By Dr. Mercola
CrossFit, created by Greg Glassman, is an intense strength and conditioning program involving perpetually changing and challenging intervals of aerobics, body weight exercises, gymnastics and Olympic weight lifting. It’s a workout that Glassman says will “deliver you to your genetic potential.” CrossFit is among the most extreme forms of exercise out there, and I advise using caution if you decide to try it, as any exercise done incorrectly can easily lead to injury.
Part of the company’s success is that anyone who wants to open a CrossFit gym (referred to as “a box”) can do so, provided they fulfill the company’s requirements for affiliates, which includes a $3,000 annual fee, proof of insurance and passing a two-day certification course, in which trainers must demonstrate ability to perform, coach and correct CrossFit’s movement techniques.
While a two-day course may not sound like much, CrossFit’s certification is actually more comprehensive than most other personal trainer certifications — many of which do not include exercise-related classroom education, in-person practical education or practical hours to maintain certification. CrossFit’s credentials require all of the above.
As a brand, CrossFit has fought hard to protect its reputation against nay-sayers who claim it’s just too dangerous. That includes suing researchers who reported that some of the participants dropped out of the CrossFit study due to injuries. In September, 2016, the judge in the case ruled1 the researchers’ claim was in fact false, as all subjects in the study swore they were not injured as a result of the training.
Clearly, extreme sport has risks, and the nature of CrossFit can heighten the risk of injury if you’re not taught correctly from the start, or fail to heed your own limits. Glassman has even gone on record saying,2 “It can kill you. I’ve always been completely honest about that.” CrossFit is not for everyone, but then again, no extreme sport is. That said, there’s no denying it can be effective if and when done with proper form and some common sense. In fact, in a gym with good trainers, it may be one of the best fitness programs out there.
Proper Body Mechanics is Crucial for Safe CrossFit Practice
Kelly Starrett, one of the leaders in the CrossFit movement, was previously featured in another 60-Minute segment on CrossFit, in which he stressed the importance of proper body mechanics, both in and outside the gym. He's also the author of the book “Becoming a Supple Leopard,” which is an excellent resource for exploring and addressing biomechanical inadequacies that might increase your risk of injury.
I interviewed him about his views on CrossFit and body mechanics in 2014. According to Starrett, the central tenet of CrossFit is to help you move and function at full capacity, expressing “all the things a human being should be able to do.” For example, can you squat all the way down with your feet and knees together, feet flat on the floor? That’s an expression of full hip motion. Most people can't do that without falling over or lifting their heels.
Starrett views movement as a convenient diagnostic tool. Once you come up against the limits of your range of motion and capacity, you know where your problem is, and where you need to focus your attention. Having good range of motion and flexibility is particularly important when you're engaging in high intensity exercises, which I believe are foundational for optimal health and fitness.
CrossFit Injury Rates Comparable to Conventional Fitness Training
While there’s a slim supply of studies looking at CrossFit’s safety, a couple have helped shed light on its injury rates. A 2013 study,3,4 electronically published ahead of print in the Journal of Strength and Conditioning Research,found that nearly 75 percent of CrossFit participants sustained some form of injury. The most common injuries involved the spine and shoulders. Of 186 reported injuries, nine ended up requiring surgery.
However, once that injury percentage is placed in the context of time spent training, CrossFit actually turns out to have an injury rate comparable to conventional fitness training. Overall, the injury rate was 3.1 per 1,000 hours. As noted by the authors:
“Injury rates with CrossFit training are similar to that reported in the literature for sports such as Olympic weight-lifting, power-lifting and gymnastics and lower than competitive contact sports such as rugby union and rugby league … Comparing adult fitness activities, including general gym/fitness club training; and long, middle and sprint distance running and triathlon training, the injury rates are also broadly similar to CrossFit training.”
For whatever reason, this study never went on to official publication. Still, it appears to be the first paper to address CrossFit injury rates specifically. Also, while extreme sports such as CrossFit can trigger rhabdomyolysis, commonly referred to as rhabdo,5 no such incidence was found in this group. Rhabdomyolysis occurs when muscle fibers are pushed to the point of breaking down and entering your blood stream, a condition that can lead to life-threatening kidney damage.
While rare, rhabdo can result from just about any high-intensity exercise where you push yourself beyond your individual limits. CrossFit does try to raise awareness about the condition6 — its early warning signs, how to prevent it, and its ultimate dangers, which anyone delving into extreme sports should be aware of.
Other Research Confirming CrossFit Safety Is On Par With Other Common Exercises
A more recent study7 published in Orthopaedic Journal of Sports Medicine found an injury rate of about 20 percent, with low-back, shoulder and knee injuries being the most common. According to the authors:
“The involvement of trainers in coaching participants on their form and guiding them through the workout correlates with a decreased injury rate. The shoulder and lower back were the most commonly injured in gymnastic and power lifting movements, respectively. Participants reported primarily acute and fairly mild injuries.”
After being criticized for their use of “injury rate” without specifying whether this referred to incidence or prevalence, the authors published a response8 clarifying their use of injury rate as a measure of prevalence, since exposure hours was not included in the initial paper. The calculated injury rate in terms of incidence was 2.4 per 1,000 hours, which they noted:
“… is slightly less than what other studies have reported on CrossFit of 3.1 per 1,000 hours. In comparison, it is higher than less metabolically stressful activities such as walking, cycling to work, gardening, home repair, hunting and fishing, golf, dancing, swimming, walking and rowing, which have reported injury rates of 0.19 to 1.5 per 1,000 hours.
