2016 IMPORTANT UPDATE
The NSCA has issued an erratum to the study that was originally the source of this discussion.
https://www.nsca.com/media-room/press-releases/nsca-announces-correction-to-published-article/
NSCA Announces Correction to Published Article
The following erratum, a correction to a published article, appears in the October 2015 issue of the Journal of Strength and Conditioning Research.
The following erratum, a correction to a published article, appears in the October 2015 issue of the Journal of Strength and Conditioning Research. A panel of reviewers has examined new information regarding questions raised on the reasons described in the article for subjects not completing the study.
The National Strength and Conditioning Association is issuing the erratum on the recommendation of the reviewers. Other than as is described in the erratum, this change does not affect the overall conclusion of the study.
Erratum:
In reference to Smith, MM, Sommer, AJ, Starkoff, BE, and Devor, ST. CrossFit-based high-intensity power training improves maximal aerobic fitness and body composition. J Strength Cond Res 27(11): 3159–3172, 2013, the authors have stated that the reasons for participants not completing follow-up testing, as reported in the article, were provided to the authors by the club owner. The club owner has denied that he provided this information.
After the article was published, 10 of the 11 participants who did not complete the study have provided their reasons for not finishing, with only 2 mentioning injury or health conditions that prevented them from completing follow-up testing.
In light of this information, injury rate should not be considered a factor in this study. This change does not affect the overall conclusion of the article.
The erratum can also be found here.
Note from the Editor:
If you are involved in any aspect of exercise then you know there is a a pro crossfit group and an anti crossfit group with a few in the middle who either do not care or choose to remain unbiased. Recently the NSCA published a study about crossfit style training and analyzed the results.
Link to Study ← — — — Click Here
Here is the study breakdown:
What comes to mind when you hear the word “Crossfit”? Is it an image of some jacked guy doing the Clean and Jerk on ESPN at the Crossfit games? Or maybe an injury and lawsuit waiting to happen like this video:
Is it a program that you can follow your whole life or just a very popular fad? As much as I would love to spill out my personal views on Crossfit and its applications, I will refrain. I am here to analyze and offer an unbiased breakdown of a recent research publication and its applications because let’s be honest…there are very few people that are not either strongly for or against Crossfit. I hope that this may help you make a better informed decision if you are looking at joining a Crossfit gym, already doing Crossfit, or you think it’s a waste of time and energy and just want to know how it affects the human body.
CROSSFIT…What Are You?
Crossfit-based high intensity power training improves maximal aerobic fitness and body composition.Sounds good and simple right? But what is High-Intensity Power Training or HIPT? IF you have ever ran wind sprints or hill sprints, then you likely completed High-Intensity Interval Training (HIIT) which is an excellent alternative to continuous running at a steady state (jogging). HIPT uses the same the same concept of work to rest intervals but uses varied, multiple joint movements such as squats, deadlifts, pull ups, overhead press, and Olympic lifts and its variations instead of running. For instance, a common procedure for a HIPT session or a Crossfit “WOD” (workout of the day) may consist of a few select exercises performed at a relative high resistance either for a best time or “as many rounds as possible”.
The study had participants complete a 10 week Crossfit-based HIPT training program. The variables the study examined were aerobic fitness measured by VO2 and Body composition aka body fat percentage. VO2 is a measure of how much oxygen your body can consume. As this number increases, it shows you are in better aerobic shape.
Give me the results already!
“A 10 week crossfit based HIPT program significantly improves maximal aerobic capacity and body composition in individuals of all fitness levels and genders.”1
The study showed that this 10 week program helped the participants drop approximately 3.7% body fat across all individuals as well as an improvement of 13.6% and 11.8% in VO2 max for men and women respectively. An important statement to note is that even with the highly trained individuals, they experienced an increase in VO2 max. This is important because continuous aerobic training and HIIT have not been shown to consistently improve VO2 max of highly trained individuals.OMG That’s so amazing…let’s all go do Crossfit!
***THE FINDINGS BELOW WERE THE STATEMENTS OF ERROR AND REMOVED FROM THE STUDY. aka. were not found to be true. ***
Not so fast! There are a few more observations that I must share with you. First, this study had 43 individuals complete the 10 week program. However, the study began with 54 participants. Of these 54 2 had to drop out due to time constraints and 9 dropped out citing overuse or injury. 16% of the participant base had to drop out due to overuse or injury…in only 10 weeks! This high number still occurred under the supervision of certified fitness professionals and deliberate periodization (rest and recovery workouts were implemented to help prevent overuse).
This is a very high number and calls into question the risk vs. reward ratio for such a program. The researchers advised that it may not be worth the risk for “above average” and “well above average” fitness populations to complete such a program for the relatively small improvements seen in this study. Also of note, not all of the body composition changes can be attributed due to the Paleolithic type diet of the participants. However, since the participants were utilizing the same diet before the program, one can still infer that the program has a role in reducing body fat.
Crossfit HIPT programs are a good method for increasing aerobic fitness levels and reducing body fat. The downside is a very high risk of overuse and/or acute injury. (injury risk conclusion is not accurate according to the corrections made by the NSCA.)
Originally published at fitletes.com.