CrossFit Controversies: Risk vs. Reward
THE BENEFITS
The benefits of CrossFit are under-researched in a long-term capacity, however, a number of studies have determined the potential benefits of this type of high-intensity functional power training on aerobic capacity and body composition. High-intensity interval training is desirable to many individuals looking to improve fitness levels with minimal time commitment to training. Typically, these types of workouts take a very short amount of time, averaging between 5 and 20 minutes, and reap maximal caloric burn due to the continuous nature of the workload, relative intensity, and minimal rest periods. In some workouts, participants target achieving as many rounds or reps as possible before the allotted time is up, whereas other workouts request the best time to completion of a given set of exercise rounds. A combination of power and Olympic lifts, cardio activity, gymnastics, and other bodyweight movements, is used to stimulate positive adaptation of maximum aerobic capacity and body composition.
Smith, Sommer, Starkoff, & Devor (2013) prove such an example in their study on the effects of CrossFit-based high-intensity power training (HIPT) on body composition and aerobic fitness. The 10-week HIPT program consisted of both traditional power and Olympic lifts including squat, deadlift, clean, snatch, and overhead press, however, performed in a non-traditional fashion of completing the designated number of repetitions as quickly as possible (Smith et al., 2013). After HIPT training, body fat was reduced by 3.7% across all individuals, in both male and female categories (Smith et al., 2013). Oxygen consumption relative to body weight increased in all participants, resulting in a 13.6% and 11.8% improvement in VO2 max for men and women, respectively (Smith et al., 2013). This was independent of the changes in body mass, which is often attributed to the improvements in oxygen capacity (Smith et al., 2013).
CROSSFIT vs. NSCA
In this study, 16% of participants did not complete the program or return for follow-up testing (Smith et al., 2013). Although this limitation was expressed in a paragraph noting the potential for injury risk when partaking in this type of exercise, it was never claimed that the reason for the 16% failure was injury or overuse. This makes the claims staked by the defendant (CrossFit, Inc.) in the case of CrossFit vs. the National Strength and Conditioning Association (NSCA) completely invalid. This study, which is published in favor of CrossFit-style HIPT in the NSCA’s primary educational resource, the Journal of Strength and Conditioning Research, states as follows (Smith et al., 2013):
“A unique concern with any high-intensity training program such as HIPT or other similar programs is the risk of overuse injury. Despite a deliberate periodization and supervision of our Crossfit-based training program by certified fitness professionals, a notable percentage of our subjects (16%) did not complete the training program and return for follow-up testing. Although peer-reviewed evidence of injury rates pertaining to high-intensity training programs is sparse, there are emerging reports of increased rates of musculoskeletal and metabolic injury in these programs (1). This may call into question the risk-benefit ratio for such extreme training programs, 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.”
CrossFit, Inc. proceeded to berate the NSCA for making false claims which were unlawful, unethical, and unfair. The highly biased preliminary statement presented in this case by the defendant bases its accusations on the NSCA’s “stagnant brand” and “supposedly scholarly journals” which aim to undermine their biggest competition. The defendant proceeds with the following allegations:
“Whereas the NSCA’s and ACSM’s decades-long stranglehold on fitness has resulted in a country that is generally considered to be out of shape – if not downright obese – CrossFit has gained a massive following in recent years precisely because it achieves better and faster results than traditional forms of fitness training. In short, it succeeds where the traditional fitness establishment has failed.”
These widely overarching claims that the NSCA and ASCM are at the ultimate fault of our country’s failing health, can largely be considered disrespectful and unreasonable. Moreover, the discerning fact that CrossFit is a $4 billion-dollar industry, and CrossFit, Inc. being a $100 million for-profit company lacking an established training principle in evidence-based program design, and the NSCA is a non-profit educational catalyst for practical, peer-reviewed research to serve the public and its certified fitness professionals, makes these claims even less reliable. While I do see the attraction to this type of exercise for the general population, I have a hard time supporting an organization that makes false claims in an attempt to undermine the reputability of the NSCA’s scientifically unbiased principles and methodology.
SAFETY CONCERNS
With more than 13,000 CrossFit gyms (or “boxes”) established throughout the country, intense scrutiny should be placed on this company’s mission and training principles in order to decipher whether or not this is an efficacious and safe form of athletic conditioning. Any emerging form of exercise or dieting should be challenged on the basis of evidence-based practice in order to properly validate and promote programs that are both safe and effective for the long-term health and well-being of all participants, with long-term being the keyword here.
