The latest research published in PLOS One Journal (April 26, 2016) showed men who did one-minute of “all-out” exercise on bikes experienced significant improvements in cardiometabolic health measures despite exercising for significantly less time. The length of the study was 12-weeks and the sprint-interval training (SIT) group exercised for 1:00, using a 3×20 second protocol, while the moderate-intensity continuous training (MICT) group completed workouts consisting of 45-minutes of continuous cycling at ~70% HRmax. A 2-minute warm-up and 3-minute cool-down (using 50 watts as resistance) were used for both groups, resulting in 10- and 50-minute sessions for SIT and MICT, respectively.
According to Jenna Gillen, the lead investigator of the study, “the major novel finding from the present study was that 12-weeks of SIT in previously inactive men improved insulin sensitivity, cardiorespiratory fitness, and skeletal muscle mitochondrial content to the same extent as MICT, despite a five-fold lower exercise volume and training time commitment. SIT involved 1-minute of intense intermittent exercise, within a time commitment of 10-minutes per session, whereas MICT consisted of 50-minutes of continuous exercise at a moderate pace.”
Gillen JB, Martin BJ, MacInnis MJ, Skelly LE, Tarnopolsky MA, Gibala MJ (2016). Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment. PLoS ONE 11(4): e0154075. doi:10.1371/journal.pone.0154075
Eric Cressey, Interval Training: HIIT or Miss (2009). Performance and Health Blog.