reposted from: Bandolier - full article posted below, unedited. "The bottom line is that women who walk briskly or exercise vigorously for three hours a week or more can reduce their risk of heart disease."
Women should walk
A new analysis  sought to pin down the relationship between coronary heart disease and exercise in women. In Japanese men, a study showed that regular walking decreased mortality ( Bandolier 50 ).
Detailed information on physical activity was first collected in 1986 and updated in 1988 and 1992. This included various forms of vigorous and non-vigorous exercise, plus a walking history that included their walking pace: easy or casual (less than 2 mph), average (2.0 to 2.9 mph) or brisk (more than 3 mph) [note that 1 mph = 1.6 kph]. A weekly metabolic-equivalent (MET) was calculated for the various forms of activity. Total MET hours per week was then calculated.
|Activity||MET per hour|
|Vigorous||more than 6|
|Nonvigorous||less than 6|
|Walking||2.5 to 4.5, depending on pace|
|a MET is the caloric need per Kg per hour of activity divided by the caloric need per Kg at rest|
When adjustment was made for these factors there remained a significant association between higher levels of total physical activity and reduced risk of a coronary event (Figure 2). There was a 34% reduced risk for the highest total activity quintile.
Figure 2: Relative risk of coronary event for each quintileSignificant reduction in quintiles 4 and 5
In women who took no vigorous exercise, brisk walking had a similar effect on reducing the risk of a coronary event (Figure 3). Using women who walked at a casual or easy pace as a baseline, women who walked briskly reduced their risk by 36%. Compared with sedentary women, women who walked briskly for 1 to 3 hours a week had a risk reduced by 30% (95% CI 5 to 49%) after allowing for other factors.
Figure 3: Relative risk of coronary event by walking pace for women who did not take vigorous exercise
This is another study linking increased physical activity to better health. Importantly this study is one of the biggest to examine the effects of exercise in women. The bottom line is that women who walk briskly or exercise vigorously for three hours a week or more can reduce their risk of heart disease. ImpAct 3 examined a visionary scheme for prescribing walking exercise.
Bandolier 50 had reports of walking reducing coronary and all cause mortality in retired Japanese men in Hawaii, and of exercise reducing death rates in a Finnish twin study. The benefits of moderate exercise have been known for some time, and the evidence continues to accumulate. The size of the effects continues to impress, and just shows that evidence-based healthy living is something upon which we should concentrate more.