Read this (or really any) fitness magazine, and you’ll find plenty of articles touting the multitude of benefits to be gleaned from high-intensity interval training, or HIIT. In fact, elsewhere in this issue we have an article about exactly that. Indeed, science has revealed that shorter, more intensive bouts of activity interspersed with slower-paced recovery increases fat burning both during and after the workout, and boosts a range of cardiovascular health benefits.
So are you crazy for even considering putting on your headphones and hopping on a treadmill for a good, old-fashioned 60-minute jog? According to our experts, absolutely not.
On the Rebound
“Steady-state cardio is a great active recovery tool,” says Mary Edwards, MS, CSCS, ACSM, the fitness director and professional fitness trainer at Cooper Fitness Center, part of Cooper Aerobics Center in Dallas. “If you’re doing HIIT all the time, you’re in danger of overtraining and undoing all your hard work. Steady-state is a great, low-intensity way to improve circulation, [which] can help with the healing process.”
Using longer, slower cardio as an active recovery protocol can help remove the metabolic waste products from your muscles that contribute to soreness and also can help lube joints to improve your range of motion and mobility. It also allows you to get in some activity and burn some calories on a day when you’re simply too tired/sore/hungry to do a HIIT workout.
When we do cardiovascular exercise, whether steady-state or interval training, we burn a combination of carbohydrates and fat. “Within 10 to 15 minutes, the body shifts and the percentage of fat used as fuel increases,” Edwards says. “Much of this is based on your fitness level: The more fit you are, the more efficient you are at burning fat and calories.”
What’s more, the postworkout calorie burn for the two exercise types are different — but not extremely so. According to one study published in the November 2016 issue of The Journal of Strength and Conditioning Research, active men participated in three exercise protocols: four 4-minute HIIT intervals at 95 percent max heart rate, six 30-second sprints and 30 minutes of steady-state cardio at 80 percent MHR. Three hours postworkout, the total oxygen consumption and energy expenditure (overall calorie burn) was not significantly different between the steady state and the HIIT protocols.
HIIT delivers more overall fat-burning benefits than steady state, but our point is that steady state burns fat and calories too, and it makes sense to keep it in your rotation, both as an active recovery tool and as a mental break from the intensity of HIIT workouts.