CrossFit: An Independent Unbiased Review


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CrossFit exploded onto the scene about a decade ago and since then has amassed a huge following – and a lot of criticism.

But is this criticism fair and warranted?

CrossFit helps a lot of people, so how can it be bad?

In this guest post by professional strength and conditioning coach Dan Jolley, PhD, he takes a step back and provides a level-headed and balanced rundown on CrossFit, the pros and cons, and those who might benefit most from it.

Over to you Dr Dan!  -Bill

There has been a massive change in gyms and group exercise over the last few years.

At the forefront of this has been one of the most polarising exercise modalities of recent years – CrossFit.

While nothing in a CrossFit workout is actually new (they use bars, weights, and equipment that has been around for decades), their workouts are put together in a novel – and in some circles, controversial – way.

Plenty has been written about CrossFit, most of it very polarising.

Therefore, the aim of this article is to take the view of an impartial observer.

I’ll assess the pros and cons of this form of exercise and examine what the evidence says about its claims.

Principles of CrossFit

To define CrossFit, it is useful to go to the source. According to the CrossFit website:

CrossFit is constantly varied functional movements performed at high intensity. All CrossFit workouts are based on functional movements, and these movements reflect the best aspects of gymnastics, weightlifting, running, rowing and more.

While this isn’t necessarily a novel approach, there are a couple of things worth noting. One is the use of the word “functional.”

What Does “Functional” Actually Mean?

“Functional” is a buzzword bandied about by the fitness industry in recent years and tends to be attached to the use of free weights, body weight exercises, and exercises that challenge stability. None of these are bad things.

In fact, as a strength & conditioning coach, these are all options I use daily.

You will always see plenty of free weights in a CrossFit gym, and this has influenced the broader fitness industry to provide this equipment too.

But when deciding whether or not a movement is functional, it’s worth considering whether that “function” is relevant to the person doing the training.

Personal trainers are generally taught to select exercises (and other variables) to suit the needs of the client.

This is good practice regardless of whether or not you consider your exercise “functional”.

There isn’t necessarily an agreed-upon industry standard definition of this term as it relates to exercise.

The key phrase from the Wikipedia definition, “movements based on real-world situational biomechanics” is a good place to start.

CrossFit has a slightly different take:

We scale load and intensity; we don’t change the program. The needs of Olympic athletes and our grandparents differ by degree, not kind.

What this suggests is that everyone walking into a CrossFit gym will do the same workout, in the same order, though the resistance applied will vary.

Exercise selection is generally seen as a fundamental part of exercise prescription that can be varied to suit the individual (a good summary of the research on resistance training prescription can be found here).

CrossFit suggests that everyone can benefit from the same program.

To a point this is true: beginners, especially, will benefit from any increase in exercise levels, regardless of the choice of movement.

This becomes less true with more training experience since the athlete is closer to his/her own physiological ceiling, but more on that later.

CrossFit and Exercise Intensity

The other variable that may be manipulated in a CrossFit workout is intensity:

The more work you do in less time, or the higher the power output, the more intense the effort. By employing a constantly varied approach to training, functional movements and intensity lead to dramatic gains in fitness.

In this case, the concept of power (i.e. a faster workout) is used synonymously with intensity.

But in other modes of exercise, intensity can be changed in other ways.

In resistance training, for example, intensity is often measured as a proportion of the maximal weight a person can lift (i.e. their one repetition maximum, or 1RM) that is used for an exercise.

When running, intensity could be the proportion of maximal speed or heart rate, depending on what can be measured at the time.

Further, if we look at intensity subjectively, a more intense effort could be anything that the exerciser thinks is harder (the concept of RPE – rate of perceived exertion).

This can be influenced not only by the difficulty of the workout, but other social and psychological factors, and their recovery from their previous workout.

We can also vary difficulty of a workout by using methods such as repetitions which are slower, or over a longer range of motion, or more repetitions at a lighter weight.

