I preface this with the following disclaimer: this blog entry is not an accusational rant or advertisement pertaining to one mode of fitness over the other. It is simply my perspective on a fitness movement that has gotten my attention. I am sharing my opinions, not to marginalise myself, but to shed light on the positive and negative evidence and to provide a holistic view in order to provoke thought on the topic.
CrossFit (according to the CrossFit Manual) can be defined in the following way:
The CrossFit prescription is “constantly varied, high-intensity, functional movement.” Functional movements are universal motor recruitment patterns; they are performed in a wave of contraction from core to extremity; and they are compound movements—i.e., they are multi-joint. They are natural, effective, and efficient locomotors of body and external objects. But no aspect of functional movements is more important than their capacity to move large loads over long distances, and to do so quickly. Collectively, these three attributes (load, distance, and speed) uniquely qualify functional movements for the production of high power. Intensity is defined exactly as power, and intensity is the independent variable most commonly associated with maximizing favorable adaptation to exercise. Recognizing that the breadth and depth of a program’s stimulus will determine the breadth and depth of the adaptation it elicits, our prescription of functionality and intensity is constantly varied. We believe that preparation for random physical challenges—i.e., unknown and unknowable events— is at odds with fixed, predictable, and routine regimens.
Some favourable observations.
Multi-joint exercises at high intensity: From the perspective of a fitness professional, any movement or exercise regime that encourages multi joint exercises at high intensities and encourages the general public to be healthier, fitter and stronger is a successful mode of exercise. CrossFit advocates the use of the big muscle groups, with multi-joint exercises, these exercises are the mother of all lifting patterns such as, the squat, the deadlift, and multiple Olympic lifting movements. These exercises are regarded as functional exercises which mean that they are the muscles that we use everyday from picking up furniture to playing with your kids. Functional exercises like the squat and deadlift etc enhance these everyday functions whilst reducing the risk to injury. In addition, they produce massive hormonal responses incurring multiple advantages in regards to muscle mass, fat loss, and neurological strength.Culture and camaraderie: CrossFit focus on intensity during their workouts. They do this by submitting workouts under time goals and incorporating competitions, which is a great way to boost the competitive juices and increase the intensity of a workout which maximises what you get out of your session. In turn, it produces a positive culture and a great sense of camaraderie which, as we all know, positively influences health and fitness goals. Science has found that positive culture and support can enhance performance by up to 10%.
Instructional technique: According to the CrossFit manual, the technique instruction has some serious rigour. It seems to translate into practice also as I have witnessed that several of my colleagues (who are CrossFit affiliated) are highly diligent in their technique and correction. In addition, there are CrossFit establishments around the world who have put together remarkable mobility and flexibility exercises which enhance physical preparedness. San Francisco CrossFit, which is held as the premier of all CrossFits in the world, boasts superior mobility, flexibility and pre-hab exercises that benefit anyone who is active.
The Science
Since CrossFit is a relatively new phenomenon, there is not an exhaustive amount of independent and longitudinal research available. However CrossFit address the fact that a constant variety of exercises stimulates positive physiological adaptations:“Recognizing that the breadth and depth of a program’s stimulus will determine the breadth and depth of the adaptation it elicits, our prescription of functionality and intensity is constantly varied. We believe that preparation for random physical challenges—i.e., unknown and unknowable events—are at odds with fixed, predictable, and routine regimens.”
This statement has been based on a belief, rather than scientific fact. There is, however, one piece of positive independently sourced and peer reviewed research that was performed by Smith, Sommer et al. 9000. During this study, significant improvements in VO2max and lactate thresholds of CrossFit participants studied were found which is a high sought after result for any fitness regime.
The adverse observations.
Here, I will present some of the favourable observations in a different light.When culture becomes ‘Cult’: While I admire CrossFit’s ability to nurture a positive culture and camaraderie, I have witnessed, first hand, when this manifests into a cult-like society that refutes all other forms of exercise. I’m talking about the notion that “if you’re not participating in CrossFit, you’re doing it wrong.” This is not to say it doesn’t happen in other sports, but for now we are talking about CrossFit. During my time in this industry, I have learned that any sporting body, fitness professional or participant that is able to maintain an open mind and a low ego will produce sustainable results and last the test of time.
