We all know that obesity is an epidemic. The latest figures show that two-thirds of U.S. adults over the age of 20 are considered overweight or obese. Most of us also know that obesity is linked to several chronic diseases like diabetes, hypertension, heart disease, stroke and even cancer. What you might not know is the staggering economic burden of obesity. In 2000, the direct and indirect costs associated with obesity were $117 billion. Since then, those numbers have rapidly skyrocketed. In fact, the 2008 costs associated with just heart disease alone were $287 billion and for diabetes were over $174 billion.

With these staggering numbers, a huge industry has developed for diet and weight-loss supplements. Although few are promising, most of these supplements range from unhealthy to dangerous. So anytime a new study comes out promising miraculous results, I am extremely skeptical. Last week, I came across the study by Babraj et al. in Biomed Central Endocrine Disorders. This study has been widely discussed across the internet as a way to achieve fitness by exercising only 7 minutes per week. Let’s take a closer look at the details to separate fact from fiction.

The study looked at 16 young healthy male volunteers who underwent low-volume high-intensity interval training (HIT). The purpose of the study was to see if doing HIT of no more than 7.5 minutes per week could improve insulin action. The male volunteers performed 6 sessions of HIT over 2 weeks. Each session consisted of four sets of 30 second all out cycling sprints followed by 4 minutes of recovery after each set.
After two weeks of HIT, the men had a 23 percent improvement in how effectively their body used insulin to clear glucose from the blood. In fact, these results were achieved by only expending a mere 250 kcal per week with only 15 minutes of total exercise in two weeks. According to the researchers, the improvements in glucose lasted up to 10 days after the last bout of exercise.

So what do the study results really mean? First of all, the study was NOT designed to come up with a system to lose weight. Remember, you still need a 3500 kcal deficit to lose one pound. The study was also NOT designed to look at improving cardiovascular fitness. You still need to do your cardio. What the study does show is that HIT is a great system to lower your risks of developing diabetes and the dreaded metabolic syndrome. The best use of HIT would be to add it to your current workout routine. The short bursts of intensity may be just what you need to break the monotony and bring a little spice into your workouts.

References:
• Rosamond W, et al.: Heart Disease and Stroke statistics, 2008 Update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 2008, 117(4):e25-e146.
• Babraj JA, Vollaard N, Keast C, Guppy FM, Cottrell G, Timmons, JA. Extremely short duration high intensity interval training substantially improves insulin action in young healthy males. BMC Endocrine Disorders 2009, 9:3.
• Burgomaster KA, Hughes SC, Heigenhauser GJ, Bradwell SN, Gibala MJ: Six sessions of sprint interval training increases muscle oxidative potential and cycle endurance capacity in humans. J Appl Physiol 2005, 98(6):1985-1990.