What I love about blogging is how it forces you to peel back the layers of a topic to really find out to really get to the core of the issue. I started off with a rough idea for an article on HIT training but as I write a little, read a bit more, think it through and repeat the posts seem to subdivide and multiply! This post is my second article in a series on HIT (High Intensity Training), but in writing it I feel like the different ‘myths’ of HIT training almost warrant their own separate articles so I hope you find it as interesting as I have. If you missed the first article, catch up here: HIT Training – what is is and how does it work?. As always, if there’s an aspect you think needs clarifying or elaborating on, leave me a comment as I’d love to hear your thoughts.
The idea of losing fat, increasing aerobic and anaerobic fitness, reducing blood triglycerides and LDL cholesterol and getting faster and stronger in your sport from 4 minutes of training has proved irresistible to everyone from sports coaches to journalists, fitness entrepreneurs and people looking to lose a bit of weight. There is a vast amount of content available online suggesting how to use the principles of HIT training some of which, once you’ve understood the precise conditions of the protocol, are mildly amusing. My personal favourites are videos labelled as total-body HIIT workouts with a series of resistance exercises performed in 20 second bursts by instructors who are almost deadpan and definitely not breaking a sweat.
Here are 5 common misconceptions about HIT training to be aware of before you invest time and effort into a new training programme:
- Tabata training is the ‘gold standard’ of high-intensity training
Not necessarily – the ‘best’ form of training is what is best for you. Tabata training is the name given to the protocol tested in the study conducted by Izumi Tabata and his colleagues at Ritsumeikan University in Japan in 1996. It was the first study into this type of high-intensity, low-volume training and made some remarkable findings, although some coaches were already using the principle with success in the field (Seb Coe talks about his high-intensity training in the 1970’s in his book “Running My Life”).
Tabata’s research is well-known as it produced impressive results and was the first in its field. The test protocol of 6-7 x 20s at 170% VO2 Max with 10s rest found that this combination taxed both the aerobic and anaerobic energy systems almost maximally, compared to harder intervals with longer recovery between efforts which was much easier on the aerobic system1. In the years since Tabata’s research was first published, however, numerous other studies have been conducted with interval length ranging from 10-60 seconds and recovery duration also varying widely. In sports performance, training benefits are not limited to physiological markers so the the best approach for you depends on your body and your goals.
- HIT principles can be applied to any kind of training
The principles of HIT training are about cardiovascular fitness and working with a high heart-rate in the zone between lactate threshold and maximum heart rate. Repeated short bouts of resistance training followed by shorter rest periods will likely not challenge the cardiovascular system and will rather challenge muscular endurance. Be specific about what you want to achieve before deciding on what training approaches you will follow.
- HIT has no use for endurance athletes
HIT can be very beneficial to all kinds of athletes as well as the general population, but as with anything there are some caveats. While it’s true that however effective HIT might be at improving markers of aerobic endurance, it’s very unlikely that you would be successful in completing a marathon on 30 minute workouts. Looking at scientific studies alone could lead to overlooking the psychological benefits of conventional training approaches and for endurance.
The athlete’s confidence in their own stamina and ability to sustain effort for prolonged periods, as well as being used to occupying their mind over one or more hours’ of continuous work is vitally important, not to mention getting used to pacing, fuelling, hydration and all the other factors that contribute to endurance disciplines. Additionally, since the approach has health benefits for the general population as well as performance benefits for trained athletes, different studies into HIT training use different subjects; men, women, trained and untrained athletes. It’s worth paying attention to this before translating the results of a given study to your own training.
Having said all this, the number of studies2 showing significant improvements in endurance athletes shows that adding HIT training to your programme is likely to boost your performance. One of the most effective ways to improve is to give your body a new challenge, mix things up or ‘shock’ the system so adding some HIT training to your regime is a great way to do this. Working out how many sessions, for how many weeks and so forth will depend on what you’ve done in the past, where you’re at now and where you want to get to, as well as factors like time available and motivation to familiarise yourself with what 170% VO2 max feels like!
