Researchers found that 560 to 610 minutes (roughly 9 to 10 hours) of moderate to vigorous physical activity each week was associated with more than a 30% lower risk of cardiovascular disease.

This is about three to four times the current public health recommendation of at least 150 minutes of moderate to vigorous activity per week.

The findings come from an observational study published online in the British Journal of Sports Medicine.

Researchers from Macao Polytechnic University in China examined how physical activity and cardiorespiratory fitness were associated with cardiovascular disease risk.

The researchers analysed data from 17,088 people enrolled in the UK Biobank between 2013 and 2015.

The participants had an average age of 57, with women accounting for 56% of the group.

Each participant wore a wrist device for seven consecutive days to record their usual physical activity.

They also completed a cycling test that researchers used to estimate their VO2 max, a measure of how efficiently the body takes in and uses oxygen during intense exercise.

The researchers also considered factors including smoking, alcohol use, self rated health, diet, body mass index, resting heart rate and blood pressure.

During an average follow up of 7.8 years, researchers recorded 1,233 cardiovascular events. These included 874 cases of atrial fibrillation, 156 heart attacks, 111 cases of heart failure and 92 strokes.

Participants who met the recommended 150 minutes of exercise per week had an 8% to 9% lower cardiovascular risk.

However, activity levels of 560 to 610 minutes per week were associated with a reduction of more than 30%.

Only 12% of participants reached this higher level of physical activity.

The study also found that people with lower fitness levels may need slightly more exercise than highly fit individuals to achieve similar cardiovascular benefits.

For example, a 20% reduction in cardiovascular risk was associated with about 370 minutes of moderate to vigorous exercise each week among people with the lowest fitness levels, compared with about 340 minutes among those with the highest fitness levels.

The researchers said the findings suggest that future exercise recommendations could consider individual fitness levels instead of relying entirely on a single target for everyone.

The researchers say, "This finding highlights the steeper challenge faced by deconditioned populations."

However, the study cannot prove that higher levels of exercise directly caused the lower cardiovascular risk because it was observational.

The researchers also noted that the participants may have been healthier and fitter than the general population, while fitness was estimated rather than measured directly.

Despite these limitations, the researchers said the current 150 minute recommendation remains a reliable minimum, while higher levels of physical activity may provide greater protection against cardiovascular disease.