Exercise may protect against cardiovascular disease regardless of body mass index, according to researchers from Erasmus University Medical Centre in Rotterdam, the Netherlands.

They examined the health records and activity levels of 5,344 adults aged 55–97. Participants were categorized as normal weight, overweight or obese and were also classified by activity level. The study's purpose was to understand associations among weight, physical activity levels and CVD risk.

Over the subsequent 15 years, 866 subjects experienced a cardiovascular event. Those considered overweight or obese with low activity levels were far more likely to experience an event than normal–weight, highly active people. Overweight and obese subjects with higher activity levels did not appear to be at any greater risk of a cardiovascular event than highly active normal–weight subjects.

"Our findings suggest that the beneficial impact of physical activity on CVD might outweigh the negative impact of body mass index among middle–aged and elderly people. This emphasizes the importance of physical activity for everyone across all body mass index strata, while highlighting the risk associated with inactivity even among normal weight people."

The study was published in the European Journal of Preventive Cardiology (2017; doi: 10.1177/2047487317693952).