New Research: Crossfit-based high intensity power training improves maximal aerobic fitness and body composition


Being an Exercise Physiology nerd, I was thrilled when I saw a scientific study on CrossFit. To the best of my knowledge this study is the first formalized, scientific examination of CF’s effect on common health parameters. I was happy to learn that CF is now becoming a subject to research, and hopefully this will contribute to an increased acknowledgment of CrossFit as a potent exercise intervention. Furthermore, future studies might help us uncover the most beneficial CrossFit inspired training regimes for different target groups. 

Below, I’ll take you through some highlights from the study. – Ditte


Crossfit-based high intensity power training improves maximal aerobic fitness and body composition


The purpose of the study was to examine the effects of a crossfit-based high intensity power training (HIPT) program on aerobic fitness and body composition.


Out of the original 54 participants, 23 males and 20 females spanning all levels of aerobic fitness completed the 10-week program. The rest (16%) dropped out of the project due to self-reported over-use or injuries. The articles describes that all subjects followed a Paleolithic type diet, but further details about this is not provided.


10 weeks of  HIPT (high intensity power training) regimen will improve VO2max and body composition in healthy adult volunteers. Furthermore, improvements of VO2max and body composition will be found across all levels of initial aerobic fitness and body composition, not only in the most overweight and out-of shape subjects.

Training Program

Subjects participated in a crossfit-based HIPT program using basic gymnastic skills (hand- stands, ring, and bar exercises) and traditional multiple-joint, functional, resistance exercises (squat, press, deadlift, Olympic lifts) performed as quickly as possible at a high intensity (low repetition, high percentage of 1-RM).

The 10-week program was varied so that some exercises were performed for a best time, and others were performed in the “as many rounds as possible” (AMRAP) style in varying time domains ranging from 10 to 20 minutes. During the strength/skill portion of the exercise session, there was no prescribed recovery time, whereas during the WOD portion of the session, subjects completed all the exercises as quickly as possible with no prescribed rest period.


Following the training program, a significant increase in relative VO2max and decrease in percent body fat were observed.


Improvements in VO2max: 43.10±1.40 to 48.96±1.42 ml/kg/min

Decreased body fat percentage: 22.2±1.3 to 18.0±1.3


Improvements in VO2max: 35.98±1.60 to 40.22±1.62 ml/kg/min

Decreased body fat percentage: 26.6±2.0 to 23.2±2.0


A very high percentage of the subjects included in this study had to quit due to injury. This questions the risk-benefit ratio for ‘extreme’ training programs like CrossFit, as the relatively small aerobic fitness and body composition improvements observed among individuals who are already considered to be “above average” and “well above average” may not be worth the risk of injury and lost training time. Further work in this area is needed to explore how to best realize improvements to health without increasing risk above background levels associated with participation in any non-high intensity based fitness regimen.

In other words, preliminary results show that CrossFit based training can improve fitness and body composition, but it can also cause over-use and injuries due to the high exercise intensity and great technical demands. This emphasizes the need to uncover/describe a training modality that one might call “clever CrossFit” – combining the high intensity functional movements with the highest possible degree of injury prevention. 

If you want to read the full study – follow this link:


8 thoughts on “New Research: Crossfit-based high intensity power training improves maximal aerobic fitness and body composition

  1. Is this the same study Russel Berger lashed out at on the CF Journal for being dishonest about the injury rates?

  2. Interesting! So 43 participants took part in the study while the other 11 pulled out due to self-reported over-use or injuries…

    This seems to be a common theme among crossfitters…injury? I recall reading and article ( trying to find it) a guy stating in one paragraph how great CF is and then spent the next two paragraphs going on to say he had not trained CF for 3 months or more due to….and went on to list all his injuries – which was a mile long…but…CF was great!

    I’m not saying CF is not great – it get’s people moving yes but is training meant to make people – or break people? Methodology v Ego?

  3. Yes, a very valid point! – that being said, ‘CrossFit’ is a lot of things. In my opinion the authors could provide us with more information about the training intervention, as the descriptions are rather vague. The same applies to information about training state / previous record of injuries of the subjects etc. All in all, the conclusion is rather “obvious” (to use a very harsh term), but the study itself raises more questions than it answers. – Ditte

  4. Due to the fact that I have been a competitive athlete since I was five, am currently a Ph. D student in the sport med field and have been working with D1 athletes for a couple of years, I may have some expertise to bring to the table. The problem is not really an issue of crossfit causes injuries, as crossfit has some very valuable training components such as plymometrics, calisthenics, free weights, etc. The real culprit, in my professional opinion, is the cleans and snatches. First of all these exercises are very unnatural movements so they do not translate well into other athletic type movements. Cleans and snatches require momentum to get it up which therefore means that you are manipulating the weight as opposed to actually lifting the weight. These exercises also neglect the eccentric contraction and therefore cheating you out of about 75% of the strength gains (approximately 75% of strength is developed in the eccentric contraction). Also because you have to use momentum to get the weight up, your joints have to bare the brunt of the load. This leads to joint swelling particularly in the wrists, hips, shoulders, and elbows and this will lead pain AND a decrease in range of motion over a span of time. So I think crossfit would be great if less emphasis was placed upon cleans and snatches, and more emphasis on the plyometrics, free weights, calithenics etc.

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