The speed of the movement is just one variable that a good trainer can manipulate.

In CrossFit however, the emphasis is on completing workouts faster.

Speed is characteristic of these workouts, rather than a variable to adjust.

How Can You Tell Which is a CrossFit Gym?

This can be harder than you think. CrossFit gyms are independently owned, not franchised.

As such, there is no common image or corporate branding. And while there are similarities in the types of equipment you will find, the size and layout of gyms will vary significantly.

Similarly, they tend to be operated by the owners, and there can be significant differences in the approach of the owners and the instructors they employ.

They have a few things in common though.

The word “CrossFit” will probably be in the title. When you go into a CrossFit gym you know what you are going to get in terms of exercise.

You will lift weights. The exercises will generally be big, compound (multiple joint, multiple muscle group) lifts. You will be challenged to lift heavy.

There will be an element of cardiovascular fitness in the workout.

And you will race against a clock, with your time being written up on a board.

Each gym will have their “workout of the day” or WOD.

In keeping with the principles of CrossFit, most people who attend the gym that day will complete this session.

Depending on the gym they may have other classes or sessions for different levels of ability.

The workout may take around 45 minutes, so fits pretty comfortably into a working day.

One of the major characteristics of CrossFit is the atmosphere of the gym.

Though (as mentioned earlier) there is significant variation in gyms, there is an element of teamwork and camaraderie that is missing from most commercial gyms.

You don’t see many people training on their own in a corner wearing headphones.

This is either a positive or a negative – depending on how you like to train – but it is obvious!

There is a genuine social element to attending one of these gyms.

Who Are CrossFit Coaches?

Again, this is a tough one to answer, as the coaches I’ve met come from a variety of backgrounds.

Some have come from a traditional gym or personal training background, some have sport science degrees, and others have come from sporting or Olympic weightlifting backgrounds.

And some have known nothing but CrossFit in their fitness careers.


CrossFit qualifications have been a point of discussion in the fitness industry for some time.

The basic qualification for a new instructor is a two-day course, which includes theory, practical components, and an assessment.

There are other courses an instructor can do to update their knowledge after that but these are not compulsory.

While this is better than nothing, it compares poorly to the rest of the industry.

In Australia, the Certificate III and IV qualifications for personal trainers, for example, have recently become much more demanding and can take up to 12 months to complete full time.

University qualified personal trainers and accredited exercise physiologists have 3 to 4 years of education.

And to work in sport in a professional or semi-professional capacity as a strength and conditioning coach, it’s pretty hard to even get a foot in the door without a Master’s degree or PhD, as well as practical coaching qualifications.

While not everyone needs such a highly qualified coach, it is clear that, in terms of education and depth of scientific understanding, basic CrossFit certifications compare poorly to the industry at large.

It’s always useful for the client to know what qualifications their trainer holds and whether they are up to date with ongoing education.

Is CrossFit Effective?

The short answer is: it depends on the individual and level of exercise experience.

One of the key tenets of CrossFit – the high effort the workouts consistently call for – means that even someone with a decent exercise history can stand to benefit from the increased effort.

All of us have been guilty of coasting in our workouts from time to time, so getting pushed harder can lead to real improvement.

The workouts are also conducted in group settings, against the clock, with the encouragement of trainers.

The psychological benefits of this environment are huge; most of us will work harder in these conditions.

If you have fairly general fitness needs, this could be a great environment for you.

For those with more specific needs, CrossFit might not be their best option.

Earlier in this article, I discussed the need for specificity when designing training programs.

For those with a long training history, or those who compete at higher levels of sport, generic programs are comparatively less effective.

For example, in my time as a strength and conditioning coach, I have worked at high levels within Australian Football and American Football (gridiron).

Both groups of athletes need a degree of aerobic fitness and repeat sprint ability. CrossFit would improve both groups of athletes if they were relatively untrained.

