The Benefits Of High Intensity Interval Training
Posted on 14 Mar, 2015
High-intensity interval training (HIIT) has been around for a long time, but it is only of late that it has caught on. The science behind HIIT is pretty fascinating, and so are its benefits. Read on. It could change your life.
High intensity interval training describes any workout that alternates between intense bursts of activity and short periods of rest.
While engaged in an all-out physical effort, your body gets into an oxygen deficit and moves beyond your aerobic exercise zone into an anaerobic one. The anaerobic effect happens when we exert ourselves beyond 84% of our max heart rate.
Anaerobic means "without oxygen," and refers to the body’s ability to produce energy in the absence of oxygen.
Energy for exercise is derived from two primary, dietary fuel sources: carbohydrates and fats. To be converted into energy, fats require more oxygen than carbs. Because of this, as exercise intensity increases and oxygen becomes more scarce, a natural shift occurs where more carbs get burned. Does this mean that HIIT workouts, because they create oxygen deprivation, burn less fat? Not at all, and we will explain shortly.
If fat is the body’s first choice for energy, why do they always say you have to exercise for 30 minutes before fat burning takes place? The answer is simple. During physical activity, it takes about 30 minutes for your working muscles to deplete the fat in your blood. As this happens, there is a hormonal response to restock fat levels in the blood, and your fat cells break down their fat stores and release them into your bloodstream.
When it comes to exercise, finding the time is always an issue. This is why HIIT is appealing in this day and age. Research shows you can achieve more progress in a mere 15 minutes of interval training than someone running on a treadmill for an hour.
Can’t find 15 minutes in the day? With the Tabata training method, you can even complete an effective HIIT workout in just 4 minutes.
Anyone who has been on a diet knows this: that it is almost impossible to not lose muscle mass along with fat.
One of the huge benefits of HIIT is that it ensures most of your weight lost comes from your fat stores, not your muscles. Also, the lean muscle mass which HIIT helps to produce, is metabolically active tissue, and the more of it you have, the faster your resting calorie burn rate will be.
Traditional cardio methods like running are repetitive. The more you perform a single-movement pattern, the more you load up one area of the body, and the more likely you are to get injured. HIIT on the other hand tends to involve different movements: lunges, and sprints, and ducks and dives.
When we train at high intensity with very short rest periods, our metabolism remains elevated for hours and we create what is called EPOC, or excess post-exercise oxygen consumption. In essence, EPOC is an after burn effect (calories burning at rest post exercise) which can continue for more than 24 hours. Also, because HIIT is tougher on the body, it requires more energy to repair itself afterward. And this burns more calories.
One 1994 study at Laval University in Quebec, Canada, found that HIIT was nine times more effective for losing fat than traditional cardio.
A common misconception is that consuming dairy products and taking calcium supplements is all you need to maintain bone strength and density. But the truth is, bones need to be challenged by weight bearing exercise to retain their strength and form. And HIIT does that.
Your ability to transition smoothly from burning fat to burning carbohydrates improves with HIIT. This is particularly useful for sports that may require interspersed bursts of energy, like soccer and tennis.
One 2006 study found that after 8 weeks of doing HIIT workouts, subjects could cycle twice as long as they could before the study, while maintaining the same pace. And according to the American College of Sports Medicine, two weeks of HIIT would amount to the same as six to eight weeks of steady-state endurance workouts.
HIIT improves your blood pressure and VO2 Max (a measure of the maximum amount of oxygen your body can process). But it does more than that for your endurance. HIIT gives you a taste of what it’s like to choke for air, feel the burn, and have your heart feel like it’s going to explode. It increases your ability to withstand pain, breathlessness and fatigue.
If you don’t regularly push your limits, your progress will stall. HIIT is always about identifying your boundaries and then pushing beyond them so that new base lines are set.
High knees, fast feet, squat jumps, burpees. High intensity workouts generally use only your body weight and explosive moves.
Equipment can even work against you during a HIIT workout. Dumbbells, for example, can distract you from your goal, which is to push your heart to the max, not your biceps. Running, biking, jump roping, and rowing, practiced at high intensity, also work great as HIIT workouts. One more great thing. HIIT sessions can be performed anywhere: at home, in a hotel room, at a gym, in a park.
The use of fast muscle fibers during a HIIT session boosts your body's natural production of human growth hormone (HGH), a foundational biochemical that addresses muscle loss and atrophy that occurs with aging. Some studies have shown HGH increases of up to 771 percent, and coupld bring improvements to everything from your skin and hair to your internal organ health.
To some, typical cardio workouts like running are meditative; to others, it’s a bore. High intensity workouts, because of their pace and extremeness, is a more exciting format requiring your full attention. A HIIT minute may feel like an hour, but you definitely will not be bored.
Also, because of the almost immediate fitness gains you make –and will keep making— you will be less likely to be demotivated partaking in HIIT.
[Related article: The Drawbacks Of High Intensity Interval Training]
Great Books For HIIT
by Cathy Wilson
by Sean Bartram
by Michael Matthews