Study: speed intervals help older runners

A new study suggests that speed work might be more beneficial for recovery and maintaining muscle mass than a steady state run. These findings are particularly important for masters runners, who begin to struggle with maintaining strength and have their recovery times lengthened with age.

Researchers at the University of North Carolina published their findings in the Journal of Endocrinological Investigation in December. They evaluated 15 subjects , all seasoned runners. Each participant was asked to alternate between a 45-minute easy to moderate effort run and a workout of the same length that involved 90 second spurts of sub-5K speed and 90 seconds of recovery.

The subjects’ testosterone levels were measured before and after the run, as well as 12 hours later. Firstly, researchers found that both activities increased the subjects’ testosterone levels from not exercising at all. Secondly, the speed session caused a much larger boost in testosterone than the steady state run. And finally, that testosterone was metabolized 12 hours after the intervals, but not after the easy run.

Their findings are potentially good news for older runners because more effective testosterone metabolism vastly aids in recovery and maintaining muscle mass — two factors that are crucial for masters runners.