Listen to the standard weight loss advice and you might assume long cardio workouts are unavoidable. After all, it’s common for fitness experts to recommend spending 60 to 90 minutes a day jogging, biking or doing other forms of cardiovascular exercise. If you’re not a fan of long workouts, you’ll be glad to know you have another option: high-intensity interval training or HIIT. A HIIT workout can be as short as 10 minutes yet provide even greater benefits than longer, slower-paced workouts. HIIT workouts hold the potential to improve your cardiovascular fitness, lower insulin resistance, and even help you build muscle mass.
Shorter doesn’t necessarily mean easier, though. Typical low- to moderate-intensity cardiovascular exercise means working out at 60 to 70 percent of your maximum heart rate (MHR) for at least half an hour. In fitness terms, this is known as steady state cardio. It’s the kind of monotonous exercise you can get jogging on a treadmill while watching TV. HIIT cardio, on the other hand, involves brief intervals of high-intensity exercise performed between recovery periods of lower-intensity exercise. For example, you might sprint at your top speed for 30 seconds, then walk for 1 minute and repeat that cycle for 15 minutes. The high-intensity periods can raise your heart rate to as much as 90 percent of your MHR or more, meaning they take your full concentration.
Burn Fat Faster
Doing an hour of moderate cardio a day probably will help you slim down, but it’s not the most efficient strategy. A review of recent research, published in the Journal of Obesity in November 2010, found HIIT appears to be more effective for reducing body fat than other types of exercise, including steady state cardio. [1] Exactly why HIIT works better is still up for debate, but one reason may be its effect on your metabolism. HIIT workouts raise your metabolic rate, the rate at which you burn calories while at rest, more than slower cardio and keep it raised longer.
Shorter workouts have other advantages, too. If you’re trying to squeeze exercise into a busy schedule, it’s easier to find 15 minutes for a workout than 60 minutes. Motivation’s also easier to come by when you know you won’t be chained to your treadmill or elliptical for half an hour. Put together, these facts may make you more likely to actually do all your planned workouts rather than skip them when you’re short on time or ambition.
Muscle Up
When you already have a fairly low body fat percentage, too much cardio can wear away at your hard-earned muscle mass. By cutting the length and increasing the intensity of your workouts, you can trim off any excess fat without losing healthy muscle mass. It gets even better, though. HIIT may also help you build muscle, according to a study published in the February 2009 issue of the Journal of the International Society of Sports Nutrition. [2] The young men participating in the study followed a 6-week HIIT program while supplementing their diets with the amino acid beta-alanine. By the end of the study, the men had put on an average of 2 pounds of muscle.
Planning Your Routine
High-intensity interval workouts aren’t complicated, but they aren’t something you want to jump into without planning. If you’re not in the best of shape or you have any health issues, check with a health care professional before you venture into HIIT. Keep in mind that the definition of “high” and “low” intensity depends on your current level of fitness, so it varies from person to person. Your own feeling of exertion is the easiest way to tell the difference. During your high-intensity periods, you should be working as hard as you can. When you rest, take only as long as you need.
Remember, you’ll also need about 5-minute warm-up and 5-minute cool-down session along with your main workouts. To give your body time to recover between workouts, keep your sessions to four a week or fewer. Performing HIIT more often than that puts you at risk for overtraining.
You don’t have to knock yourself out to benefit from these workouts. Even very short bursts of high-intensity exercise can improve your health, suggest results from a study published in the European Journal of Applied Physiology in July 2012. [3] In this study, previously sedentary adults followed a 6-week reduced-exertion HIIT routine, performing three 10-minute workouts each week. Their workouts consisted of low-intensity cycling with two short “sprints,” which started at just 10 seconds and gradually increased to 20 seconds over the course of the study. After 6 weeks, study participants had greater aerobic capacity and improved insulin sensitivity despite reporting relatively low feelings of exertion.
Running and cycling aren’t your only options for HIIT workouts. Any type of cardiovascular activity that lets you control your intensity is fair game. That includes swimming, jumping rope, many types of dance, and exercise on cardio machines like the elliptical, rower, and stepper. I’ve also made numerous workout videos using the HiiT principle that you can do in the comfort of your home, including Crossfire, To The Max, Afterburn, Cardio Supersets and HiiT. My new XTrain workout series will also utilize HiiT training along with metabolic conditioning and classical heavyweight strength training for a complete 90-day fitness program.
If you’ve had enough of long hours mindlessly peddling a stationary bike with little to show for your effort, give high-intensity interval training a try. With these workouts, you not only stand to burn fat faster, but you could improve your heart health and build muscle mass, too.
References:
[1] ncbi.nlm.nih.gov/pmc/articles/PMC2991639/ [2] jissn.com/content/6/1/5/ [3] ncbi.nlm.nih.gov/pubmed/22124524
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LOVE LOVE LOVE these reminders that I have to keep HIIT in my workout rotations!!
I did not know that HIIT improves insulin resistance, well, that clinches it: I am always going to have at least one of those blistering workouts at least 1x/week. That said, when I was doing shorter, more intense workouts, I found that it wasn’t as effective on the fat loss front than doing a steady state workout at 80 percent of max for 45 to 60 minutes. I wonder if that has something to do with the total calories burned. Of course, it might just be another one of those ‘ymmv’ situations.