High intensity interval training is all the buzz in the health and fitness world. Check out what it’s really all about, how it works and why it’s here to stay in smart personal training and strength and conditioning programs.

What exactly is high intensity interval training?

High-intensity interval training (HIIT) is a cardiovascular training technique that alternates between speed and recovery intervals to increase the overall intensity of your workout. HIIT is used by athletes and everyday exercise enthusiasts to reach performance goals and enhance fitness and well-being. HIIT is the number two fitness trend in the world following behind body weight training at number one, according to the 2015 American College of Sports Medicine National Survey. Interval training has been around for years. However, only in the recently have fitness enthusiasts been awakened to the value of such training. HIIT is growing in usage across all modes of exercise, as it can be beneficial for anyone.

How does HIIT work?

A research article sponsored by the Strength Coach, “Interval Training- HIIT or Miss,” states that most endurance workouts, such as walking, running, or cycling—are performed at a moderate intensity, or an exertion level of 5-6 on a scale of 0-10 (0 being little to no effort and 10 being maximal effort). High intensity intervals are done at an exertion level of 7 or higher, and are typically sustained for 30 seconds to 3 minutes (although they can be as short as 10 seconds or as long as 5 minutes). The higher the intensity, the shorter the speed interval (Strength Coach). Recovery intervals are equal to or longer than the speed intervals. High intensity interval training is done at a level of 80-95% of maximal aerobic capacity.

According to a T-Nation article on HIIT training, the most popular forms of HIIT training is the Tabata. A Tabata interval is a high intensity interval training protocol that was originally created by Japanese researcher Dr. Izumi Tabata. Every Tabata interval totals four minutes that consists of eight rounds of 20 seconds of high intensity exercise followed by 10 seconds of rest usually performed on one type of exercise such as sprinting.

What are the benefits of high intensity interval training?

HIIT is an approach to training that provides several health, fitness and performance benefits in a time-efficient manner. Many physiological benefits are accomplished through HIIT that have been backed up by clinical research at the University of New Mexico. In a study published in the Journal of Physiology, people who participated in HIIT for eight weeks doubled the length of time they could ride a bicycle while keeping the same pace. Participants in the study performed HIIT bicycling workouts approximately every other day. HIIT quickly adapts the cellular structure of your muscles, enabling one to increase their endurance regardless of what exercise activity they choose.

The alternating exercise also helps your body maximize the volume of air you breathe in during a workout. According to the American College of Sports Medicine, more oxygen is consumed during an HIIT workout than in non-interval exercise. This extra oxygen increases your rate of metabolism for a couple of hours after one session of HIIT exercise. Higher metabolism causes your body to burn fat and calories quickly.

HIIT does not only beat standard cardio as the most effective and efficient form of exercise, it also provides health benefits you simply cannot get from regular aerobics, such as a tremendous boost in human growth hormone (HGH), aka the “fitness hormone.” One study published in the Journal of Obesity reported that 12 weeks of HIIT not only can result in significant reductions in total abdominal, trunk, and visceral fat, but also can give you significant increases in fat-free mass and aerobic power.

Another study published by PubMed found that unfit but fairly healthy middle-aged adults were able to improve their insulin sensitivity and blood sugar regulation after just two weeks of interval training. A follow-up study also found that interval training positively impacted insulin sensitivity. In fact, the study involved people with full-blown type 2 diabetes, and just one interval training session was able to improve blood sugar regulation for the next 24 hours.

How are HIIT workouts designed?

Interval training can be performed on any type of equipment or any mode of exercise including cycling, swimming, running, sprinting, body weight exercises, and weight training. For a HIIT workout a few variables should be considered. The duration, intensity, frequency and recovery are those variables. The links between work and recovery intervals are important to consider.

HIIT protocols vary widely. There’s no one best single way to structure them. Experiment with shorter and longer work and recovery intervals to find what is best for you. Keep in mind that the most common mistake made with interval training is making the recovery intervals too short. You do not need to eliminate all of your aerobic exercise for HIIT training. A good balance, for example, might be two sessions of HIIT per week, along with 1-2 sessions of steady-state cardio exercises. Moderation is the key to long-term success, so challenge yourself—but don’t drive yourself into the ground. Get ready to see major changes in your body and your fitness level!

Six tips To get the most out of your Tabata workout

  1. Warm up for at least 10 minutes. That’s part of the original protocol.
  2. Use full-body exercises that engage as many muscle groups as possible.
  3. Exercises using bodyweight, a weighted vest, or free weights are all acceptable.
  4. Go full out during the 20-second bursts. Seriously, don’t slow down.
  5. Try hard to find your breath during the 10-second rests. Good luck.
  6. Be prepared to sweat.

– Written by Hyatt Training intern Jayce Brownson



American College of Sports Medicine. (n.d.). High-Intensity Interval Training. Retrieved from https://www.acsm.org/docs/brochures/high-intensity-interval-training.pdf

Boyler, M. (2015). Interval Training- HIIT or Miss? Retrieved April 29, 2016, from http://www.strengthcoach.com/public/1766.cfm

G. R. (n.d.). The New York Times. Retrieved April 29, 2016, from http://mobile.nytimes.com/blogs/well/2016/03/18/ask-well-20-seconds-to-better-fitness/?smid=fb-nytimes

Tumminello, N. (n.d.). Six New Tabata Workouts for Fast Fat Loss. Retrieved April 29, 2016, from https://www.t-nation.com/training/6-new-tabata-workouts-for-fast-fat-loss