However it is lower than the exposure times for contact or team sports such as squash, judo, wrestling, karate, basketball, soccer, ice hockey and volleyball, which have reported injury rates of 6.6 to 18.3 per 1,000 hours.
To compare our results to running, one study showed an injury rate of 2.4 per 1,000 hours in long-distance/marathon runners and about double that in sprinters and middle-distance runners (5.6 to 5.8 per 1,000 hours), although the numbers on these specific sports can vary greatly depending on the study (2.5-12.1 per 1,000 hours). The injury rate in CrossFit is equivalent to that seen during training periods of triathletes, which reported an average injury rate of 2.5 per 1,000 hours.
We can establish three conclusions from these comparisons … Participating in CrossFit puts individuals at a higher risk of injury than they would be if they never began exercising or participated in only low-impact exercises. It seems to be less than or relatively equivalent, depending upon the source, to running or triathlon training, which are two commonly pursued recreational activities. Finally, it is significantly less than what is observed in contact or team sports.”
The Importance of Proper Movement Techniques
By understanding how to properly brace your spine and learning the correct sequence of movement, you can reduce your risk of most injuries. Proper posture and correct movement also affects your overall health in ways you may never have considered. As Starrett explains in my interview with him, included above for your convenience:
"There's a lot of emphasis on pelvic floor dysfunction in women. But when your spine is in a disorganized position, then you're either overextended or flexed ... What ends up happening is that in the diaphragm, mechanics are compromised. What we see is decreased excursion of the diaphragm and we start to see more patterned breathing up to the neck, which is inefficient...
You cannot stabilize your spine as well [either] because you cannot use your diaphragm to create strong intra-abdominal pressure. So, you end up creating a very dysfunctional, stressed breathing pattern that also impacts your cortisol levels – your stress hormones ... If I can get your spine organized and cultivate that, we clean up breathing problems, we clear up pelvic floor dysfunction, and spine dysfunction. That's number one — we always prioritize spine first in everything we do."
Advice From the Fittest Man on Earth
CrossFit is also becoming known for its annual CrossFit Games. Described by Sharon Alfonsi as “part Olympic Games, part Hunger Games,” CrossFit athletes from around the world compete in a four-day long event to see who’s The Fittest Man, or Woman, on Earth — a title Glassman has actually trademarked. Last year, CNN9 interviewed Rich Froning after he won for the fourth year in a row.
“Picture it: A four-day competition, with two to four workouts a day that consist of running, swimming, muscle-ups, 345-pound squat cleans, handstand push-ups, rope climbs, double unders, handstand walks, 245-pound overhead squats and more, against 43 of the most in-shape competitors you know, all with the title of Fittest on Earth on the line.
Now imagine doing it four years in a row — and winning every time. That's what Rich Froning did as he secured his fourth consecutive title as the Fittest Man on Earth ...”
As for avoiding injuries, “the world’s fittest man” cautions people to start slow when getting into CrossFit training.
“I think people start out too quickly and say things like, ‘Rich does several workouts a day so I can do several workouts a day, too.’ No, you need to ease into it and find a good coach … [T]he best-case scenario is doing it with a good coach and learning the right movements.
For me, doing bodybuilding-type workouts using single-joint movements led to more injuries and more flair ups than I've had doing CrossFit. I had shoulder surgery before I did CrossFit, and my shoulder has never been stronger, so I think it's great.”
Recovery Is an Important Part of the Fitness Equation
While Froning trains up to three hours a day, I would caution you not to follow his lead as recovery is an important part of the equation. Starrett believes competitive athletes can train hard nearly every day as long as they are using different movements, but as a general rule, I would not recommend doing high intensity exercises more than three times per week.
Your body needs to properly recover in between. The key concept here is to train your body gradually, over time, to be able to handle higher intensity workloads. You really need to learn to listen to your body, and not push it too far.
While CrossFit has potential pitfalls, it’s hard to deny it can be incredibly effective. After all, intense interval-type training has repeatedly been shown to be the most effective and efficient way to get fit. A 2013 study10 done by Ohio State University researchers found 10 weeks of CrossFit-based high-intensity power training resulted in significant improvements in VO2 max and body composition in both men and women, regardless of their initial fitness level.
Exercise Wisely for Optimal Health
So, what’s the final word on CrossFit? I believe it can be an effective high-intensity workout, especially if you’re already fit and want to take your workout to the next level. Just make sure the CrossFit gym you use has qualified trainers to monitor your form and teach you the proper mechanics to avoid injury.
To learn more about CrossFit and proper body mechanics, check out the London Real segment on Starrett’s “Supple Leopard” ideology, above. Starrett’s training center also has a website11 where you can find about 800 videos, including "mobility workout's of the day."
Studies have repeatedly shown high intensity interval training (HIIT) is among the most effective ways to improve your fitness and health, as it boosts fat burning, muscle building and cardiovascular fitness while requiring far less time than other forms of exercise.
Naturally, there are many ways to get HIIT into your program — you don’t have to jump into CrossFit right from the start. Greatist12 has summed up several of the HIIT programs available, along with its benefits, in the following infographic. This is the place to start if you want to give HIIT a try.