23 Aug What’s Wrong with HIIT?
‘Get fit and lose weight with just 16 minutes a week’ sounds like a tagline from one of those late night info-mercials. The difference being this particular methodology has been backed by real science and can be done anywhere. It is known as High Intensity Interval Training (HIIT). It’s the best way to get bang for your buck training. Given that ‘lack of time’ is one of the most common reasons for not participating in exercise this might be the solution for you. But what is HIIT?
High Intensity Interval Training is the training principle whereby you exercise at a maximal intensity for a short period of time, generally less than 2 minutes. You then rest for a similar amount of time before going again at your maximal intensity.
The Tabata Method
This protocol first rose to fame back in 1996 due to a Japanese doctor, Dr Izumi Tabata. He conducted an experiment where he looked at the fitness of elite speed skaters and split them into three groups:
- Group A: one hour of moderate intensity exercise 5 days a week (like most people do when they go to the gym or run outside, steady state)
- Group B: an interval of 30 seconds maximal work to 2 minutes rest with 4 repeats 4 days a week (HIIT)
- Group C: an interval of 20 second maximal work with a 10 seconds rest with 8 repeats 4 days a week (HIIT)
The most significant finding of this research was that Group C had a 28% increase in fitness compared to Group A. So for a total of 16 minutes of HIIT a week you get 28% better results than if you do 300 minutes a week of moderate exercise.
However this study focused primarily on HIIT and its effectiveness on fitness, not fatness.
The 8/12 Method
So in 2008 the University of New South Wales decided to take this a step further and look at whether HIIT was beneficial to fat loss in young women? The experiment split the girls into three main groups:
- Group A: No intervention
- Group B: 40 minutes of moderate intensity exercise 3 days a week (steady state)
- Group C: an interval of 8 second maximal work with 12 seconds rest, for 20 minutes, 3 days a week (HIIT)
Interestingly they found that there were improvements in fitness in both Group B and C. However only the HIIT group had significant decreases in total body mass and body fat.
But is it too good to be true?
A study published just last month from the University of Sydney, has the entire fitness world scratching their heads. The research suggested that HIIT might not be as effective as we first thought. They split the participants into 3 exercise groups
- Group A: walking 33 minutes, 3 days a week (low intensity steady state)
- Group B: interval of 4 minutes moderate intensity, 3 minutes walk, 4 repeats, 3 days a week (moderate interval)
- Group C: interval of 30 second maximal intensity, 4 minutes walk, 3 repeats, 3 days a week (HIIT)
What they discovered is that there was no significant difference between Group A and Group C in terms of fat loss. So is our revolutionary way to exercise flawed? Not quiet. As they do go on to say that HIIT is a much more time efficient solution for similar results and that more research is needed.
There are also a couple of key differences between the methods, which require further research. In the 8/12 method, there is a total of 8 minutes maximal intensity to 12 minute rest. The Sydney University study had a total of 90 seconds maximal intensity to 12 minutes rest. Perhaps the rest period is too long and there is not enough high intensity?
The biggest thing to be taken out of this particular research is the fact that walking or low intensity exercise for 30 minutes a day is a fantastic way to manage your body fat.
It is important to bear in mind HIIT was originally created for elite athletes, so if you have a pre-existing heart condition please seek doctors clearance. If starting out it is recommended you attempt 4-6 rounds of intervals and build intensity from there. Doing your HIIT training on a stationary bike is also a good starting point and you can develop your HIIT across other exercise forms, as you get fitter.
- Walk everyday for 30 minutes
- 2-3 HIIT sessions of 8 second sprint to 12 second rest for 20 minutes
- HIIT sessions of 20 second maximal intensity, 10 second rest for 8 sets
- If you are looking at training for a running event, one long run every week is advisable