If you pay the slightest bit of attention to fitness trends, you've probably heard HIIT (high intensity interval training) is the greatest thing to happen to workouts since rubber soles shoes.
The thing is, the term "HIIT" has been thrown about so much in recent years, it's true essence has become diluted. I was chatting with Fabio Comana, M.A., M.S., faculty instructor at San Diego State University, and University of California, San Diego at the IDEA World Fitness Conference where he was giving a lecture about this topic. He says, many of us out there think we're doing HIIT programs but we're really doing "some intensity" or "slightly higher intensity" intervals instead. This means we may not actually be getting all those amazing HIIT benefits we read about like increased V02 max and endurance, improved insulin sensitivity, reduced body fat and blood pressure and increased EPOC, excess post-exercise oxygen consumption (a.k.a. "afterburn"). Not to mention the well-touted benefit of saving time since HIIT workouts are supposed to be short and intense.
HIIT programs were originally developed to make athletes bigger, faster and stronger. They were intended to be all-out maximum efforts to where you need substantial recovery time after each one. If you're doing an interval workout that lasts for around an hour, it's probably not a true HIIT workout. You simply can't perform enough intervals at your maximal performance levels to fill an hour unless you're taking very long recoveries. Your body runs out of the energy necessary to perform at that level and it needs sufficient recovery time to replenish before you can do it again, like a day or two.
What most of us are really doing, says Comana, are "HVIT" (High Volume Interval Training) or "VIIT" (Variable Intensity Interval Training) workouts. "High volume" meaning a lot of intervals or reps, not performed at maximal levels or, "variable intervals" meaning not all the intervals are done at same intensity or duration, nor are the recoveries. Is this a bad thing? Hell no! I've been doing this type of training for years and I've seen results in myself and my students. I'm not trying to win a medal in a sport. The only thing I compete at nowadays is trying to look good as I get older, which is a highly competitive sport in L.A.!
Unless you have unlimited hours in the day to train, making the most of your workout time is probably important to you. Time efficiency happens to be one of the key features of serious HIIT programs and why they are so alluring. When done properly with a coach or trainer, hands down, HIITs get the most bang for the buck. A 2012 study compared 6-weeks of Wingate-based HIITs against traditional endurance training that met current public health guidelines.
The results showed similar improvements to the muscular and cardiovascular systems but the HIITs required up to 90 percent less training volume and up to 67 percent less time commitment. Now there's a nice value proposition!
This is just one of a myriad studies published on the topic. While the benefits of HIIT programs have been studied and discussed practically ad nauseam, HVIT and VIIT programs have not so, we don't definitively know how these less intense, higher repetition workouts affect markers like cardiometabolic diseases, weight loss, endurance, aerobic and anaerobic fitness, etc. All we really have for the these types of programs are impressive looking before and after pictures and testimonials which is apparently proof enough for most people to sign up for a class or buy a DVD.
Should you ditch your current methods of interval training for the real deal HIITs? Unless you're a competitive athlete looking for an edge, probably not, especially if you're making progress. HIITs can also increase your chances of injury especially if you're not following a proven protocol and respecting your body's needs for recovery. Comana says VIIT programs are the best bet for most because they can combine some higher intensity intervals with active recovery, balance and stabilization and, lower intensity intervals.
By doing HVITs and VIITs you can sustain longer workouts, have calories-burned bragging rights, plus reduce your risk of injury while having a more enjoyable experience. Did I just say "enjoyable?" While the words "enjoyable" and "workout" are rarely used in the same sentence, new research shows that people subjected to certain HIIT programs enjoy them about as much as digging out ingrown toenails.
The study divided relatively sedentary young-adults into three groups using stationary bicycles for exercise. The first group performed 20-minutes of steady-state, moderate-to-vigorous intensity exercise. The second performed four minutes of Tabata training (20-seconds of highly intense effort followed by 10-seconds of unloaded, recovery pedaling). The third group performed 20-minutes of interval training consisting of sets of 30-seconds of intense exercise followed by 60-seconds of recovery pedaling.
The research found all groups improved significantly, but interestingly, no one group improved significantly more than the others. This implies that in relatively untrained young adults, there is no apparent advantage in doing more intense exercise.
There was one thing that did significantly change over the 8-week study: their enjoyment level. The participants reported liking their program less and less each week with the Tabata group hating life the most.
What are the key takeaways?
- That unless you're a competitive athlete, HIITs in their true form are probably not necessary.
- A sound, high volume or variable intensity interval program is a better fit for most. A knowledgeable trainer or instructor can make all the difference here.
- Newbies will hate life and likely drop out if they start off with Tabata or other type of HIIT training!