Hello everyone,

My name is Aline and starting today, and every two weeks, thanks to CrossFit Courage I will have the opportunity to write about science and its connection to CrossFit and its training. My goal is to be able to bring you closer to the most important, innovative and recent publications there are about CrossFit, especially and let’s say all that information behind the knowledge of CrossFit.

These posts will consist of an article published in a well-known academic journal. It will be a simple summary for any reader. In this way, our entire community will be able to stay up to date with the latest news from our beloved world of CrossFit. Our goal is to promote science along with sport.

I hope you enjoy the initiative. We’re making this effort to make you feel more connected to the CrossFit lifestyle and give you some scientific insights into our world. So, let’s travel together in this new experience, a COURAGE WOD OF SCIENCE!

Let’s start!


I don’t know if you remember a WOD we did on a Saturday at the box called Partners in Crime. This CrossFit work of the day consisted of three for time rounds of:

  • 15/12 cal cardio (bike/rowing/ski)
  • 12 powersnatch
  • 9 burpees

Everything in SPRINT mode!

It is the perfect example to talk to you about HIIT training, high intensity interval training. Also about SIT training, speed interval training. Take a look to see what science says about these workouts!



Athletes may burn slightly more body fat with interval training than with moderate-intensity continuous training, according to a recent systematic review and analysis in the British Journal of Sports Medicine. The training intervals were shorter, which could make it easier for people to stick to them more.


Weight loss strategies typically include an increase in energy expenditure (exercise) or a decrease in energy expenditure (diet). But neither strategy appears to be effective in sustaining long-term weight changes for most people.


Some evidence suggests that interval training, including high-intensity interval training (HIIT) and speed interval training (SIT), may help people reduce body fat and lose weight more than sustained moderate exercise , even if the routine burns fewer calories. This could be because interval training increases resting energy expenditure and fat burning right after exercise, counteracting metabolic regulation.

“In this sense, high-intensity exercise may be particularly interesting for fat loss, not because of the calories expended while exercising, but because it causes your body to burn more fat after exercising,” says Professor Dr. Paulo Gentil, from the Federal University of Goiás in Brazil.


Interval training was most effective in decreasing total absolute fat mass. On average, the SIT and HIIT protocols reduced absolute total fat mass by 6.2% and 6%, respectively, compared to 3.4% for continuous moderate-intensity training.

In SIT, an average of 23 minutes was enough to reduce total absolute fat mass, in HIIT 25 minutes and in moderate intensity routines 41 minutes to reduce total absolute fat mass.

And more…

The greatest reductions in absolute total fat mass occurred when interval training was monitored, which likely increases adherence. Like in CROSSFIT With our beloved trainers!


Interval training appears to be a time-efficient approach to promoting fat loss.


What is interval training?

  • Interval training is an intermittent period of physical exertion interspersed with recovery periods.
  • High-intensity interval training requires “near-maximal” efforts performed at or above 80% of maximum heart rate or the equivalent of maximum oxygen consumption.
  • Sprint interval training requires “full” efforts performed at or above maximum oxygen consumption.

More articles

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