Bonking is, of course, slang for running out of energy during exercise. It usually happens when the working muscles run low on glycogen, which is the body's limiting fuel source for sustained activity.

Bonking is something you'd never want to do on purpose. Or would you?

Believe it or not, one highly respected exercise scientist has suggested that it may be beneficial to bonk regularly in training. Her name is Bente Klarlund Pedersen, Ph.D., and she's a researcher at the University of Copenhagen, Denmark.

Klarlund recently explained her rationale for "intentional bonking" in a lecture entitled "Signaling the Muscles to Adapt: Train Low, Compete High?" which was delivered at the 53rd Annual Meeting of the American College of Sports Medicine.

Benefits to under-fueling workouts

In this provocative lecture, Pedersen made the case that athletes -- and especially endurance athletes -- stand to gain greater fitness by performing some of their workouts in a glycogen-depleted state than by trying to perform all of their workouts in a glycogen-replete state.

In practical terms, she said, they should do some workouts within hours of having completed their last workout, such that there's not enough time to replenish muscle glycogen stores between workouts, and they should also leave their sports drinks and gels at home for some workouts (that is, intentionally under-fuel their muscles during training).