HIIT or High Intensity Interval Training is hot and for good reason.  If done correctly, it is the best possible cardiovascular training regimen known.  It provides cardiovascular improvement (as measured by oxygen intake), performance gains for athletes (endurance and speed, in particular) and maximization of post-workout calorie burn and metabolism all in a relatively short workout session.

The proof is in the studies.  Every study comparing HIIT-based workouts to other cardiovascular workouts – such as steady-state running or traditional interval training – shows these cardiovascular, performance and metabolic improvements are realized quicker and at a higher level by those engaged in HIIT.  In addition, because HIIT also tends to use strength training exercises and plyometric-based moves it’s an anaerobic workout within an aerobic format.  Therefore, HIIT also produces measureable results in bone density and muscle strength and explosive power.

Though HIIT’s place in the mainstream of the fitness industry is relatively new, the first study on HIIT was performed in Tokyo in 1996 by Dr. Izumi Tabata.  The formula for the workout became known as the “Tabata Protocol” and is now known simply as Tabata.  The Tabata Protocol is short intervals of high intensity exercise followed by relatively longer intervals of rest, thus the name High Intensity Interval Training or the acronym HIIT.  Workouts are usually marketed as either Tabata or HIIT.  CrossFit, while not technically the Tabata Protocol, uses much of the philosophy behind HIIT in their workouts.

So, now you’re probably thinking this is all too good to be true, there must be a downside. Well actually, it’s not too good to be true…as long as certain criteria are met:

• Conditioning Appropriate: While most of my workouts are appropriate for everyone from novice to advanced, HIIT is not one of them.  It isn’t appropriate for the novice or deconditioned exerciser.
• Proper Form: HIIT workouts are difficult, very difficult.  Your muscles will tire quickly.  It’s imperative for injury prevention that you know how to perform the individual exercises within the workout with perfect form at a moderate pace before you try them at a high intensity.
• Appropriate Length and Frequency: Because HIIT is taxing on both our anaerobic and aerobic systems, more is not better than less.  A single HIIT workout should not exceed 20 minutes in length and no more than two HIIT workouts should be performed per week and never on back-to-back days.  Failure to adhere to these guidelines will result in overtraining problems, negating any positives you would otherwise realize.
• Proper Fueling and Hydration: Never perform this workout on an empty stomach.  It’s best to consume easily digestible complex carbohydrates and proteins approximately 90 minutes prior.  Post-workout, the name of the game is proteins.  Complete proteins are best – meats, fish, dairy, eggs and soybeans.  You can also supplement complete proteins with partial proteins such as beans, nuts and seeds.  Hydrate before and after your workout as you would for any high intensity or endurance workout.
• Appropriate Environment: I recommend doing this workout indoors in a temperature and humidity controlled environment.  If possible, have fans blowing on you to aid your body in temperature control.

If you meet the criteria and are ready to get started, bravo!  Here’s everything you need to know:

The Bouts: Each HIIT workout is represented by this formula:

X Bouts(Interval = 1Work:2, 3 or 4Rest)

How many bouts (X) you do depends upon the length of your intervals, keeping in mind that you want to keep the total workout at 20 minutes or less.

The Intervals: The interval ratio recommended for someone starting a HIIT program is 1Work:4Rest.  For example, a common starting point for HIIT is: 10 bouts of 20 seconds of work to 80 seconds of rest intervals.  In this case, each interval would last 100 seconds (20 seconds of work + 80 seconds of rest).  You would perform this interval 10 times (10 bouts) for a total of 1000 seconds (or about 17 minutes).

The Work: The work should be an all-out effort.  You shouldn’t be able to carry on a conversation during your work intervals.  During the work interval, you’re going as fast as you possibly can while maintaining that pace for the entire length of the work interval.

The Rest: The rest interval is just as it suggests, it is rest not recovery.  While traditional interval training has one performing the work at a slower pace, known as the recovery interval, the rest period for HIIT is true rest.  (Trust me, after performing your first few bouts of a HIIT workout, you’ll have no trouble resting during the rest period.)