When random programming reaches the point of diminishing returns: Training for the unforeseeable by constantly varying workouts can result in marginal adaptations, as was found in Smith, Sommer et al’s article. However, it does not result in maximal adaptations. Kraemer, Stone, Hakinen, Newton and Haff (check these guys on Google scholar, they are the leaders in the strength and conditioning industry) have proven that to maximise adaptation you MUST stick to a stimulus for 3-6 weeks to allow for physiological parameters to take place. Constant changing of the stimulus won’t allow the system to completely recover and adapt, hence minimising the amount of gains. This notion forms the very foundation of all program formation and how we have come to implement health and fitness results for our clients.
Prevalence of injury: CrossFit incorporates Olympic lifting (clean and jerks, snatches etc.) in to metabolic sessions. These lifts are highly complex and place a great strain on the nervous and musculoskeletal system. While they are terrific exercises and the most effective at increasing strength and power, they are not suited to the CrossFit format. In order for these exercises to be effective they must be performed at challenging loads with minimal reps. As the very nature of Olympic lifts are highly complex, it is impossible for form to be maintained after 6 reps. Some CrossFit workouts contain up to 30 snatch’s or clean and jerk movements coupled with high intensity runs and many other demanding metabolic exercises. When the reps aren’t performed correctly the body will recruit bad movement patterns to help with the lift. This is turn produces injury. It may not happen straight away, but it will. Smith, Sommer et al confirmed this in their study where they reported that 19% of all participants in the study had ascertained an injury. That is 1 in 5 people. No matter what sport you play, this is an unacceptable result. In fact, in a Consensus Paper by the Consortium for Health and Military Performance (CHAMP) and the American College of Sports Medicine (ACSM) the potential emerging problem associated with extreme conditioning programs (ECPs) such as CrossFit has been identified by the military and civilian communities. This is because of the disproportionate musculoskeletal injury risk from, particularly for novice participants, resulting in lost duty time, medical treatment, and extensive rehabilitation.
The wrap up.
I believe that CrossFit enhances fitness and strength, but at a high cost. It is an exciting, motivating and radical movement which inspires thousands of people worldwide. In this generation of obesity and poor movement strategies, that can only be a good thing. I don’t, however, believe it is the most effective or sustainable way to achieve fitness. It allows for bad movement patterns which result in a high injury prevalence which is unacceptable. Additionally, if you are injured you are more likely to minimise future activity and you start to experience diminishing returns.I believe CrossFit-type training has its place in the greater eco-system that is your fitness. My advice is to stick to a structured and periodised weight regime, implement metabolic (CrossFit) sessions as long as there is no Olympic lifting, whilst finding time for High intensity interval training. As this is the hierarchy of health and fitness and the most effective, scientifically proven way to MAXIMISE fitness, reduce body fat, increase strength which ultimately reduces the risk of injury. My parting words: “Weak things break, Strong things don’t.”
Reference.
Smith, M. M., A. J. Sommer, et al. (9000). "Crossfit-based high intensity power training improves maximal aerobic fitness and body composition." The Journal of Strength & Conditioning Research Publish Ahead of Print: 10.1519/JSC.1510b1013e318289e318259f.The purpose of this study was to examine the effects of a crossfit-based high intensity power training (HIPT) program on aerobic fitness and body composition. Healthy subjects of both genders (23 males, 20 females) spanning all levels of aerobic fitness and body composition completed 10 weeks of HIPT consisting of lifts such as the squat, deadlift, clean, snatch, and overhead press performed as quickly as possible. Additionally, this crossfit-based HIPT program included skill work for the improvement of traditional Olympic lifts and selected gymnastic exercises. Body fat percentage was estimated using whole body plethysmography and maximal aerobic capacity (VO2max) was measured by analyzing expired gasses during a Bruce protocol maximal graded treadmill test. These variables were measured again following 10 weeks of training and compared for significant changes using a paired t-test. Results showed significant (P<0.05) improvements of VO2max in males (43.10+/-1.40 to 48.96+/-1.42 ml/kg/min) and females (35.98+/-1.60 to 40.22+/-1.62 ml/kg/min) as well as decreased body fat percentage in males (22.2+/-1.3 to 18.0+/-1.3) and females (26.6+/-2.0 to 23.2+/-2.0). These improvements were significant across all levels of initial fitness. Significant correlations between absolute oxygen consumption and oxygen consumption relative to body weight was found in both men (r=0.83, P<0.001) and women (r=0.94, P<0.001), indicating HIPT improved VO2max scaled to body weight independent of changes to body composition. Our data shows that HIPT significantly improves VO2max and body composition in subjects of both genders across all levels of fitness. (C) 2013 National Strength and Conditioning Association
x
