When it comes to exercise, intensity is everything, and while a brisk daily 15-minute walk is enough to cut the risk of heart disease, a leisurely 30-minute stroll is not.

Scientists studying data from heart-rate wearables say doing more exercise doesn't do much to reduce your risk from cardiovascular conditions unless it is of at least moderate intensity.

When people did more exercise overall but the amount of moderate to vigorous exercise they did remained the same, there was little improvement in heart health.

The researchers from the NIH Care Research Center at Cambridge add that easy activities such as washing the car or doing laundry, which have counted as exercise in earlier research, are not enough to stave off heart problems.

However, doing just two brisk walks for an hour and fifteen minutes a week or one run for the same amount of time a week is enough to keep the condition at bay.

This is considered the bare minimum for preventing the elevated risk of heart diseases like coronary artery disease and stroke connected with modern sedentary life, and should not be looked at as enough to improve cardiovascular strength.

The study collected data via an activity tracker on the wrist of more than 88,000 middle-aged adults, and followed up on their heart health for an average of around 7 years.

When activity levels doubled there was no significant boost to heart health when the amount of moderate to vigorous activity someone did remained at 10%.

When that vigorous proportion rose by 20% disease risk fell by 23%. When it rose by 40%. disease risk fell by 40%.

Rates of heart disease were 14% when moderate-to-vigorous physical activity accounted for 20% rather than 10% of overall physical activity, even in people who did not exercise much.

This difference is equivalent to turning a daily 30-minute stroll into a brisk 15-minute walk.

Obviously the participants who did the most exercise overall, and did more tough exercise as a proportion of that, had the lowest risk of developing heart disease.

These findings were made from wrist accelerometer data from 88,000 people whose health information is stored in the UK Biobank, a large database containing information about the health of half a million Brits.

Most large existing studies have relied on questionnaire responses to work out how much exercise participants got up to.

However, physical activity levels can be difficult to recall, especially when they relate to low-intensity activities such as washing the car or doing laundry.

"Our findings support simple behavior-change messages that ‘every move counts' to encourage people to increase their overall physical activity, and if possible to do so by incorporating more moderately intense activities," said senior author Professor Tom Yates, of Leicester University.

"This could be as simple as converting a leisurely stroll into a brisk walk, but a variety of approaches should encourage and help individuals to find whatever is most practical or enjoyable for them."

SHARE This Important Finding On Social Media…