The Exercises: The original Tabata workout had participants going through a handful of bouts of a few different exercises.  For example: 5 bouts of 20:80 second push-ups followed by 5 bouts of 20:80 second squats.  I personally like to cycle through exercises from one bout to the next, kind of like a circuit training format, so that I can keep it interesting and less repetitious.  For example: 1 bout of 20:80 squats + 1 bout of 20:80 jumping jacks + 1 bout of 20:80 burpees + 1 bout of 20:80 explosive punches + 1 bout of 20:80 lunges repeated in sequence a second time for a total of 10 bouts.

The HIIT Workout

Warm-Up: Take 2-5 minutes to warm up the muscles and ease your heart rate into the workout by doing some moderate cardio.

Perform HIIT: Using a Tabata timer or app, perform 10 Bouts of 20 seconds of Work followed by 80 seconds of Rest.  Plyometric maneuvers, calisthenics and strength training exercises work best.  You can choose which exercises to do, how many bouts of each and the sequence based on your preferences and training goals.  Avoid the use of cardio machines and external load as they make it difficult to quickly reach maximum speed for short intervals.  Examples of common exercises used during HIIT:

• Push Ups
• Jump Rope
• Jumping Jacks
• Burpees
• Squats
• Lunges
• Mountain Climbers
• Power Punching (rapid air boxing)
• Power Kicks (rapid forward or side kicks; can be done with or without hopping on standing leg)

Progression: If you are doing these regularly, eventually you’ll want to progress your intervals.  Begin by shortening the rest interval (1Work:3Rest or 1Work:2Rest) while increasing the number of bouts accordingly.  When you’re ready to progress a 1Work:2Rest interval, increase the amount of time for your work interval and return to a 1Work:4Rest ratio and lower the number of total bouts accordingly.

Flexibility Training: No workout is complete without appropriate stretching.  The following provides a full-body flexibility regimen to end your HIIT workout – hold each stretch for 30 seconds:

• Standing Chest Stretch: exercise provides progression for deeper stretch
• Overhead Triceps Stretch: stretches arms & shoulders (stretch both sides)
• Standing Triangle Straddle Bends: stretches back, waist & outer thighs (stretch both sides)
• Kneeling Hip Flexor Stretch: stretches hip flexors & quads (stretch both sides)
• Seated Toe Touches: stretches back, glutes, hamstrings, calves & shins

Author’s Note: Always consult your physician before beginning any new exercise program.

Fit&Happier Workout of the Month defined:  These are 30 minute general fitness workouts designed to offer a complete and balanced approach to strength and cardiovascular training in the most efficient way possible.  Strength training workouts will each feature a different form of resistance, or load, so that you can choose the type of resistance based on equipment availability and your preference.  These will offer full-body strength training and muscle toning with base exercises appropriate for beginners and progressions for those more experienced in strength training.  Cardio workouts are designed to get the most calorie burn possible in the time allotted.  Combo workouts combine strength and cardio training into one, efficient, full-body, calorie-burning workout.  All workouts conclude with flexibility training as no workout is complete without it.  Click on the exercises to link to step-by-step written and video instructions provided by ACE Fitness.

Previous Fit&Happier Workouts of the Month – January: Body Weight Strength Training; February: Resistance Band Strength Training; March: Free Weight Strength Training; April: Medicine Ball Strength Training; May: Strength Training with Stability Ball; June: Strength & Balance Training; July: Functional Training; August: Interval Training; September: Playground Combo Workout; October: Outdoor Cardio-Strength Combo; November: Timed Circuits

Click on the link to view previous Activity-Specific Workouts of the Month: Hockey & Cross-Country Skiing; Snowboarding & Figure Skating; Golf & Softball; Distance Running; Racquet Sports; Swimming; Waterskiing & Surfing; Cycling, Rowing & Desk Jockeys; Track, Field & Court Sports; Throwing & Pitching; Dancing; Downhill Skiing