For an Exercise Afterburn, Intensity May Be the Key

Depending on whom you ask, the answer to this question is either one of the great myths of exercise or one of the great unappreciated truths: Is there an afterburn effect from a workout?

Whether the metabolism speeds up for hours after exercise an old question, first studied a century ago, and over the years, study after study has been carried out, with decidedly mixed results. Some investigators found no post-exercise effect. Others reported effects so small they were almost unnoticeable — one found male triathletes burned just 12 to 30 extra calories after a workout. Others found as many as 700 additional calories were burned after a long and exhausting exercise session.

The latest sally comes in a recent paper in the journal Medicine & Science in Sports & Exercise. Its lead author, Amy A. Knab of Appalachian State University, says it trumps studies that preceded it because of its careful design. And its results are good news — sort of.