Why You Should Do HIIT

Interval training is great when used wisely. It consists of near max-effort periods and low effort periods. It allows you to push yourself to your limits, and recover throughout the low intensity periods.

However, to be effective HIIT must be done correctly. If you have read my “Why I Became a Personal Trainer”, you will know that I have used and abused interval training. I used to do 30-40 minutes of HIIT training per day, and I got very little results.

This was because I wasn’t doing it correctly.

Studies have proven that in order for HIIT to be effective, you must reach between 80-100% of your VO2max (a measure of the maximum volume of oxygen the body can use).  Basically meaning, you have to work very hard!

Many people will trudge through 20-30 minutes of HIIT, but not realise that they are not reaping the benefits of this type of training as they are not working hard enough. You could do 5-10 minutes of interval training and work your ass off and burn more calories than if you were to do 30 mins half heartedly. This is also why people who do interval training over low intensity training tend to lose more fat in the long run (excluding diet), as they burn more calories.

The University of Western Ontario lead a study to reveal the effects of interval training and low intensity training on body composition. The study used ten males and ten females training three times a week. One group would do 4-6×30 second sprints on the treadmill, and the other group would do 30-60 minutes of low intensity steady state cardio at the “fat burning zone”.

The results showed that the group doing the interval training lost more fat over six weeks

Although this result may seem to tell you that if weight loss is your goal, you should be doing HIIT, both high intensity exercises and low intensity exercise have their benefits. They are tools which can help you lose fat, however these should be seen as tools to be used alongside a healthy, and most importantly consistent diet and active lifestyle.

Additionally, if you are a distance runner, HIIT can push your aerobic capacity and allow you to run faster over long periods of time. This is why it is important to use interval training alongside distance training to push your body to progress and adapt, which will result in faster times overall. 

Some of the benefits of HIIT include:

  1. Increased BMR (basal metabolic rate) up to 24 hours after exercise
  2. Higher levels of fat oxidation within muscles
  3. Improved insulin sensitivity in muscles
  4. Sufficient spikes in growth hormone levels (aiding in fat loss) and catecholamine levels (which are chemicals in your body that are produced to mobilise fat stores for burning)
  5. Increased appetite suppression post exercise

Different types of Interval Training

  • Sprints on cardio vascular machines: this can be done on anything, the treadmill, bike, cross trainer, rowing machine etc. and it is really important to mix it up and keep your body guessing. When our bodies become used to an exercise it does not use as much energy as it once did as it has adapted to that type of training. When you incorporate something new into your training, your body will initially struggle as it will not be used to working those muscles.
  • Circuit based training: this is my personal favourite when it comes to HIIT as you can incorporate so many exercises in this. For instance, you could take two upper body exercises (press ups and pull ups) and two lower body exercises (walking lunges and squats) and do 30 seconds on 30 seconds off for 4 rounds. So, 30 seconds press ups, 30 second rest, 30 second walking lunges, 30 second rest…etc. I would recommend you mix up the upper and lower body exercises to get your heart rate up.
  • Plyometric training: Plyometric, also known as “jump training” links back to the circuit based training as it can take the same format; 30 seconds on, 30 seconds off. There are hundreds of different plyometric exercises such as squat jumps, lunge jumps, burpees. Plyometric training is great for building power as your muscles are exerting maximum bursts of energy and force for short periods of time. You can also do a tabata style workout including plyometrics (20 seconds max effort, 10 seconds rest for 8 rounds).
  • Swimming: As a former swimmer, I can vouch that it is an extremely tough sport, especially when you are doing sprints. Swimming can be a very low intensity sport, and is good for injured people as it puts little pressure on the joints. However, it can also be a lung buster! An example of interval training in swimming would be 1 or 2 length maximum speed, 30 seconds rest. Aim for 5-10 rounds depending how experienced you are. Remember to always warm up and cool down.