April 24, 2024

High intensity interval training, also known as HIIT, has become immensely popular in the last decade. HIIT involves alternating brief bursts of very high intensity exercise (work intervals) with brief segments of lower intensity exercise (recovery intervals). One problem with some types of HIIT is that they call for such high intensity bursts – literally all out sprints – that they’re not practical for everyone, and possibly not even safe for older or over individuals.

A recent study out of McMaster University has tested a protocol for HIIT that produces impressive results in a short period of time without the need for “all-out” sprints…

Many of the previous studies on high intensity interval training used ALL-OUT intervals on a specialized cycle ergometer, pedaling against a high resistance.

Results of High Intensity Interval Training Study

High Intensity Interval Training
High Intensity Interval Training

This type of training takes a high level of commitment and motivation and can result in feelings of severe discomfort and even nausea.

One of my colleagues mentioned in our Burn the Fat Forums that he remembers exercise physiology class in college where they did all out cycle ergometer interval sprint testing and nearly everyone either puked or passed out.

The Tabata protocol for example, is a brief but brutal 4 minute HIIT workout often spoken of by trainers and trainees alike with both appreciation and dread. It’s no walk in the park.

The truth is, some high intensity interval training protocols which have been tested in the lab to produce big improvements in cardiovascular function and conditioning in a short period of time, may not be practical or safe, especially for beginners, obese or older adults.

In this new study out of McMaster University, a HIIT protocol that was more practical and attainable for the general population was tested to see how the results would compare to the more “brutal” very short, but extremely intense types of HIIT.

Here’s what the new HIIT protocol looked like:

  • Study duration: 2 weeks
  • Frequency: 3 sessions per week (mon, wed, fri)
  • Work intervals: 60 seconds @ constant load
  • Intensity Work intervals: “high intensity cycling at a workload that corresponded to the peak power achieved at the end of the ramp VO2peak test (355 +/- 10W)”
  • Recovery intervals: 75 seconds
  • Intensity Recovery Intervals: Low intensity cycling at 30W”
  • Rounds: 8-12 intervals
  • Progression: 8 intervals 1st two workouts, 10 intervals second two workouts, 12 intervals last 2 workouts.
  • Warm up: 3 min:
  • Duration of work intervals: 8-12 minutes
  • Total time spent: 21-29 minutes.

Results: In just 2 weeks, there were significant improvements in functional exercise performance and skeletal muscle adaptations (mitochondrial biogenesis). Subjects did not report any dizziness, nausea, light headedness that is often reported with all-out intervals.

They concluded that HIIT does not have to be all-out to produce significant fitness improvements and yet the total weekly time investment could remain under 1 hour.

On a personal note, I REALLY like this kind of interval training: 60 second work intervals repeated 8-12 times. Here’s why:

Body composition was not measured in this study, but I believe that enough energy expenditure can be achieved with 20-30 minutes of this style of interval training to make significant body comp improvements in addition to all the cardiovascular conditioning improvements.

That’s another problem with super-brief and super intense high intensity interval training programs: The cardio and heart benefits are amazing, but you can only burn so many calories per minute, no matter how intensely you work. To call a 4-minute workout a “good fat burner” in the absolute sense is ridiculous.

Somewhere in between long duration slow/moderate steady state cardio and super short super-intense HIIT lies a sweet spot for fat-burning benefits… a place where intensity X duration yield an optimal total calorie expenditure at a reasonable time investment. Perhaps this 20-30 minute HIIT workout is it?

If you’ve read any of my other articles on cardio, you’ll know that I’m not against steady state cardio, walking or even light recreational exercise and miscellaneous activity as part of a fat loss program. All activity counts towards your total daily energy expenditure, and in fact, the little things often add up during the day more than you would imagine (just look up N.E.A.T. and see what you find).

But for your formal “cardio training” sessions, if you’re going to use traditional cardio modes (stationary cycle, etc.) and if your goal includes fat burning, and if your time is limited, then this type of high intensity interval training is a great choice and you can now say it is research proven…

Not to mention… the excuse, “I don’t have enough time” has been officially busted!

Train hard and expect success!

Tom Venuto, author of
Burn The Fat Feed The Muscle

9 thoughts on “High Intensity Interval Training Research

  1. I agree that for most people that they already have to have moderately good cardiovascular fitness before starting a HIIT program. It would be nice if there were a progressive program of HIIT workout with a gradually increasing times of high intensity and gradually decreasing rest times perhaps based upon heart rate response or recovery for those who were less fit.

  2. I agree with Aaron. While high intensity training is essential for burning excess fat and developing lean muscle mass, it’s still important to establish a strong foundation. Nice article!

  3. I agree with you Aaron but in addition to the cardio, training is also recommended to increase stamina and strength. The HIIT workouts look great but as mentioned many of the obese and unfit would probably get discouraged as this is not something to jump into and expect immediate results without already conditioning the body with exercise. I have watched my daughter and friends who are in team gymnastics go through one of these workouts and seen them dragging before the end of the session.

  4. Excellent post to help beginners understand how they can safely and effectively incorporate HIIT into their workouts. The biggest problem for people new to working out is trying to do too much and then getting discouraged and quitting. HIIT is so effective that it’d be a shame to see someone give up on them because they didn’t follow the advice in this post.

  5. It sure looks like the L.S.D. (long slow distance) days are over. HIIT has been proven to be much more effective, and efficient. I’ve been doing HIIT for 2 years now; and it has made a huge difference in my results!

  6. I have just started working at Epic Gym, which is a K1 kickboxing gym with a difference. In the short time I have been here I have seen that K1 is an excellent system for dramatically improving -loss, core strength, muscle tone, cardiovascular fitness, flexibility, speed & agility, hand-eye coordination, mental alertness, balance, posture and self confidence…not to mention a great stress buster. It has had a lot of great press including being part of GMTV’s Beach Body Diet Plan – http://www.epicgymkickboxingclublondon.co.uk/video.html. The instructor is fab and will only work people to their personal boundaries. Therfore the classes are full of all shapes, sizes and levels. If you want to try something difference and really fun to burn some serious calories, come and try the first class for free.


  7. I watched a lot of folks give up on their workout simply because the uninformed trainer is making them workout beyond their energy capacity level.

    Very nice post 😉

  8. Excellent post. I’ve said many times, most people are not as fit as personal trainers, and for us to push HIIT workouts to the obese, unfit and sedentary as the best method of fat loss can be almost unethical when you consider most of these people are not healthy and fit enough to perform at that level of intensity. I still feel most beginners need to do a good amount of steady state cardiovascular training to get their heart, lungs and mind conditioned to be able to perform at a higher level. Progression is the key!

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