Traditional moderate-intensity continuous exercise training (MICT) promotes cardiometabolic health but requires a considerable time commitment, a factor many people often cite as a reason for not exercising. Evidence suggests sprint interval training (SIT) offers similar benefits for insulin sensitivity and heart health as MICT. A 2016 study found that 12 weeks of SIT improved cardiometabolic health as effectively as MICT – with one-fifth of the time commitment.

SIT typically involves short bursts of high-intensity exercise followed by low-intensity recovery periods. It is sometimes described as a “sprint from danger” pace, equating to one’s top running speed, executed for five to ten seconds.

The study involved 27 young, sedentary men who engaged in SIT, MICT, or no exercise (a control group) for 12 weeks. Those who engaged in SIT performed three 20-second high-intensity intermittent exercise sets within a 10-minute cycling session, while those who engaged in MICT performed 50 minutes of continuous cycling exercise at a moderate intensity. Both groups underwent muscle biopsies and body composition analyses before and after the interventions.

SIT and MICT improved peak oxygen uptake by 19 percent, indicating improved cardiorespiratory fitness. In addition, both groups demonstrated enhanced insulin sensitivity and increased levels of citrate synthase, a marker of muscle mitochondria content.

Although this was a small study, its findings suggest that SIT can be an effective and time-efficient strategy to improve cardiometabolic health among sedentary people. The findings also underscore the importance of considering alternative exercise strategies that may be more feasible for people with limited time for workouts. Learn more about SIT in this clip featuring Dr. Martin Gibala.

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