the researchers found that overall the volunteers who exercised most were 13 percent less likely to have developed breast cancer.

The reduced risk was even higher -- 30 percent -- when the researchers compared only women of normal weight, Leitzmann, now working at Germany's University Hospital in Regensburg, said in a telephone interview.

"The relationship was much stronger among leaner women," he added.

Interestingly, non-vigorous activity such as light housework, walking, hiking and easy jogging, did not seem to offer any protection against breast cancer, the team reported in BioMed Central's Breast Cancer Research journal.

The researchers did not look at why exercise may help but Leitzmann noted other studies have shown that working out reduces estrogen levels -- a known risk factor for the disease -- and protects the body's general immune system.