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.
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: http://www.ncbi.nlm.nih.gov/pubmed/23439334