But the Australian Football players may need to run hard over relatively long distances with short rest between efforts.

The American Football athletes, on the other hand, need to be able to perform high intensity sprints, but get much longer recovery between efforts and cover much shorter distances.

I spend much more time developing the aerobic capacity of Australian Football players, whereas the gridiron guys have much more of a repeat sprint focus.

With CrossFit’s focus on generic programming and timed workouts, and speed as their major marker of intensity, the specific requirements of each sport may not be met.

Additionally, differences in the distances covered, types of change of direction and physical contact, and the different body positions in the sports mean the training programs of these players end up looking quite different.

And lastly, the needs of an individual may change over the course of a season.

Meeting these needs often involves an element of foresight and planning (called “periodisation”).

The WOD on any given day may not match these needs.

How Safe Is CrossFit

The answer to this is, it depends who you are (do you sense a trend here?). It is hard to label CrossFit as “safe” or “unsafe” due to the massive variation in gyms and clientele.

But regardless of the gym you are joining or the exercise program you are beginning, there are a few things that should be standard:

  • Did the gym you joined ask you to complete a form outlining your medical and injury history?
  • Did they ask follow up questions based on the answers you provided?
  • If they identified you as a high risk client, did they request a medical clearance?

If they didn’t do any of these things, they are breaching their duty of care.

There is now an industry standard form and process endorsed by both Fitness Australia (which regulates personal trainers), and Exercise & Sports Science Australia (which regulates exercise physiologists).

This level of detail is a good start and clearly a step in the right direction.

  • Did the trainers at this gym assess your ability to perform the exercises required? A movement screening of some sort (for example, the Functional Movement Screening), a fitness test, or a strength test, would provide relevant information here. If everyone is doing the same program, it’s worth making sure everyone is capable!
  • Do they offer introductory courses? Despite the marketing, I know from firsthand experience that not everyone can do the same movements. In particular, CrossFit WODs may involves parts of (or even full) Olympic lifts, which are technically quite challenging. If they run beginner’s classes, sessions where they teach these lifts, or individually adjust the exercises to suit the individual participant’s ability, you can have some confidence that they are looking after their members.

There is an inherent risk to performing any exercise under high levels of fatigue, such as CrossFit may encourage.

As a general rule, injury rates in CrossFit are comparable to other sports.

A 2014 study of CrossFit participants found the injury rate to be 20%, though those with more trainer supervision had lower injury rates.

This may be a level of risk that someone wishing to compete in CrossFit may be willing to take on, but the recreational exerciser with general goals should make an informed decision about whether this exercise intensity (and risk) is appropriate for them.

CrossFit-induced Rhabdomyolysis?

One of the most well-publicised risks of participating in CrossFit is rhabdomyolysis (or “rhabdo”).

While this condition is not unique to CrossFit, there has been an upsurge in rhabdo cases with the increasing popularity of this type of exercise.

The CrossFit brand is also not helped by the casual way that rhabdo is treated by some of its proponents.

crossfit rhabdomyolysis
“Uncle Rhabdo,” one of the unofficial mascots of CrossFit. Credit:

In an exercise setting, rhabdomyolysis occurs when skeletal muscle breaks down rapidly.

While some muscle damage is an essential part of our adaptation to exercise, a very high volume of demanding resistance exercise using large muscle groups (i.e. squats), can cause an extreme amount of muscle damage.

As a result, byproducts of muscle breakdown enter the bloodstream.

Very dark urine, and unusual swelling in the muscles are obvious signs.

Previously this was seen in athlete populations such as triathletes and ultramarathon runners, but those who are relatively untrained and doing CrossFit workouts have a higher risk than other modes of exercise.

The incidence of rhabdo in CrossFit is not well documented and the scientific literature to date mostly deals in case studies, so it’s hard to draw conclusion from such a small sample of cases.

