HIIT and moderate intensity training produce similar health benefits

High-intensity interval training (HIIT) - repeated bouts of high-intensity exercise followed by breaks - builds fitness quickly.

Canadian scientists have found that six sessions of high-intensity interval training on a cycle ergometer increased muscle oxidative capacity (citrate synthase) by almost 50 percent, muscle glycogen by 20 percent and cycling endurance by 100 percent. The test subjects made this astonishing progress with just 15 minutes of training within two weeks. This study caused quite a stir in the fitness industry, changing the way many people exercise. Does HIIT offer the same health benefits as traditional moderate intensity training?

A study conducted by Gordon Fischer of the Department of Human Studies at the University of Alabama at Birmingham concluded that HIIT and moderate-intensity exercise have similar effects on aerobic capacity, body composition, insulin sensitivity, blood pressure and blood lipids. 28 physically inactive overweight men trained for 6 weeks with either HIIT or moderate intensity training. The HIIT program consisted of 30-second sprints on a cycle ergometer at 85 percent of maximum effort, while the moderate-intensity training consisted of 45 to 60 minutes of cycling at 55 to 65 percent of maximum effort.

HIIT produced the same changes within one hour per week as moderate-intensity training at five hours per week.

(PLoS ONE, 10(10): e0138853, 2015)