What is HIIT training?

Phil Goulding Phil Goulding Nuffield Health Senior Personal Trainer
Nuffield Health Senior Personal Trainer Phil Goulding explains what HIIT training is, what it's good for and when to use it.

HIIT training stands for High Intensity Interval Training - a form of cardiovascular exercise. HIIT can be further broken down into two main categories SIT (sprint interval training) and HIT (high intensity training). 

Two forms of HIIT

SIT is a form of very intense interval training that should only be performed by already well-conditioned people who have no contrary health conditions. You perform 3–5 intervals of very short maximal-intensity exercise working until you can't sustain the intensity, followed by a prolonged recovery period. This would typically be 20–30 seconds of work followed by a 3–5 minute rest interval. 

HIT is much more appropriate to the general public or average gym-goer. This involves work periods ranging from 30 seconds to three minutes, working between 80–100% of your maximum heart rate with shorter recovery periods than SIT. There is no specific formula to HIT, but as a rule of thumb I'd recommend your recovery period should be at least the same as your work interval, and can become shorter as you get fitter. 

If you're not sure how hard you should be working to reach 80–100% of your maximum heart rate zone, a heart rate monitor can be a very useful tool. To work out an estimate of your maximum heart rate, you simply take your age off 220. So if you're 30, your maxiumum heart rate would be 190. And then to work out 80% of this, you multiply it by 0.80 – which would be 152. So you'd be aiming to get your heart rate somewhere between 152 and 190 if you're a 30 year old.

What is HIIT training good for?

HIIT training is great for those who are short on time as a way of maximising your time spent in the gym. A typical HIT session, not including your warm up, would last a maximum of 20 minutes.

Many of the benefits of HIIT training have been vastly overstated by the media and marketers but there are definitely some advantages to it.

HIIT training leads to greater EPOC (excess post-exercise oxygen consumption) when compared to continuous exercise. This means that after you have finished exercising, your body will continue to burn calories at a higher rate than normal. The evidence base is small, but at least one study has shown that you can match the training effect of continuous training in less time using a proper HIIT protocol. 

Research has also found that HIIT is a great way of improving your VO2 Max. This is essentially a measurement of how fit you are and is linked to all-cause mortality (your chance of dying). Those with a higher VO2 max have a lower risk of death compared to those with a lower VO2 max. If a proper HIIT training protocol is followed with the correct intensity (how hard you are working) and duration (how long you are working for) it is certainly a time-efficient way of improving your fitness levels.

When should HIIT training be used?

HIIT can essentially be used by anyone, unless your doctor has advised you not to partate in vigorous exercise, in which case you should aim to improve your fitness and other health markers before embarking on a HIIT training programme.

If you find continuous training monotonous, HIIT can be a great choice as the constant change of pace can keep you engaged throughout your workout.

The main reason to choose HIIT is the time efficiency compared to continuous exercise, but you must be willing to work at a hard enough intensity to compensate for the reduced time you spend exercising.

HIIT training should be very hard work when performed correctly. This intensity can be exhilarating and leave you feeling a real sense of accomplishment, but for some it won't be enjoyable. For those who want more control over how they feel during a training session, I'd recommend fartlek or continuous exercise.

20 minute HIIT workout

This workout is on a stationary or spin bike:

  • Warm up: two minutes steady cycle low resistance
  • Cycle very hard at 90% effort level for 60 seconds on a high resistance
  • Recover for 90 seconds on a low speed and resistance
  • Repeat this interval five times in total
  • Cool down: three minutes low resistance.

Repeat three times per week with at least one day recovery in between

Home HIIT workout

Warm up – do each exercise for 45 seconds

  • Jog on the spot 
  • Bodyweight squat 
  • Jog on the spot
  • Reverse lunge 
  • Jog on the spot 
  • Push ups.

Main workout – perform 3 sets of each exercise and active recovery before moving on to the next exercise

  • Squat and reverse diagonal lunge – 45 seconds
  • Active recovery (jog on the spot) – 30 seconds
  • Push up – 45 seconds
  • Active recovery (jog on the spot) – 30 seconds
  • Forward lunge – 45 seconds
  • Active recovery (jog on the spot) – 30 seconds
  • Jump outs – 45 seconds
  • Active recovery (jog on the spot) – 30 seconds
  • Plank with shoulder taps – 45 seconds
  • Active recovery (jog on the spot) – 30 seconds.

Cool down

  • Walk on the spot – 5 seconds
  • Backwards shoulder rolls (6–7 shoulder rolls)
  • Forwards shoulder rolls (6–7 shoulder rolls)
  • Reach overhead and then bend forwards – rest for 5 seconds before slowly rolling back up to standing
  • Reach overhead and lean to your right – rest for 5 seconds
  • Return to the centre and lean to your left – rest for 5 seconds
  • Return to the centre.

HIIT classes we offer

Les Mills GRIT 
Skillrun HIIT

Last updated Friday 2 September 2022

First published on Thursday 18 February 2016