What is HIIT and what are the benefits?

If you’ve never tried high intensity interval training(HIIT) workouts, it’s worth serious consideration. Why? In short, HIIT, involves bursts of high-intensity cardio and strength exercises interspersed with very brief periods of recovery. This is then repeated for a number of sets or for a duration of time. HIIT is seen as a great way to get a big workout with multiple benefits in the smallest amount of time.

So what actually is HIIT? Well the exercises are mainly classic functional bodyweight moves such as squat jumps, burpees, press ups and weighted exercises like overhead dumbbell press and kettlebell swings. These are formed into a circuit such as a specific number of each exercise interspersed with 30 seconds of rest between each set of movements. The idea is for your heart rate to remain elevated throughout the whole routine. The routine can be made harder by decreasing the rest between sets or completing more than one full set of every exercise.

An example of a HIIT workout would be as follows.

1. 25 squat jumps onto and off a box followed by 30 seconds rest
2. 25 burpees followed by 30 seconds rest
3. 25 press ups followed by 30 seconds rest
4. 25 overhead dumb bell presses followed by 30 seconds rest
5. 25 kettlebell swings followed by 30 seconds rest.

This can then be followed with sprints on a treadmill which would be as follows.

Walk for 1 minute then sprint as fast as you can for 20 seconds then walk again for 1 minute then sprint again for 20 seconds. Do this 5 times. This exercise is helped if done with a friend as they can control your speed on the treadmill.

In total this full body workout will be around 20 minutes at the most and in that time you will have achieved a full cardio and strength based workout

The world is your oyster when it comes to variation. You can make the workout all lower body one day and upper body at your next workout. You can increase the repetitions by 5 after every workout or you can decrease the rest by 5 seconds etc etc. The aim of the game is for you to achieve the maximum amount of gains in the shortest period of time.

If this type of training is new to you I would always recommend starting slowly with a very short workout and slowly ease your way into it.  Start by doing no more than two HIIT workouts a week and gradually build up either the program or add in another HIIT workout that week.

Your body will ache is places its never ached before. The soreness you get post training is a thing called DOMS, which stands for delayed onset muscle soreness. It's a result of inflammation from the (good) damage that you have caused to your muscles from your HIIT training. The good news is that the soreness improves the more you adapt to the training. In short, the more you train, the less sore you will be.

So you may be asking why this type of workout is better than just running on the treadmill for an hour. Well its been scientifically proven that HIIT training is very efficient and this is why.

HIIT workouts shift your body from periods of aerobic activity to periods of anaerobic activity. When your body is in “aerobic mode,” your body is using oxygen. When your body is in “anaerobic mode,” your body is using its stored energy instead of oxygen. The theory behind why the shift from aerobic to anaerobic mode works is that HIIT trains your body to process oxygen more efficiently.

After a HIIT workout, your body continues to burn calories hours after due to an increased resting metabolism. This higher increased resting metabolic rate can help with weight loss and build stronger muscles with less time spent at the gym. A 20 minute HIIT workout achieves more than 60 minutes spent running on a treadmill.

You may be wondering how this happens.  Well everybody requires a minimum number of calories to live. This minimum number is called your basal metabolic rate (BMR). Your BMR is the number of calories your organs need to function while you perform no activity whatsoever. You can think of it as the amount of energy you'd burn if you stayed in bed all day.

Since your basal metabolic rate is based largely on involuntary functions like breathing and pumping blood, changes in your day-to-day activity don't do much to raise or lower this number. However, increasing muscle mass does increase BMR, because muscle is metabolically "hungry" and it takes more energy to maintain more muscle. This means that when you have a lot of muscle mass, you'll burn more calories at rest.

Also there is a term called the “afterburn effect”. The technical term for this is excess post exercise oxygen consumption.  When you are exercising, you will breathe more to provide oxygen to the working muscles. After exercise, you will continue to inspire more than normal to make up for what was used returning the body to homeostasis. So for hours after your HIIT workout, you will increase your caloric expenditure. This as been shown in studies to be double that of a steady state workout such as jogging.

So as you can see there are many benefits to shifting to a HIIT workout. The first being your time in the gym is now used efficiently. That time gained back can now be spent relaxing in the sauna.

Also your short workout achieves more benefits in that it was a full body workout and the increase in calorie expenditure after the workout accelerates fat burning. If you train fasted during a HIIT workout the fat burning effects will be improved massively.

So as you can see there are no reasons why you should at least give it a go and see how it works for you. You never know you may wonder why you never started sooner.