“Lack of time” is one of the most commonly perceived barriers to training. Maybe that’s one reason why high-intensity interval training (HIIT)—and its ability to efficiently deliver results—is popular among all age groups and fitness levels. Beyond its convenience and efficacy, research shows HIIT benefits health as well.

Published in The Journal of Physiology (2021; doi:10.1113/JP281210), a topical research review of 11 “low-volume” HIIT studies found that active interval workouts that take less than 15 minutes—not including rest periods, warmups or cooldowns—can offer significant health benefits related to blood sugar control and metabolic and heart health.

For example, in another study by the same authors, participants who did 4 minutes of HIIT three times per week for 12 weeks significantly improved blood sugar levels, liver fat and cardiorespiratory fitness. Each workout consisted of a 10-minute warmup, 4 minutes of cycling at a rate equivalent to 90% of VO2 peak, and a 5-minute cooldown at 50% of VO2 peak. Study authors found the health improvements were comparable to those experienced by participants who did 45 minutes of moderate-intensity aerobic exercise (Diabetes Care, 43 [10], 2371–78).

“While the WHO guidelines may serve their purpose at a populational level, individualised and tailored low-volume HIIT interventions delivered by appropriately trained exercise professionals may be more effective at an individual level, especially for time-poor individuals,” said lead study author Angelo Sabag, PhD, postdoctoral research fellow at NICM Health Research Institute, Western Sydney University. “This research is especially important now as people are looking for new and exciting ways to engage in regular exercise, after a year of lower physical activity due to the pandemic.”

See also: 60-Second HIIT Beats 30-Second HIIT