HIIT High Intensity Interval Training.

It’s been three years since I started doing regular HIIT workouts, they are still a shock to the system and they don’t get any easier. 

Before this my workouts consisted of running and cycling and other mostly aerobic exercise. My fitness wasn’t bad at all, I could run a sub 3.30 marathon and a half marathon in little over 90 minutes. But I felt that I was getting stuck in a rut, looking back at photographs of myself back then I was actually not that lean, and with all of the long distance stuff (and being in my 40s) I was also losing muscle bulk.

I still ‘go long’ and do a long run every few weeks, but never as many miles as I use to, instead I do short intense periods of exertion and short periods of recovery, this pattern of exercise is called a HIIT workout. 

HIIT is short for High Intensity Interval Training.

HIIT workouts typically involve period of warm up followed by High Intensity exercise possibly to failure then a short period of recovery of about 30 seconds. 

The High Intensity exercise typically lasts a few minutes before the recovery phase, the whole process is then repeated typically involving sets of different exercises that give a total body workout, a typical HIIT workout can last about 20-30 minutes give or take the warm up.

The high exertion of a HIIT workout builds up an oxygen debt that is replayed long after the workout is over, this what is known as ‘after burn’ or to be more scientific EPOC (Excess Post-Exercise Oxygen Consumption). 

The EPOC after a hit workout is significantly more than steady state exercise, and in effect causes an increase in your metabolism for up to 24-48 hrs which is a great way to burn calories.

Due to the Intensity of training in a HIIT workout there is a natural increase in the release of GH and IGF1, and both aerobic capacity and anaerobic endurance are increased. (Med Sci Sports Exerc. 1996 Oct;28(10):1327-30)

In short a HIIT workout helps you burns calories including fat, increases your lean body mass (muscle), improves your muscular strength as well as helping you build endurance.

Popular HIIT exercise regimes use body weight exercises, only need a little space and can be done almost anywhere, little if any equipment or machines are generally needed and the whole workout can be done in little over 30 mins.

There’s nothing new to HIIT, elite athletes have been doing them for years, Peter Coe, (Seb’s Dad) used to put his son through grueling 200m sprints then 30s recovery drills, Coe’s world record in 1981 for the 800 meters of 1:41.73 remained unbeaten until 1997.

Intensive interval training increase your available muscle glycogen and increases strength as well as fitness compared to just a long training run, the intensity of the workout makes your heart rate shoot up then return back to normal repeatedly, each repetition building on the last. 

HIIT workouts should be periods of intense activity where the participant concentrated on form posture until failure catches up, therefore they are fundamentally different to trundling on a treadmill.

After 3 years of high intensity training I can still run a half in 1.30, I’m leaner, stronger and fitter than I used to be and I can fit my workout into my schedule early in the morning helping me reap the benefits throughout the day.

I would have to say that HIIT workout are not easy, at times they can take you to the limit, if you have any medical problems you could be going into dangerous territory so it’s worth getting some advice before throwing yourself into this type of exercise.