On top of that, a competent and well-qualified trainer should be able to manage the progression of the client at a safe rate (as discussed above), rather than throwing them off the deep end straight into the full workout.

My Experience?

The aim of this article was to remain impartial and present the risks and benefits of CrossFit to someone without a pre-existing opinion, or a lot of exercise knowledge.

My own personal experience with CrossFit has been fairly limited, but unusual for someone writing an article about this mode of exercise, I am neither an advocate or a hater.

I have used CrossFit gyms for testing and training sessions when coaching teams which didn’t have access to gym facilities.

This is because they have the weights, lifting platforms, and other equipment we need that not all gyms have.

The trainers I’ve met as a result and been welcoming and helpful.

When holidaying in the US a couple of years ago, I was staying with some friends in Denver who train at a CrossFit gym.

I went along for a workout with them one morning and found it to be a reasonably enjoyable experience.

While it was not a session I would normally select for myself, I was happy to join in.

The instructors were degree qualified, did a movement screening with me before the session, and made sure I warmed up properly.

And I got a decent workout (I didn’t perform at my best though – I blame the altitude!). Overall, it was a professionally run operation.

I’m aware of other CrossFit trainers who are highly experienced and possess good qualifications beyond their CrossFit certifications.

Unfortunately, I am also aware of trainers who cut a lot of corners and operate outside their scope of practice (by purporting to be able to treat injuries or prescribe diet plans).

I’m also personally aware of one case of exercise-induced rhabdomyolysis from a CrossFit workout here in Perth.

This person was the typical higher risk candidate for the condition (having a poor training history to that point), but was put straight into the main workout by her trainer and ended up hospitalised.

Take Home Message on CrossFit

Like all exercise modalities, this CrossFit is not for everyone.

If you want a challenge, have a moderate level of fitness, and have lifted weights in the past, go for it.

If you want to compete in the sport of CrossFit, by all means go for it.

If you have a history of injuries or medical conditions that may affect your ability to exercise, then a group setting, or high intensity exercise, may not be the best choice for you. CrossFit is both of these!

If you have very specific needs (such as sports performance), then CrossFit may give you a bit of a boost to your training in the short term, but a more structured long term approach will provide a better benefit.

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13 thoughts on “CrossFit: An Independent Unbiased Review”

  1. Bradney A. Boli

    So many wrong perspectives and understandings in this article but I honestly think that Dan tried but simply doesn’t understand due to an inadequate or incorrect exposure to CF. I would love to spend some time explaining and demonstrating the differences to him because this high level of lack of understanding seems to persist even in educated individuals. I’ve been reading similar misunderstandings of CF for ten years now.

    1. Hi Brad, thanks for reading. Feel free to spend the time explaining here, and if I’ve made any factual errors I’m sure we can have the article corrected.

  2. Bradney A. Boli

    Thanks Dan, I only just today found out that you had responded to my post.

    Regarding the same program for everyone, this is the baseline philosophy however we will scale load, reps, rounds, distance etc. to accommodate the individuals capabilities and limitations. Programming rounds of a 400m run for my 74 yo. mother is absurd however having her run or fast walk for an equivalent amount of time is valuable and effective. The need to pick things up, carry them, manipulate ones body in space in a diversity of ways, to simply squat, is very universal.

    Intensity is another commonly misunderstood concept. Let’s leave alone the issues of physical vs. psychological limits and simply talk about what is intensity. A problem that plagues many areas of society as well as the fitness realm is a lack of definitions for important concepts. We Define intensity as average power output, which IS (force times distance)/ time. Once one gets their head around this concept then the common misperception that all CrossFit is about lifting heavy can finally be put aside. Unfortunately there are plenty within the CF world that don’t truly understand this concept.

