It seems a few people have gotten a little scared of High Intensity Interval Training (HIIT) as a result of the experience of poor Andrew Marr, but is there really anything to be worried about by this newfangled way of training, and can HIIT be classed as newfangled anyway?
So for those that don’t know, BBC Presenter Andrew Marr suffered a major stroke in January 2013 and has placed a sizeable chunk of the blame on high intensity training and rowing machines. Given Mr Marr’s status as a high profile individual this has encouraged some to question the HIIT concept; particularly those sections of the media who, perhaps to ease the consciences of themselves and their sedentary readers, delight in telling us that exercise might just be bad for us after all.
The most obvious point here is that it is indeed just one person and therefore not statistically significant, plus it’s impossible to say whether Mr Marr would have had a stroke had he just been for a steady bike ride. However, the fact that did use a rowing machine does make one wonder if his technique played any part at all in his mishap. Next time you’re at the gym take a look at some rowers and watch the way that their cervical spines (necks) gently extend and flex – particularly those whose eyes are fixed on the display.
Now imagine the same thing with a not particularly skilled rower who is out to shatter his sprint times. It is understood that Mr Marr’s stroke concerned an artery very close to the neck. Pure speculation of course, and this doesn’t mean that rowing is bad, just that as with many, many other exercises, any increase in intensity should not be a the expense of good form.
Back to the subject of HIIT training. For years and years, coaches and trainers have known of the value of short burst high intensity workouts with short recoveries. It is only recently that some bright young go-getters have packaged it into a snazzy bite-sized acronym in order to impress the masses, who in turn are perhaps only just starting to realise that ‘Boot Camp’ is indeed just ‘Circuit Training’ but outdoors.
What the coaches of yesteryear (and we’re talking at least a hundred years ago) instinctively knew, and this hardly takes a genius to figure out, is that high intensity performances required high intensity training. Burning of excess fat calories wasn’t really a factor in those pre-fitness industry days. That everyday people could also benefit from high intensity training has also been known for some time. It takes longer to recover from a higher intensity workout, and that means an extra demand on the body in terms of energy (calories).
There has always been a trade-off in exercise between intensity and duration. How hard must a 30-second activity be in order to burn more calories than, say, a three minute activity? Clearly if both are at the same intensity, then as long as it doesn’t put us in a catabolic state the one with the longest duration has to burn the most calories. However, if we increase the intensity of the shorter activity, at what point does it ‘overtake’ the longer activity? With this in mind we look to research and typically, as with most exercise research, it leaves as many questions as answers.
Apart from the usual flaws like a lack of participants, most of the research has only sought to compare the two extremes. For example one Australian study used steady state activities of 40 minutes at a heart rate of only 60% of maximum – now that’s a real plod. This they compared to a HIIT workout with sprints of just 12 seconds. It’s almost as if they have a preconception of the results.
The upshot however, is that most people see HIIT training as something that ought not to take longer than a few minutes, when the truth is that an effective interval session can take many, many minutes and that there is a clear sliding scale between intensity and duration. We still don’t know what the optimum length of an interval session ought to be in order to burn the most calories.
Research aside, the question still remains about whether everyday folk ought to be participating in HIIT. For those who have little or no experience of sport or even exercise, there is a danger that their HIIT sessions will simply turn into shorter versions of their low intensity steady state stuff, and they just get less benefit. Some people really just don’t know how to push themselves to the max, while nothing turns on the masses like the idea that you can get the same benefit for less effort.
The advice for these people is that they should graduate onto an HIIT program via some longer duration (and by definition, lower intensity) interval training, with the emphasis on an increase in performance as the intervals are shortened.
In terms of safety, the timid and the short-cutters are the least of anyone’s worries. It’s the ones who really do know how to push themselves that are at risk. High intensity training over a short duration does make an immediate demand on the heart. The risk is not so much how high the heart rate goes, but how quickly it gets there. An elevated heart rate will help to gently unclog arteries, but a sudden woosh of blood can rip off bigger chunks of fatty deposits and other nasties, that can end up blocking arteries further down the line thereby causing a stroke.
None of this means that HIIT is too dangerous to do. It just means that it ought to be part of a more rounded exercise programme which includes a reasonable amount of steady state activity and, more importantly, a thorough cardiovascular warm-up. Sorry to disappoint those who think they can get in and out in three minutes. A good warm-up will take the exercising heart rate up a lot closer to the level that the HIIT will demand; the more shallow the curve, the safer it is.
Again, even for the gung-ho amongst us, it’s a good idea to graduate our training towards the highest and shortest intensity interval training. To do this, it’s a great idea to record exactly the durations and intensities that we use; whilst always remembering that interval training can be done over various competing intensities and durations.
Of course, we at UsFitties wish Andrew Marr well and hope he makes a full recovery, but it is important to understand HIIT and not blame it where blame should not, or cannot, be placed.