I received my first blog comment last night! 🙂 I was very excited, but also intrigued by what I read; the idea that a few short cycles of running and resting could not only be as productive as, but, may be better for fitness than lengthy running sessions 4 or 5 times a week. Now I have vague recollections of reading something about exercise regimes that work on a principle of short sharp bursts of activity interspersed with rest periods, but it was in the context of a celebrity diet article, which instantly screamed fad and put me right off. However, these comments, and the fact that they had originated from a personal trainer, inspired me to do some research.
HIIT = High Intensity Interval Training
An exercise/training principle based on short periods of very intense exertion separated by rest intervals. There is quite a lot of information out there about HIIT, including a Wikipedia page and a number of articles published in scientific journals (Little et al (2010) Journal of Physiology). The idea seems quite simple, 30-60 seconds of maximum effort aerobic exercise followed by 30-75 seconds of rest in cycles repeated 8 to 12 time (starting at a lower number of cycles and building up over time). It is advocated on grounds of taking less time than other intense or endurance type programs whilst achieving the same or better results in terms of fitness, muscle growth and fat loss, apparently making it appealing to everyone who complains their life is too busy for exercise. From what I gather of the science behind it, the high intensity periods are inteed to completely exhaust stored energy in cells so that afterwards your body has to mobilise fat stores to replenish the energy in cells. I assume the rest periods are neccessary to make the intense periods bearable, as 10 straight minutes of maximum exertion is never going to be an appealing workout.
Now this all sounds pretty interesting, amazing results from minimal effort. I am still intrigued but also retain some scepticism. Firstly, the idea of maximum exertion, I’m not sure how easily this can actually be replicated in an everyday workout sort of scenario. Under experimentation, volunteers used exercise bikes in a lab under observation. Now I don’t have access to an exercise bike, so would be working with running/sprinting on the spot, so not sure if this is a comparable activity in terms of effort and energy expeniture. Also, I can’t help but think that being observes and knowing that you are supposed to be putting in maximum effort would affect performance and that trying to do the workout on your own may not be a sufficient replication of circumstances and potentially not be as effective in achieving the optimal outcome achieved under experimental conditions. On another note, having given the technique a trial this afternoon, HIIT isn’t as easy as some would have you believe. I was working on a 60 seconds of running with 60 seconds of rest (it should be noted that in the experiment ‘rest’ actually refers to low intensity cycling rather than doing nothing). Now, 60 seconds of running as hard as you can is actually pretty hard going, even with the rest periods. Having said that, I started on 6 cycles (with the intention of building the routine up as I improve), totalling 12 minutes of exercise, which isn’t exactly a massive time investment and certainly made the whole thing seem better than 30-40 minutes of jogging and squatting. At the end I still felt like I’d had a good work out, being suitable hot, sweaty and tired, certainly got my heart going.
So I think I’m going to give this a go. Again, the experiment worked on a schedule of 3 sessions a week (Monday, Wednesday, Friday), and I think I might try getting in at least 4 a week, as well as keeping up the general toning exercise I’ve been doing (mostly inner thighs and bum). Having never achieved amazing results from exercise I’m not overly optimistic of what changes I can expect to see, but I’ll keep you posted. Hopefully I won’t have cause to resort to chocolate binging that always undoes any effort I put into working out.