HIIT Me One More Time

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HIIT Me One More Time

Variations of HIIT

For many people, HIIT training is a lot like sex. It’s short, sweet and really gets the heart pumping. Unfortunately sex isn’t as effective at creating a fat burning effect as a session of HIIT is. If it were, the acronym HIITS (High Intensity Interval Training Sex) would be the latest and greatest method to a leaner body and the catch line would read, “have fun while shedding pounds.”

Try to remember the last time you enjoyed a cardio session. It was probably a while ago and consisted of staring at the cute Cardio Bunny on the stair-climber. Well, times change and gone are the days of losing pounds by walking the treadmill, toning your glutes on the stair- climber and/or planting your cheeks on the so-comfortable seat of a stationary bike. If you respect progress, want to minimize muscle loss and maximize fat loss, all that’s required is a ten to fifteen minute session, one to three times a week. That’s the beauty of HIIT.

Let’s face it, humans are creatures who crave change. What was once fun and enjoyable can soon turn into a task that requires the mindset of a Tibetan monk. And if it’s not enjoyable, chances are the routine won’t be performed with much effort or enthusiasm. If you’re one of those individuals who’ve grown tired of repeating the same old routine, let me HIIT you up with some variety, but, first, let’s backtrack a bit.

A Brief Review

For those of you unfamiliar with HIIT, let me briefly explain why it’s so darnned effective at making you a lean bastard.

It’s all about energy expenditure, that is, weight loss. Move more, eat less and you’ll lose body mass. For those of us who carry more muscle than the average person, replacing the body mass with muscle mass is why we make such a big fuss about cardio and it’s catabolic effect on muscle.

For some time now, aerobic work (long duration activity at a steady state) has been known to effectively burn calories and lower body mass because it focuses on using fat as it’s primary energy source. However, as the intensity of activity increases the primary energy substrate involved will shift. The body will move away from mobilizing fatty acids while the proportion of carbohydrates is increased. (1) While this leads to the thinking that long-duration, low-intensity activity is the optimal route towards fat loss, research shows that high- intensity activity is actually more effective. (2, 3, 4) Add intervals of high and low periods (5) and fat-burning increases. There are several reasons for this, and others that remain unknown.

During high-intensity, intermittent training, post-exercise energy expenditure was significantly greater than in subjects who performed moderate or low intensity activity. (6, 7, 8) As a result more fat is utilized in the recovery phase. Several studies confirm that the higher the exercise intensity, the more fat, proportionately, will be burned during the recovery phase. (9, 10, 11) Also, higher exercise intensity had a greater effect on acetyl-CoA carboxylase (an enzyme involved in the fatty acid synthesis pathway) inactivation, which results in greater free-fatty acid oxidation post-workout. (12) Intense interval work also utilizes both the fast and slow twitch fibres, more fast twitch fibres because of the amount of work required of the body in such a short time period. Along with the muscles, the respiratory, heart and nervous system are also required to expend more amounts of energy. This means that more fat and carbohydrates are burned to keep up with the demands of the body both during and after a HIIT workout.

To sum up, the energy cost of HIIT is much greater than that of aerobic exercise. In addition, the body will expend more energy at rest throughout the day and this contributes further to fat loss. This equates to one lean machine if HIIT is properly incorporated into