In a review of the pros and cons of extreme conditioning programs such as CrossFit, a 2013 survey was referenced in which CrossFit participants were asked to disclose any injuries that had prevented them from working, training, or competing over the past 19 months (Knapik, 2015). The survey 132 respondents averaged 5.3 hours/week during this time, and 74% claimed to have sustained an injury during that time, 7% having an injury that required surgery (Knapik, 2015). The most common injuries were distributed to the shoulder (32%), spine (28%), and arm (20%) (Knapik, 2015).
Other cases have been reported for exertional rhabdomyolysis and carotid artery dissection (CAD) in association with CrossFit activity (Knapik, 2015). The four cases of CAD were attributed to lifting significantly more weight than previously done (20% more) and/or to performing exercise which involved rapid, twisting movements (Knapik, 2015). CAD can result in a partial blockage of the carotid artery, a partial tear in the vessel wall resulting in a hematoma, or a total rupture and subsequent aneurysm, with the goal of treatment being the reduction of neurologic deficits and the stability of blood flow (Knapik, 2015). Repetitive eccentric contractions produce muscle damage that leads to exertional rhabdomyolysis (Su, 2008). Extreme muscle breakdown results in leakage of muscle enzymes, including creatine kinase, lactate dehydrogenase, and myoglobin, and electrolytes such as potassium. When the level of myoglobin in the blood exceeds 3mg/L, it spills into the urine (termed myoglobinuria) and produces a tea/cola coloration (Su, 2008). Myoglobin damages renal tubules, which can lead to tubular necrosis, and if renal blood flow is further limited by a high exertion level and dehydration, the kidneys are less capable of clearing the muscle breakdown products which can lead to fatal complications (Su, 2008). The very nature of CrossFit workouts brings an increased likelihood for these injuries of ‘overexertion’ to occur.
Weisenthal et al. (2014), conducted a similar survey via the main CrossFit website reaching 386 participants meeting the inclusion criteria for CrossFit participation. Data from the study concluded that the injury rate over the prior 6 months was determined to be 19.4% having had at least one injury across all individuals, with males being injured more frequently than females. The shoulder was the most commonly injured body part during gymnastic movements, while the lower back was most often from powerlifting movements, without having had prior discomfort in that area (Weisenthal et al., 2014).
High-risk should not be confused with “ineffective,” since most all exercises provide benefit in some manner; though, the aim of exercise should always be to maximize benefits and minimize risks (Mullins, 2015). Two very high-risk exercises commonly performed in a CrossFit setting are unassisted pistol squats and kipping pullups, both of which are rarely able to be performed with proper execution (Mullins, 2015). In the pistol squat, the lordotic curve of the lumbar spine should be maintained, the knee should track over the toes with virtually no mediolateral shift, and the heel should remain in contact with the ground (Mullins, 2015). Rounding of the back is a compensatory mechanism used to achieve depth in the pistol squat and places unnecessary strain on the lower back (Mullins, 2015). Kipping pullups result in lumbar hyperextension, unlike traditional pull-ups which allow the spine to stay neutral (Mullins, 2015). Hyperextension of the spine has long been contraindicated by medical professionals due to the high potential for injuring the spinal discs, nerves, and joints (Mullins, 2015).
The incidence of injury was reported to be much less when an individual was working with a trainer, and the lower female incidence rate can be attributed to their likelihood of seeking a coach prior to training (Weisenthal et al., 2014). With nearly a 20% injury rate, however, the jury is still out on whether or the risk-benefit ratio is in an athlete’s favor. Similar rates of injury are seen in the sport of gymnastics and on the Power/Olympic lifting scenes.
ESTABLISHED RECOMMENDATIONS
Assigning high volume repetitions and speed to technically-demanding exercises opposes USA Weightlifting’s recommendation to keep “repetitions to three or less on technical exercises [Olympic movements] and five or less for strength exercises (e.g. squats), and never continue repetitions if form is breaking down” (Mullins, 2015). The entire foundation of CrossFit is based around a total-body fatigue, forced-adaptation model, risking form break-down and injury with every repetition that passes. The NSCA aligns with the USAW philosophy, and stressed the importance of exercise order for maximal adaptation gains and the insurance of safety (Mullins, 2015):
“Power exercises require the highest level of skill and concentration of all the exercises and are most affected by fatigue. Athletes who become fatigued are prone to using poor technique and consequently are at higher risk of injury. The explosive movements and extensive muscular involvement of power exercises also result in significant energy expenditure. This is another reason to have athletes perform such exercises first, while they are still metabolically fresh.”
