Interval training — bouts of high-intensity exercise alternated with short rest periods — not only burns more calories than traditional cardio training, but also boosts your body’s ability to fry fat through hormone production.
“[With intervals], you have a greater increase in growth hormone — a fat-burning hormone — and adrenaline, another fat-burning hormone that also helps suppress appetite.”
Not only are interval workouts shorter than traditional cardio training, but they also make you fitter in fewer sessions.
“There are two ways to increase cardiovascular fitness — by increasing the delivery of oxygen to the heart and lungs or by increasing the utilization of oxygen at the muscle level.”
Steady-state works by increasing the oxygen delivery to your heart and lungs. Intervals, however, work on your muscles, helping them use oxygen more efficiently so your heart doesn’t have to pump as much to make them perform.
Jump on a stationary bike and start your own interval training regimen with this guide from Ballantyne:
Start with a regular warmup. When you’ve finished that, pedal at a rate that’s 20 percent harder than your normal cardio intensity. After 30 to 60 seconds, bring the intensity down to a rate that’s half the intensity of a normal cardio workout.
“This is important,” Ballantyne said. “If you don’t take it down to ‘easy’ during the recovery, you’re not doing anything different from a regular cardio workout, and you won’t be able to work hard during the interval portion. You want two extremes: hard and easy.”
Alternate periods of 30 to 60 seconds of hard work with 30 to 60 seconds of easy pedaling for six to 10 intervals to complete your session. As this gets easier, increase the intensity of each interval, work longer during the hard portion, shorten your rest periods or add more intervals. Repeat three or four times per week.