A Physiotherapists Two Cents on Crossfit


A Physiotherapists Two Cents on Crossfit

Guided by the saying, “Don’t knock it ‘til you’ve tried it” I set off for my first CrossFit class. From what I could previously gather, CrossFit is a highly motivational exercise class that encourages participation, has fantastic camaraderie and has resulted in an entire community of CrossFit enthusiasts. Don’t let these lean and energized cross fit fanatics intimidate you though!   Everyone was friendly, helpful and obviously had no qualms (nor found any amusement) with the fact that I cannot in any way lift my own body weight. It was fun to try some new exercises and I left feeling great, albeit exhausted with blistery hands (my soft, regularly moisturized Physio hands can only handle so many chin ups).

There is no argument that CrossFit is motivational, thousands of participants Australia wide can provide anecdotal evidence to this. The controversy comes from speculation that participation has a high correlation with injury.

CrossFit is described as “constantly varied functional movements performed at a high intensity” (More comprehensive information can be found at https://www.crossfit.com/what-is-crossfit).

The main workout is usually a sequence of a few exercises performed against the clock. Note some, but not all exercises within this circuit are with weights. When combining speed and maximal effort, you are essentially performing plyometric exercises.  Plyometric exercises involve shortening and lengthening the muscle quickly against resistance. Effectively producing maximal force as quickly as possible to generate power. Plyometrics are the pinnacle of resistance training – it doesn’t get much harder!

High level research has indicated that the appropriate use of plyometric training in your exercise regime can have numerous benefits. This includes, but is not limited to, improvements in sprint, agility and jumping performance. It is thought that these improvements are due to improved neuromuscular function (better neural drive to and quicker activation of your muscles) and increased size of the muscle-tendon complex. Note however that the studies that reported this were all completed on the young and athletic population. Nevertheless, it has also been suggested that although improvements are greater in the already physically active population, plyometric exercises also produce strength, speed and power gains in those with poor physical condition.

Exercise puts your muscles and tendons under stress. In response, they adapt so as to become more efficient at withstanding this specific form of stress in the future. This adaptation occurs when you are resting. If however, you have inadequate rest or the initial stress was too high, the body may start to break down leading to possible musculotendinous injury. Injuries can occur in CrossFit when participants try to progress too quickly. This happens in all forms of exercise, whether you are training for a fun run, recovering post operatively or even upping your yoga game! The same principles apply. You don’t become an athlete overnight (unfortunately).

Interestingly, it has been found that regardless of whether athletes did high intensity, lower limb plyometric exercises twice or four times a week, the end results on sprint and vertical jump height performance were the same.   Contradicting the notion “the more, the better”.   Studies have reported that completing 20 sessions over 10 weeks with a total of 50 squat jumps per session was adequate to produce significant gains.

This is not to say that you shouldn’t exercise more than twice a week, but rather vary the type of exercise you participate in. If you do lower limb exercises on Monday, perhaps do upper limb plyometric exercises and/or low resistance lower limb exercises on Tuesday.

In summary, CrossFit is great! It gets people participating in and actually enjoying exercise. High intensity exercise can produce great physical gains however when implemented poorly can lead to injury.   Exercise should always be prescribed specifically to you. Your training load should be regularly reassessed factoring in how you have previously responded to exercise, your fatigue levels and your increases or decreases in physical performance. More importantly, it is your responsibility to communicate with your trainer on your level of exhaustion and presence of injury. Want some more light reading? Check out the references below.

So, don’t knock it until you’ve tried it! At the end of the day I just want you all to feel good and be lively.   If you love CrossFit great, enjoy! If it’s not for you, find another form of exercise or physical activity that gets you out of bed in the morning.

By Stephanie Vanden-Bergh (Physiotherapist, APAM)



De Villarreal, E., Gonzalez-Badillo, J., Izquierdo, M. (2008). Low and moderate plyometric training frequency produces greater jumping and sprinting gains compared with high frequency. Journal of Strength and Conditioning, 22(3), 715-725.

De Villarreal, E., Kellis, E., Kraemer, W., Izquierdo, M. (2009). Determining variables of plyometric training for improving vertical jump height performance: a meta-analysis. Journal of Strength and Conditioning Research, 23(2), 495-506.

Harries, S., Lubans, D., Callister, R. (2012). Resistance training to improve power and sports performance in adolescent athletes: A systematic review and meta-analysis. Journal of Science and Medicine in Sport, 15(6), 532-540.

Markovic, G., Mikulic, P. (2010). Neuro-musculoskelatal and performance adaptations to lower-extremity plyometric training. Sport Medicine, 40(10), 859-895.

Rosengarten, S., Cook, J., Byrant, A., Cordy, J., Daffy, J. & Docking, S. (2015). Australian football players’ Achilles tendons respond to game loads within 2 days: an ultrasound tissue characterization (UTC) study. British Journal of Sports Medicine, 49(3), 183-187.