In the majority of CrossFit programs, this rule is ignored, and one can find high repetition power and strength exercises interspersed with more high volume multijoint movements which ultimately leads to the exhaustion of all metabolic systems. The body responds with generalized fatigue and poor recovery, thus generalized and incomplete adaptation between workouts. The focus of this company’s mission going forward should place an emphasis on educating its athletes on the proper execution of movement as well as the risks involved when undertaking this inherently intense form of activity.
TARGET POPULATIONS
Some CrossFit facilities are run by well-educated, exercise science professionals who make an effort to ensure all participants are practicing safe techniques and sound progressions with individualized program design. One such individual is Dr. Mike Young, Director of Performance and Research with Athletic Lab in Cary, NC. When incorporating CrossFit programming into his Sports Performance and Athletic Development facility, he takes the following approach:
“I look at health on a continuum with a diseased state being on one side, healthy being somewhere in the middle, fit being somewhere beyond that, and performance-oriented on the far side of the continuum. Generally speaking, I'd say CrossFit is best for people in the middle. I don't think it's appropriate for people who are not yet ready for intense training. Likewise, it's not appropriate for the more specific training that CrossFit, by its very nature, does not provide.”
It is one thing to teach a skill, but it is an entirely different entity to be able to teach and skill and to be able to explain why this skill is applicable in a performance capacity and how it fits into an athlete’s long-term progression. If one cannot back up a workout or an exercise on a physiologically sound basis for future adaptation and progression, it has no business being executed. Creating generalized adaptation and aerobic conditioning may have its place in the general population of untrained to moderately trained, non-competitive individuals provided the risk remains low, but it has no place in the sport-specific world of athletic training. On this topic, Dr. Young states:
“When training for sport, I recommend training progress from general to specific over the course of a training program. Likewise, I generally suggest that intensities start lower and progressively increase over the course of the season. Finally, I like to see volume operate inversely to intensity over that time. So intensity and volume should rarely, if ever, be high concurrently. CrossFit has the potential to violate all of these recommendations.”
I would be surprised to hear a coach of any professional athlete state that he or she plans “workouts of the day” which have no sequence or progression in an annual training program, macrocycle, or even microcycle of program design in order to achieve peak athletic performance. The importance of specificity in training cannot be emphasized enough when working with high-level athletes. Generalization will only get you so far in developing top-level sport skills and efficiency. Too often coaches neglect to research what methods they should be using for optimum training benefit per individual and instead operate off of traditional conditioning programs that serve an entire team of individuals. In my opinion, general training creates general athleticism and average athletes. In an effort to challenge CrossFit’s claim to be a “survival of the fittest” sport, the world’s most elite athletes across all professional sports train, and always have trained, on the basis of “survival of the smartest” in order to preserve their longevity in sport and maximize peak performance via specifically calculated and cyclical, periodized programming.
References
CrossFit v. National Strength and Conditioning Association, No. 3:14-cv-01191-JLS-KSC (S.D. Cal. May 12, 2014).
Knapik, J. J. (2015). Extreme Conditioning Programs: Potential Benefits and Potential Risks. Journal Of Special Operations Medicine: A Peer Reviewed Journal For SOF Medical Professionals, 15(3), 108-113.
Mullins, N. (2015). CrossFit: Remember What You Have Learned; Apply What You Know. Journal Of Exercise Physiology Online, 18(6), 32-44.
National Strength and Conditioning Association. (n.d.). NSCA update to CrossFit Inc claims and allegations.
Smith, M. M., Sommer, A. J., Starkoff, B. E., & Devor, S. T. (2013). Crossfit-based high-intensity power training improves maximal aerobic fitness and body composition. Journal of Strength and Conditioning Research, 27(11), 3159- 3172.
Su, J. (2008). Exertional rhabdomyolysis. Athletic Therapy Today, 13(5), 20-22.
Weisenthal, B. M., Beck, C. A., Maloney, M. D., DeHaven, K. E., & Giordano, B. D. (2014). Injury Rate and Patterns Among CrossFit Athletes. Orthopaedic Journal Of Sports Medicine, 2(4), 2325967114531177.