Ever wonder why you're still not losing weight when you regularly hit the treadmill for an hour? Or are you simply bored of jogging for 45 minutes straight? Try intervals! Simply put, High Intensity Interval Training (HIIT) is intense periods of work with short recovery segments, allowing you to work at maximum capacity while keeping risk of injury low. The benefits of interval training include time efficiency, increased calorie / fat burn, a healthier heart, increased metabolism and best of all, you lose weight, not muscle.
Pick an exercise, could be anything - running, biking, rowing, skipping, boxing, battle ropes, the list goes on. After a 5-10 minute warm-up, complete 1 minute of high intensity work, followed by 2 minutes at a much lower intensity. Repeat until you've completed 10 to 20 minutes. As time goes on and you improve stamina, you can reduce your rest time to increase the overall intensity of the program.
If you want proof that intervals work, let's take a look at a sprinter. Sprinters are built for power and speed, resulting in a defined physique and increased musculature. The same holds true for professional athletes like hockey players that rely on interval bursts all the time.
So why is interval training preferred by trainers everywhere? Aside from the many benefits listed above, the science behind interval training is fascinating. The human body uses three specific metabolic pathways to provide energy during different activities. The phosphagen system is used during maximum intensity and relies upon the body's store of ATP (adenosine triphosphate - a small molecule in our cells known as the energy currency of life). This system lasts up to 10 seconds before transferring to the glycolytic system, which lasts up to two minutes and uses carbohydrates as fuel. Both of these systems are anaerobic, which means you do not require oxygen (you know, that awesome feeling where you can't catch your breath!). And finally, the oxidative system is used for low-intensity exercise that lasts several minutes, aptly named because you're using oxygen to fuel your activity (making it an aerobic system). This system also uses as fat as fuel.
During HIIT training, your body utilizes all 3 energy systems, and both aerobic and anaerobic processes. During your intense interval, the body quickly calls upon the phosphagen system, and then the glycolytic system carries you through until your "rest" interval, where the aerobic system is used. During your recovery, your body replenishes its ATP stores so that you can repeat the process again and again. It's an exhaustive task for your body, increasing your caloric expenditure. But not only do you burn calories during a HIIT workout, but the effect of all that intense exertion kicks your body's repair cycle into hyper-drive. That means you burn more fat and calories in the 24 hours after a HIIT workout than you do after, say, a steady-pace run.
So next time you jump on that treadmill, don't just tune into the TV for the next 45 minutes while you walk or jog, try intervals! Crank the tunes and kick your butt for the next 10 to 20 minutes and we guarantee you will see results. Remember if you eat like an athlete and train like an athlete, you're going to look like an athlete!