The Motor Unit

This article is going to be all about what High-Intensity Interval Training is and implementing HIIT in your training routine. To be clear, HIIT isn’t a fancy way of strength training (although strength training exercises could be a component of the exercises involved), or a series of intense exercises mixed up chaotically and done one after the other with very little recovery in between (that’s a recipe for injury and overtraining, I assure you).

It’s really a way of conditioning your body to repeated high-intensity bouts where your heart rate is expected to reach 80% to 90% of your maximum heart rate with recovery time in between these bouts while helping reduce body fat, improving metabolism, VO2 max etcetera, etcetera. Articles on these benefits of HIIT are aplenty out there but not many on how to correctly implement it.

You typically start off by selecting a movement pattern that is full-body (dumbbell/kettlebell thrusters, burpee variations, kettlebell complexes) or cyclical like running, cycling, kettlebell swings, or even the EFX trainer in commercial gyms and then alternate between high-intensity and low-intensity bouts.

The high-intensity bouts last typically 15 to 30 seconds (sometimes even a few minutes) and then alternated with much longer recovery bouts (45 seconds to several minutes) of lower-intensity exercises to bring down your heart rate but not enough to induce complete recovery before the next high-intensity bout. This is done for a total of 20 to 30 minutes.

The recovery bouts are much longer because during HIIT training you are reliant on your body’s anaerobic fuel reserves that deplete within a few seconds but take much longer to replenish. The recovery bouts are also not too long because when incomplete recovery is induced, the anaerobic system in conjunction with the aerobic system adapts over time by replenishing energy reserves faster.

Now let’s talk about examples. If I take running as an example, the high-intensity bout would be me sprinting for 15 to 30 seconds followed by low-intensity jogging for 45 to 90 seconds and I go about doing this for a total of 20 to 30 minutes one or two times a week during the conditioning days.

In cases where weights are involved like in thrusters, burpee variations, kettlebell swings, or full-body kettlebell complexes there are a couple of caveats that need to be kept in mind -

1. The high-intensity bout involves moving the weights with proper form for as many repetitions as possible covering that duration and then following that with cyclical exercises that do not involve weights like jumping rope or jogging in place for the low-intensity duration.

2. The weight selected for the high-intensity duration should be light enough to be sustainable for the high-intensity bouts across the 20 to 30-minute exercise duration.

I trust this clears up HIIT because I see HIIT being implemented in several commercial gyms and group classes as a way to shock the muscle into growth when it actually is a way to train your energy systems to be prepared for high-intensity bouts.

Until next time!