Does high-intensity interval training produce better results?

Short bursts of high-intensity exercises are highly effective and can produce better results than continuous low-intensity workouts, according to a recent study.

During high-intensity interval training, also known as HIIT, a chemical reaction inside the body’s muscles causes athletes to produce more energy and work more efficiently, said researchers from the Karolinska Institute in Stockholm, Sweden.

“Interval training is very good in terms of ‘bang for your buck,’” says Dr. Philip Skiba, program director of sports medicine for Advocate Medical Group in Park Ridge, Ill. “In other words, it’s possible to get a lot of training effect from a relatively small time investment.”

To conduct their research, scientists looked at a group of volunteers who were asked to perform interval training. The training consisted of alternating between different types of vigorous exercises, and allowed time to recover between bursts of action.

The study participants completed six cycles of pedaling as fast as they could for 30 seconds, then rested for three minutes. The repetition made them work harder, but for a shorter amount of time.

“Our study shows that three minutes of high-intensity exercise breaks down calcium channels in the muscle cells,” said professor Håkan Westerblad, principal investigator, in a news release. “This causes a lasting change in how the cells handle calcium, and is an excellent signal for adaptation, such as the formation of new mitochondria.”

In his report, which was published in the journal PNAS, Westerblad said the findings were a first, noting that this form of exercise produced a larger amount of free radicals that hit directly the calcium channels, much more than in conventional exercises.

Dr. Skiba says it’s important to be sure a person is healthy enough for strenuous exercise.

“If you aren’t exercising now, or haven’t been for a long time, it is worth talking to your doctor and getting back into exercise gradually, before really ramping up the intensity,” says Dr. Skiba.