Over the past few years, there has been an increasing trend in the more reliable sources of fitness information to recommend shorter and more intense cardiovascular exercise for the purposes of fat loss. And for good reason: it works! Known as High Intensity Interval Training (HIIT), this method has been widely discussed, so I will not rehash this overmuch; however in the event you are one of the 19 people left who does not realize why you should be doing HIIT, I will touch on the main points.
High intensity intervals (with work portions being 85% VO2max to supramaximal) firstly are shorter, increasing what I will call training economy. Not only do they get you out of the gym faster, but they lend themselves to a greater variety of training methods.
Consider traditional “slow-go” cardio: your options are limited to running, or using a standard piece of gym equipment, most of which are variations on a hamster wheel. On the other hand, with HIIT, you certainly have those options available, but you can also use more fun and challenging things, such as jumping rope or doing lightweight or bodyweight versions of weight training exercise.
More specific to the general theory of HIIT is the principal factor in fat loss: energy deficit. It's become pretty clear that high intensity exercise results in greater caloric expenditure than low or moderate intensity cardio for any given duration. In addition, compared to other training methods, HIIT results in considerably greater Excess Post-exercise Oxygen Consumption (EPOC). The great part there is that EPOC is fueled primarily from the oxidation of fat; therefore, not only are you expending more energy, but more of it is coming from fat.
But wait, there’s more!
High intensity exercise puts an enormous stress on the fast-twitch fibers of the muscles you are using during training; this stress results in those fibers becoming more metabolically efficient. This culminates in your body allowing you to rely more on fatty acids for fuel as well developing greater lactic acid tolerance; overall making you bigger, faster, stronger, leaner, harder…you get the idea.
Furthermore, High Intensity Intervals have a great “afterburn” effect.
That is, because of the aforementioned increase in EPOC (as well as a number of other factors), doing HIIT not only burns a lot of calories during the exercise, but it keeps your metabolic rate elevated for an extended period of time. Just how long? How about up to 48 hours?
Essentially, you can perform a HIIT workout on Monday and still be burning calories from that workout on Wednesday. Obviously, if you perform High Intensity Interval workouts 2-3 times per week, you can walk around with a consistently elevated metabolic rate.
When you factor in the caloric deficit from dieting, as well as your normal weight training, you can see how adding HIIT into the mix will lead to extreme fat loss.
As mentioned, there are a good number of options for the type of exercise you use for this, but just to get you started, I like sprinting.
Since I don’t wanna leave you hanging, here is a quick 12 minute HIIT Sprint workout you can try tomorrow.
Warmup – 4 min jog.
Cooldown: 2 minute Jog, 1 min walk
The number on the left represents your worktime—that is, the amount of seconds you sprint. The number on the right is the amount of time you rest.
Just go to a track, sprint for the prescribed amount of seconds, and for “rest” just slow it down to a walk or very slow jog. When the rest time runs out, kick it back into a sprint. Complete all of the work:rest segments, and finish up with a full sprint for 30 seconds. After that, cool down.
Keep in mind, this is a fairly advanced program, but the great thing about it is that YOU determine how hard it is. Just run as hard as you can. If you can’t keep the pace, don’t sweat it, slow down. Continue with this program twice per week.
If you don’t vomit at least once, I will be either very impressed, or call you a little bitch. Depending on my mood.