HIIT Interval Training — The Full Guide To Fat Incineration [Infographic]
If you’ve never had the pleasure of experiencing a heart-thumping HIIT cardio workout — High Intensity Interval Training – you’re missing out on one of the most effective, high intensity exercise protocols available to the human body. Period.
In my experience, HIIT is the #1 tool when it comes to incinerating the HORRIBLY stubborn body fat that plasters the inner crevices of the abs, specifically the lower abs. HIIT is an absolute beast of a workout, but it’s the fastest, most efficient way to perform cardio, with sessions typically lasting between 10-15 minutes max.
HIIT excels when it comes to preserving hard-earned muscle and zeroing in on body fat. Picture a sprinter vs. a marathon runner. Sprinters — think Usain Bolt or Tyson Gay — are absolutely rip-roaring jacked. Marathon runners are typically lanky and all skin-and-bones. The sprinter body is precisely what HIIT promotes.
If you look at any cardio machine you’ll see a color-coded fat-burning graph that, among other things, shows the “fat-burning zone” as approximately 60-65% of your maximum heart rate (MHR). In theory you DO burn the highest percentage of calories from fat during low intensity, steady state cardio (e.g. long distance running) when compared to higher intensity (anaerobic) cardio. Unfortunately, I really could care less about percentages — I want body fat melting off the body at the highest possible rate.
In practice you burn more overall calories, and ultimately more fat, at a higher intensity. See the chart below for some quick math. What’s more, high intensity cardio — sprinting in particular — uses very little muscle tissue for energy; long distance cardio tends to sap valuable muscle tissue and extracts amino acids to generate fuel. Yuck.
HIIT also elicits a response known as EPOC (excess post-exercise oxygen consumption — highlighted in-depth here), which boosts base metabolism, calorie burn, and the rate of fat loss for up to 48 hours post-workout. You’ll actually burn A LOT MORE calories when you’re on the couch, working, sleeping, etc. as a direct result of a HIIT workout.
Sorry, you don’t get anywhere near as much EPOC from long distance running (but you do from weight-lifting).
In terms of health & performance benefits, HIIT is about as beneficial as it gets. It significantly increases power, fat oxidation, and V02Max — the maximum amount of oxygen the body can consume during exercise, a measure of all-around cardiovascular fitness; improves cholesterol, blood pressure, and triglyceride profiles, two measures of heart health; and enhances insulin sensitivity, a major determinant of diabetes.
How Does Interval Training Vary?
While many different types of interval training exist, at the core it simply implies varying the intensity of a workout at a calculated rate. Interval training can differ in the following ways:
- Mode – Type of equipment or terrain used (e.g. treadmill, bike, weight-lifting, running on a track)
- Intensity – Level of speed, length of rest period, or weight/resistance used (e.g. speed on the treadmill, weight used, rest period, resistance on a bike)
- Ratio – Ratio of time in the low-to-high intensity intervals (Walk 90 seconds, sprint 45 seconds = 2-to-1 ratio low-to-high. Walk 30 seconds, sprint 30 seconds = 1-to-1 ratio low-to-high)
- Duration – Number of intervals/length of the entire workout
Sample HIIT Workout
For the Lean It UP version of HIIT cardio, we’ll use a 2-to-1 low-to-high ratio for 15 minutes total –
Walk 2 minutes as a warm-up (3 MPH)
High Intensity Interval 1: 45 second all-out sprint. Sprint speed is going to vary on a person-by-person basis. I sprint at 12.5 MPH — choose a level that’s intense and makes you run HARD, but at the same time make sure it feels safe. Start conservative and gradually work your way up over time.
Low Intensity Interval 1: 90 second walking rest interval (3 MPH)
High Intensity Interval 2: 45 second all-out sprint
Low Intensity Interval 2: 90 second walking rest interval (3 MPH)
Repeat 3 additional intervals
2 minute walking cool-down (~2.5 MPH)
As a word of caution, this version of HIIT is extremely taxing on the body — only attempt it if you’re in the physical shape to handle a highly intense regimen. Regardless of who you are, start with a conservative intensity and gradually progress to higher speeds.
For more information on HIIT see the infographic below from The Greatist, which does a nice job laying out the foundation of interval training and a few different variations, including: Tabata, The Little Method, and Turbulence Training.
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