I was chatting away on the phone to my darling mother the other day about this, that and the other when our conversation took its usual progression onto health / medical related topics. Mum always has some insightful new information about the latest study or trend in the medical world to share with me and it’s often something obscure like how mushrooms can actually provide humans with their daily vitamin D requirements. This particular calls topic was high intensity interval training and for the first time I think I was actually more knowledgeable on the topic that mum was.
High intensity interval training (HIIT) is a form of exercise that is growing in popularity in the fitness industry. No one has time to be slogging it out at the gym for 2 hours every day, which I guess is a good thing because research now shows that just 20- 30 minutes of high intensity exercise is actually better for you, both for fat loss and cardiovascular gains!
What does this form of training involve? If you think about it it’s kind of self explanatory… Short bouts of HIGH (not medium) intensity work where you literally bust your guts and push yourself to your limits, followed by a short period of rest and away you go again. The work to rest ratio is the key component of the training and it will be determined by what you are setting out to achieve
- If your goal is to increase speed then you would do a session favoured towards the rest component. For example if you work hard for 30 seconds you may give yourself 90-120 seconds recovery which would be a 1:4 ratio.
- If you are looking more at training your body to work at higher intensities for longer periods you may do a 2:1 or 1:1 ration (meaning you would work hard for 30 seconds and have either 15 or 30 seconds recovery)
The rest is important, if you don’t allow adequate recovery the intensity of your ‘work’ intervals will suffer and you won’t get the best benefits from your session.
Why does it work? The most appealing factor of HIIT is the affect it has on the way your body uses fuel not just during your training session but for the 24 hours following. Working at such a high intensity sends your metabolic rate through the roof resulting in efficient conditioning of both your aerobic and anaerobic systems.
Without getting too far into the technical stuff one way to look at what is occurring is that during bouts of high intensity exercise where you are working close to your threshold you are unable to get enough oxygen to working muscles so you accumulate an ‘oxygen debt’. This needs to be ‘repaid’ and your body does this by revving up your metabolism for a period of time post exercise. This is termed excess post-exercise oxygen consumption or EPOC. The greater your EPOC the longer your body will burn fat for following a training session.
But wait there is more… HIIT promotes production of testosterone and human growth hormone (HGH) (ladies don’t freak out this doesn’t mean you will get bulky!!). HGH is important in the fat burning process but also helps to slow down the aging process.
HIIT doesn’t apply only to running.. It can be done on an exercise bike, cross trainer, rowing machine, using weights or even just the set of stairs at your local park; just remember to choose a work:rest interval that is suited to what you want to achieve. Beginners best to start out with longer rest periods to allow your body to adjust to this type of training.
For example I did a little interval session the other day using a nasty little hill down the road from my house. The way I set up the session was on 1 minute 45 second time intervals. I ran as fast as I could to the top (took about 40 seconds), meaning I had just over a minute to get back to the bottom. I generally had about 10-15 seconds to spare at the bottom before I had to go again. I repeated this 15 times which all up took just over 25 minutes. Now this was a particularly tough session but all you have to do is alter the time periods to make it suit you so you get adequate recovery to ensure that your runs up the hill are at maximum effort!
The work / rest style of training is time efficient (busy 9-5’ers you now have no excuse), doesn’t require an expensive gym membership (or any equipment for that matter), challenging (assuming you push yourself hard enough); and its SO much better for your body than those long boring gym sessions you have spent the last year forcing yourself to do.
Get stuck into some interval training; it’s the perfect recipe for a stronger, fitter, leaner body.. and it’s just in time for summer!