- You will burn more calories doing HIT training than long-steady endurance workouts
There a few factors at play in this question. First let’s look at energy consumed during the training session itself. If you completed 1 round of 4 minutes high-intensity training according to the Tabata protocol, even with a decent warm up of 15-20 minutes plus 10 minute cooldown, you will only be working for maybe 30-35 minutes and much of this is at lower intensities as you build up towards and down from the HIT set, so there is a limited amount of calories you can burn during the session. For the average build, this might be about 400 kcals. Compare this to a 90 minute long steady run: the energy expenditure is likely to be more in the 800-1000 kcals range. Unfortunately, the amount of energy used is not proportional to the perceived effort, that is to say, working twice as hard doesn’t mean you can workout for half the time.
It’s true that the effect of working close to maximum effort puts a big strain on the body which takes hours to properly recover from and during this recovery period, your metabolism is elevated. The is effect is known as “Elevated Post-exercise Oxygen Consumption” or EPOC, and there are claims that it can boost energy consumption by 13% in in the first 3 hours post-workout and 4% in the 13 hours after that3, but studies into this effect have had mixed results and even if you work out the extra calories burned based on the 13% and 4% figures, it doesn’t add up to that much; for a 35 year-old, lightly-active man who weighs 84kg this is only just over 100kcals, equivalent to about 10 minutes of running. Thus the benefits of HIT training are the physiological ones that happen as a direct response to training and increased calorie burn is of much less significance.
- HIT training breaks down lean muscle tissue
It is unlikely that your body will begin to break down protein as an energy source in high-intensity training because sessions are well under an hour in length and provided you are consuming adequate energy from your diet, you have sufficient glycogen stores in your muscles to provide all the energy needed to get through the session. HIT training is a great option for people focussed on building lean tissue because they will improve their aerobic fitness which is needed to recover after a hard set of lifts. Having a lot of muscle mass requires a lot of oxygen to recover after a set and it’s essential that the cardiorespiratory system can deliver sufficient oxygen to those hungry muscles in the minutes following a resistance set so the aerobic performance benefits of HIT training are applicable to strength and endurance athletes.
HIT training is not for the faint-hearted and to get the benefits found by researchers, the intensity of intervals needs to be well over the your VO2 Max, meaning you go straight into oxygen debt and all the delightful symptoms that go with it – burning sensations in the muscles, severe breathlessness and in some cases, nausea and a taste of metal in the mouth. It can take some time to get used to this level of intensity and should be worked towards gradually if you haven’t done interval training before. The good news is that the principles of bringing about anaerobic and aerobic overload with insufficient recovery periods between intervals can be adapted to fit the individual’s aerobic and anaerobic fitness levels.
Have you tried HIT training or are you thinking about giving it a go? Feel free to add your thoughts in the comments below.
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- Tabata I, Irisawa K, Kouzaki M, Nishimura K, Ogita F, Miyachi M. Metabolic profile of high intensity intermittent exercises. Med. Sci. Sport Exerc. 1997;29:390–395. http://www.ncbi.nlm.nih.gov/pubmed/9139179 Accessed 17/11/2015.
- Recent studies into different applications of HIT training include:
- Gibala, Martin J et al. “Short-Term Sprint Interval versus Traditional Endurance Training: Similar Initial Adaptations in Human Skeletal Muscle and Exercise Performance.” The Journal of Physiology 575.Pt 3 (2006): 901–911. PMC. Web. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1995688/ 25 Nov. 2015.
- Rozenek R, Funato K, Kubo J, Hoshikawa M, Matsuo A (2007) Physiological responses to interval training sessions at velocities associated with Vo2max. J Strength Cond Res 21: 188–192 PMC. Web. http://www.ncbi.nlm.nih.gov/pubmed/17313282 25 Nov. 2015.
- Helgerud J, Høydal K, Wang E, Karlsen T, Berg P, Bjerkaas M, Simonsen T, Helgesen C, Hjorth N, Bach R, Hoff J., “Aerobic high-intensity intervals improve VO2max more than moderate training.” Medicine and Science in Sports and Exercise, 2007 Apr;39(4):665-71, PMC, Web. http://www.ncbi.nlm.nih.gov/pubmed/17414804, 25 Nov. 2015
- Osterberg, K. L. & Melby, C. L., 2000. Effect of acute resistance exercise on postexercise oxygen consumption and resting metabolic rate in young women.