Exercise Less to Burn More Calories

Sprint interval training as weight management strategy

(RxWiki News) We all know that exercise is good for us, but between work or school, taking care of our family and other obligations, we can’t always fit exercise into our daily routines.

A new study shows that only a few minutes of high-power, concentrated exercise will increase calorie burn, despite a shorter amount of time spent doing hard work.

"Try quick bursts of intense exercise to burn more calories."

Kyle Sevits, of Colorado State University’s Food Science and Human Nutrition department, and a team of researchers found that combining quick bursts of high intensity, concentrated exercise with longer periods of easy recovery, exercisers can burn about 200 extra calories!

This practice is called sprint interval training.

The researchers studied five healthy adult male volunteers, aged 25 to 31. To determine that their hearts are healthy enough to participate, each participant performed an exercise stress test. The researchers also studied the volunteers’ body composition and the amount of energy their bodies expended at rest, known as the resting metabolic rate.

During the three days of the study, the participants ate a prescribed diet that controlled their calorie intake so they weren’t over- or under-eating.

After those three days, the participants lived in an enclosed room that regulated air intake and exhaust, and housed equipment to analyze oxygen, carbon dioxide and water content in the air.

This analysis determined the number of calories each participant burned while in the room.

For two days, the volunteers stayed in the monitored rooms, ate the prescribed diet, and participated in low energy activities like using a computer and watching movies.

On one of the days, the participants did a sprint interval workout that involved pedaling as fast as they could on a stationary bicycle set at a high resistance for five 30-second intervals. These bouts of intense exercise were separated by four-minute periods of recovery in which the volunteers pedaled slowly at a lower resistance.

The participants were encouraged to work as hard as they could in the 30-second, high intensity bursts.

The researchers determined that the volunteers burned an average of 200 calories extra on the sprint interval workout day, even though they spent only 2.5 minutes engaged in intense exercise.

Sevits and his research team suggest that practicing brief, intense bouts of exercise can help with weight management, though they aren’t speculating on how these efforts will translate to weight loss.

“Burning an extra 200 calories from these exercises a couple of times a week can help keep away that pound or two that many Americans gain each year,” said Sevits.

Data from this study support sprint interval training as a time-efficient alternative to endurance exercise and a good strategy for managing weight.

“Sprint interval training not only has a higher caloric expenditure than long-slow-distance, given the same length of exercise time, but it also extends the calorie burning process well into the recovery period,” said dailyRx News Contributing Expert Rusty Gregory, a Certified Strength and Conditioning Specialist.

“This is a result of revving up the metabolism in a way that isn't achieved with slower aerobic exercise.”

This study was presented October 10-13 at The Integrative Biology of Exercise VI meeting in in Westminster, Colorado. 

Because the study has not yet been published in a peer-reviewed journal, the results should be regarded as preliminary and still require review by additional researchers in the field. No information was available regarding funding or disclosures.

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Review Date: 
October 11, 2012