Let’s be honest, any kind of physical activity carries a risk for injuries, which in some cases could lead to permanent disability. Take the example of these Scandinavian studies that found that sports injuries represent 10 to 19% of all acute injuries seen in an emergency room. 

In sports like soccer, football, basketball and volleyball; the ligaments that help stabilize the knee joint are the most affected, especially in 15–25 year old athletes, where women are 3-5 times more prone to suffer from this injury. Unfortunately, the consequences of sport related injuries go further than athletic performance reaching an increased absence from work and the risk of long term physical damages. No wonder why sports injuries are a big cause of concern for athletes, their relatives and society. 

CrossFit was developed as a core strength and conditioning program. For some, CrossFit is a form of high-intensity interval training. For others CrossFit is a sport of fitness that not only serves as a form of competition but as a form of general exercise training. Either way, CrossFit has the particularity of mixing high-intensity exercises with functional movements making it a very technique-demanding discipline aside from the high physical endurance required. The combination of these factors can look extremely risky for athletes in the early stages of their fitness journey and for the general population.

How risk factors for sports injuries are actually measured?

When studying risk factors for sports injuries, the objective is to first determine that sports injuries constitute a threat to the health of athletes and then establish steps to injury prevention. For that, two factors are considered, the risk factors (why an athlete may be at risk) and how injuries happen (injury mechanisms). There is little agreement among researchers on what causes an injury because there are many risk factors involved as we will see below. There is a need for more studies with proper design and sufficient sample sizes to assert the risks related to a specific sport, including CrossFit. However the following model can give us an idea on how multiple factors interact to produce sport injuries.

The Meeuwisse model divides risk factors into two main categories: internal (or intrinsic) athlete-related risk factors and external (or extrinsic) environmental risk factors. The internal risk factors add to the risk of injury but, by themselves, don’t produce injury. The external factors are enabling factors that facilitate the production of injury.

Internal risk factors:

• Age 
• Gender
• Body composition (body weight, fat mass, BMD, person’s size, form, and functional capacities)
• Health (history of previous injury, joint instability)
• Physical fitness (muscle strength, power, maximal oxygen consumption, joint range of motion (ROM))
• Anatomy
• Skill level (specific technique, postural stability)

External risk factors:

• Human factors (team mates, opponents, judges/referees)
• Protective equipment (belts, shin guards, etc)
• Sports equipment (dumbbells, barbells, etc)
• Environment (weather, floor and turf type, maintenance)

However, only identifying the internal and external risk factors for sports injuries is not enough. We also need to understand the causes and the mechanisms by which they occur. Meeuwisse added to the model what he named the inciting event to sports injuries which are: joint motion (kinematics, joint forces and moments), playing situation (skill performed) and training program.

In CrossFit, the inciting events could be categorized as:

Joint motion: The CrossFit program harvests a multitude of elements from the sports of gymnastics and weightlifting.

Playing situation: CrossFit training consists of different exercises to master various physical tasks (e.g. olympic lifts, rope climbing, traditional sports, moving large loads over long distances)

Training program: exercises are performed either for time or for maximum repetitions and can be conducted as individual, partner or group training. Another format is to complete a specified number of repetitions every minute on the minute, or other timed interval. 

All these inciting events in CrossFit differ depending on the athlete’s individual condition, training location, intensity, duration, organizational form and complexity.

To sum up, injury risks in CrossFit haven’t been deeply studied yet. But, if we take the Meeuwisse model to analyze the risk factors that could lead to injury while doing CrossFit, we can say that the three levels: internal, external and inciting event categories; are all together involved in determining the exposure to injuries. Is the interaction of all those multiple risk factors and events that put a CrossFit athlete at risk of injuries and not only the CrossFit methodology.

What are the most common injuries in CrossFit?

This article found that shoulder joint, shoulder girdle and spine injuries (specially the lumbar region) are predominating in CrossFit and require special attention from physicians and coaches. The authors also concluded that the injury risk in CrossFit is similar to other sports such as Olympic weightlifting, powerlifting and gymnastics, and lower than competitive contact sports such as rugby union and rugby league. 

For female CrossFit athletes, the prevalence of (involuntary) urinary incontinence (UI) is significant. For instance, in a population-based internet study of 551 female CrossFit athletes, 29.95% manifested having UI. Most women with UI reported loss of urine during at least one exercise (16.70%). Double under, single under and box jumps are the most frequently mentioned exercises that lead to UI.

Also, the risk of injuries may be higher among beginners than among experienced CrossFit athletes. 

Pay attention here! In CrossFit previous injuries also increase the risk of re-injury, which is consistent with the model of Meeuwisse and should also be taken into account to prevent long term injuries.

Ok, so CrossFit is as risky as other similar sports, but how efficient is it actually?

The technical answer is exercise efficiency is probably best measured in terms of the total number of calories that you burn. And therefore, the efficiency of exercise in terms of calories burned per unit of time is commonly measured in something called the metabolic equivalent score, or METs. This method helps rank all the exercises that you could imagine doing from the most intensive to the least intensive. The scale starts at one, being one basically at rest. In the sort of standard scales, the activities that are right at the top are running and soccer, which presumably means running all the time, unless you’re the goalkeeper! And then it works its way down. So things like running are a ten, playing basketball is an eight, jogging is a seven, weightlifting is a six, and golf is a four and a half. But it’s interesting because there are also some activities on the list that are things you might have to do anyway like yard work that is a six. The MET level of the workout CINDY ranks as a nine point five, classifying it as “vigorous intensity” based on established American College of Sports Medicine HRmax guidelines. 

Another way of measuring the efficiency of a physical activity is by measuring the intensity in performing it. There are a number of studies that have looked at different forms of high intensity interval training and have found that, for instance. you can do one minute of hard bicycling and one minute of much easier bicycling. And if you do 10 of those intervals you get essentially the same physiological changes within your body as if you do about 90 minutes or two hours even of more common endurance training where you just go riding. And that means simply that you go very, very hard for a brief period of time, then you have a short break, and you go very, very hard again. It seems very clear that these intense bouts of exercise can improve your fitness and also improve your health just as much as much longer bouts. But they have to be hard. They have to hurt.

CrossFit is a form of high-intensity interval training and is comparable to other high-intensity exercises. It increases maximal oxygen consumption, strength, endurance, and improves the body composition (lean body mass). One of the main characteristics of CrossFit is that the exercises are performed quickly and repetitively while there is limited or no recovery time between the sets. So yes! It hurts and burns, but in a healthy way, trust me.

Final Thoughts

You know, there are a lot of questions that we wish sports science would answer. But sometimes they’re either not given enough priority in the scientific community, or the studies that are carried out are done on small populations that the results can’t necessarily be used as significant. So, instead of following misleading information we encourage you to embrace the concept of self-experimentation because at the end of the day, if it works for you, it’s really not that important what works for others. It’s really more important what works for you and your personal fitness journey. 

If you are looking to stay out of sport injuries, go through the internal and external factors we shared in this article to minimize your exposure. In particular, if you are a CrossFit beginner, take foundation programs, aka on-ramp programs, to build your technique before loading weights and talk to your physician about your physical condition and medical background. Train in affiliated gyms who have qualified coaches. And, increase the scope and intensity slowly and carefully following your coach’s advice. Have fun!