With its low cost and accessibility, running is often the exercise modality of choice. Those looking to drop pounds and gain improved metabolic function may want to pick up the pace. A study published online January 28 in BMC Endocrine Disorders (2009; 9 ) provides promising evidence in favor of extremely short duration high-intensity interval training (HIT) as a method for improving insulin action. Study participants included 25 “young, healthy sedentary or recreationally active men” who were placed in an HIT group or participated in a “separate experiment to determine intra-individual variation in response to an oral glucose tolerance test, and did not perform HIT.” The HIT group performed four to six 30-second sprints at maximum effort with a 4-minute rest between exercises six times over 14 days. This accounted for a time commitment of 17–26 minutes and only 2–3 minutes of sprinting per session. By the end of the short study, the HIT group had improved insulin sensitivity by 23%.
“The efficacy of a high-intensity exercise protocol, involving only ~250 kcal of work each week, to substantially improve insulin action in young sedentary [adults] is remarkable,” stated the authors. “This novel time-efficient training paradigm can be used as a strategy to reduce metabolic risk factors in young and middle-aged sedentary populations who otherwise would not adhere to time-consuming traditional aerobic regimes.”