High-intensity, high-volume physical activity is not associated with increased all-cause or cardiovascular mortality in men, despite an association with higher levels of coronary artery calcification (CAC), researchers say.

Dr Benjamin Levine of the University of Texas Southwestern Medical Center and colleagues studied nearly 22,000 men without cardiovascular disease from 1998 through 2013.

The baseline mean age was 52. Most were runners, but some were cyclists, swimmers or rowers, and a subgroup trained in all three sports.

High-volume, high-intensity exercise was defined as an activity level greater than 3,000 MET (metabolic equivalent of task)-minutes per week, equivalent to at least five to six hours per week at a pace of about 6.5 minutes per km.