Small bursts of activity can slash heart risks for women

Just a few short bursts of vigorous activity each day – such as running to catch a bus or hoofing it up a few flights of stairs – may lower the risk of heart disease complications for women who don't engage in a formal exercise program.

According to a new study of over 22,000 middle-aged people in the United Kingdom, women who were generally sedentary lowered their risk of serious heart events such as heart attack by 45% simply by accumulating three minutes or so of intense activity into their day. Those same three minutes can add up to a 67% lower risk of heart failure as well.

"The fact that we see so strong an association from such small amounts of physical activity is certainly partly attributed to the fact that we have very accurate measurements," study co-author Emmanuel Stamatakis, professor of physical activity and population health and director of the Mackenzie Wearables Research Hub at the University of Sydney, told ABC News.

Stamatakis and his team followed the participants for about eight years. At some point during that time, each was fitted with a wrist device that tracked their every movement for a period of seven days.

Some of the women accrued physical activity at work, during a commute, or at home, though they did not report any meaningful leisure activities or a regular exercise routine.

Even the less-active women who averaged just 1.5 minutes of intense movement daily lowered their risk of serious heart problems, heart attack, and heart failure by 30%, 33% and 40%, respectively, the study found.

However, men who tended towards an inactive lifestyle did not enjoy the same benefits, possibly because men tend to have greater muscle mass than women, as well as other physiological differences. And people who already met the guidelines for the recommended 150 minutes of activity weekly also did not see any heart health improvements from adding the brief spurts of movement, although active men did see a slightly lower risk of stroke.

"The potentially protective effects from short bursts of vigorous activity were much larger in women and it can't be an accident -- there is something behind it … though the study was not designed to understand mechanisms, it cannot give us the 'why' or the reasons behind the findings," Stamatakis said.

Stamatakis added that these findings may be especially helpful for women who don't participate in an extensive workout program.

Adding in periodic bursts of intense activity such as energetic housework, gardening, or a brisk walk to work can go along way towards improving heart health, he said.

Heart disease is the leading cause of death among men and women in the United States, according to the Centers for Disease Control and Prevention.

Esther Zusstone, M.D., is a radiology resident at NYU Langone and a member of the ABC News Medical Unit.