Posted on October 31, 2023 by Kate Halsall

We all know that High Intensity Interval Training is great for torching calories, reducing body fat and improving general well-being. But then we came across this question online “Can you really burn 1000 calories doing 20 minutes of HIIT?” and we accepted the challenge!

The workout is on the link here. It was inspired by the training I’m doing to compete in my first ever hyrox in November. I worked my absolute backside off! The result – 177 calories! I then tracked my calories for 20 minutes of my spin class that I teach – that came in at 188. Intrigued, I also tracked the calories for 20 minutes of a Zumba class I was covering – that was 173 calories, and a 3km interval run on the treadmill burnt 200 calories.

So I burnt 200 calories or less – What does it mean?

  • Everyone burns calories at different rates. Age, gender, body composition – they all play a part in how many calories we burn.
  • The intensity of the activity being performed. The more intense an activity is the more calories an individual burns.
  • Your workout routine. Your body adapts to workout routines, and it becomes easier. Eventually you’ll burn fewer calories while engaging in the same workout. If you want to burn more calories, you need to change your routine. As an example, I teach spin 4 times a week and have been training for Hyrox for a number of months now, but I don’t run hard regularly (although I should be!) which may be why the calories are different here.
  • EPOC (Excess Post-Exercise Oxygen Consumption) or ‘afterburn’. It means that whilst we burn calories during the workout, we can burn between 25-30% MORE after the workout when we are at rest. Maybe not enough to claim 1000 calories as a result of 20 minutes of work, but definitely enough for 500!


The results speak for themselves.

To do a real thorough test, I would have to do no exercise at all on one day and record what my overall calorie burn for that day is. The next day I would need to just do this workout and nothing else, and record my overall calorie burn for that day and compare the two. In this job – not exercising is simply not an option (plus I love it!).

But hey, this was just a bit of fun! If you’re interested, why not give the workout a go? Or, alternatively, here is another 20 minute HIIT workout to try.