Posted on November 12, 2014 by Jenny Cromack
HIIT is in my opinion an often overused phrase in the fitness community, HIIT this HIIT that but what is HIIT?
HIIT stands for High Intensity Interval training, its actually a very broad term used to describe an intermittent session combining periods of anaerobic work with periods of low intensity effort. This combination can be manipulated in more ways than I could list in one life time, but the crux of this training is that you work close to 100% effort for a period of time then rest for an undisclosed period of time until you can repeat the anaerobic phase.
Looks easy on paper, but when done properly it will leave you breathless gasping for air, praying that you don’t cough up a lung!
Why is HIIT so effective?
If you’re a bit of a geek like me you’ll like understanding why this approach is so effective. HIIT uses anaerobic pathways, this means essentially that the body makes energy in the absence of oxygen… this occurs mainly using the:
- Phosphagen system
- Glycooloysis
So, if you’re still with me, imagine this scenario. You’re late for the train to an important meeting, you head outside and see the train you need to be on is pulling up to your bus stop…..oh dear time to sprint otherwise you’re going to be late! You start sprinting, during the first 10 seconds you use energy from the phosphocreatine system, after ten seconds have passed you run out of phosphocreatine, your body goes ‘aaargh!’ and starts a process called glycolysis. The ins and outs of this isn’t that important, however you get some more instant energy… but as a by product of this process you start producing lactic acid….. aka a burning hell!
The stress of glycolysis is what causes all the magic to happen.
With HIIT your spending periods of time going into glycolysis, unfortunately this cannot be continued for long periods of time, so you recover, catch your breath, utilise some of the lactic acid then repeat the process.
The Physiological Benefits of this are as follow:
- Increased metabolic enzymes
- Improved resting muscle glycogen
- Elicits a greater post exercise oxygen response
- Elevates numerous hormones including growth hormone
- Elevated metabolism for up to 3 hours post exercise
- Ultimately this all leads to a great fat burning effect and improvements in fitness. So if you want to lose weight then head for a HIIT session.
However you don’t get all this for nothing, poor effort leaves poor results. Each interval must be almost maximal effort, if you don’t put the effort in you won’t reap the rewards…. Good luck entering the HIIT hell…..but remember it will be worth it!