    As for the qualifications of the trainers I would argue that the hands on approach that is utilized by CF is much more effective and relevant in the real world of coaching than is a ton of book work. I know very few trainers outside of CF and USA Weightlifting certifications that actually know how to teach proper movements or correct form effectively. Don’t get me wrong, I know plenty of trainers with numerous CF certifications that suck at coaching and I know some with no certificates at all that I would rather coach my classes. It’s just that the hands on approach that CF employs, in my opinion, results in a much more effective and safe coach.

    Finally the rhabdo thing. Uncle Rhabdo as well as Uncle Pukie are intended to be absurd and offensive to those outside of CF. It’s a slap against those who panic and are sure we are all going to die from this crazy, dangerous program. The rest of us understand the reality and fact that the risks are nowhere near what outsiders think. I have been closely involved in a number of significant injuries due to fitness persuits both in and out of CF. Including at least six occurances of Rhabdo. Generally the ones at greatest risk are not the untrained, rather it’s the more highly trained who do something “stupid.” The areas within my experience in CF that actually cause the most frequent (as well as generally most serious) injuries are plyo box jumps and sprinting.

    If you are ever on this side of the planet and want to nerd out feel free to call. I’ll even buy the beers.

    Bradney A. Boli
    Mutiny CrossFit

    1. Thanks for elaborating Brad. It looks like you’ve agreed with most of the points I’ve made in the article! For example:

      1) I identified that exercise selection is often not varied between clients in a given session – you’ve confirmed that.

      2) I identified that power or speed is often synonymous with intensity in CrossFit programming – you’ve confirmed that.

      3) I identified that rhabdo is not unique to CrossFit, and identified some high risk groups and activities. You’ve confirmed this, though your experience is slightly different to the scientific literature (which is understandable).

      I draw no conclusions regarding qualifications, other than the fact that CrossFit qualifications are much shorter than other alternatives. Your response was to compare hands-on CrossFit instruction to a qualification heavy on theory. I agree that hands-on experience is highly valuable, but your argument in this case is a false dichotomy.

      To explain: I teach a personal training qualification that lasts for a full academic year, and involves hundreds of hours of hands-on coaching, as well as theoretical learning. A sports science degree will be similar in the combination of theory and practice. A good qualification will not make you choose one or the other!

      Keep in mind that this article was not a criticism of CrossFit, just an exploration of this type of exercise compared to other forms of exercise, and some suggestions on who it may (or may not) be appropriate for. I’ve been careful to make it clear when I’ve expressed a personal opinion, rather than a fact.

      If I’ve made any factual errors please let me know, but you haven’t identified any so far.

      1. Well weighted response.

        Hands on weight lifting experience lingers dangerously close to Bro-science. I prefer to take my fitness advice from someone educated in whats going on under the skin, rather than what a lift looks like from the outside.

  3. Jake Nickel White

    This is a great article for anyone considering crossfit.

    It came off as unbiased and insightful. I just graduated with a B.S. in Kinesiology and am trying crossfit out to make my own opinion.

    Dan is certainly qualified in education and experience.

  4. Awesome article! It seems like Dan presented information as factually as possible. I appreciate that he also wrote of his own personal experiences which could affect his bias either way so the reader is aware. I just recently joined a crossfit gym and this article makes me feel as though I am going into this venture a little more knowledgeable. Thank you!

  5. Thank you for this informative and well written review. I really appreciated your scientific approach, as a scientist myself 🙂 I also just joined a CF gym and am enjoying the new challenge, but have a few reservations about some things… I think being a healthy skeptic is probably good though! Thanks so much for the great read.

  6. hi dan.
    I’m a doctor and crossfitter in perth. If you’d like to try another session contact me. I’m a fan. I’ve been running and doing traditional gym weights for 20 years before starting crossfit and thought i had pretty much got as good as i can get. Now aged 41 i’m hands down the fittest of my life and made a bunch of great friends too. I think a lot of the bad press about crossfit come from people who have read about it but not actually done it and/or not read any of the peer reviewed studies on it.
    I know the owners of 2 perth crossfit gyms. Give it another go

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