CrossFit, the popular fitness methodology that has a bit of almost everything in it, ranging from weight lifting to swimming to rope jumping, has a lot of things going for it. It administers and elevates multi-joint, ‘natural’ movements, gives the whole body some action, fosters multi-faceted physical fitness, and places quite a bit of emphasis on training with good form (there’s no denying that there’s an injury risk to it though). Furthermore, perhaps more importantly, it has a strong social element to it, having proven very effective at bringing people together into tight-knit, vibrant communities. Finally, I’d argue that it makes for great entertainment. In this respect, the incredible feats of the top-level athletes are especially impressive and awe-inspiring. (Personally, I’m particularly taken by the top Icelandic women, who in addition to being completely badass exude passion and warmth). In that sense, CrossFit is tremendous.
That being said, it’s not, as some have claimed, ancestral by nature…
Hunter-gatherer fitness vs. CrossFit
Our primal ancestors were certainly very physically active; however, they would have never engaged in anything closely resembling the ‘typical’ (yes, I know they vary a lot) CrossFit WOD (Workout of the Day). Perhaps the most striking difference between ‘hunter-gatherer fitness’ and CrossFit has to do with intensity. Whereas hunter-gatherers mostly (but certainly not exclusively) engage in low-moderate level aerobic activity, sometimes covering as much as 15-20 kilometers a day, CrossFit is very heavy on high-intensity training. Actually, it’s explicitly stated to be a high-intensity approach to exercise.
The types of activities that are performed also differ. Hunter-gatherers, and in particular the hunters, tend to walk a lot, run quite a bit at a moderate pace, sprint every now and then, and occasionally jump over obstacles, throw stuff, and do some climbing. They’re no strangers to lifting things, frequently having to carry small kids, food, and materials of various kinds around; however, they obviously don’t do heavy deadlifts, military presses, or clean and jerks. Nor do they forcefully maneuver heavy kettlebells around. This is reflected in their physique. Hunter-gatherers tend to pack a bit of muscle; however, they’re by no means jacked. They certainly don’t look like bodybuilders or top-level CrossFitters.
Historically, women have been more stationary than men, typically staying closer to camp, where they care for the young, keep things organized, and collect tubers, berries, and the like. In some respects, this routine differs even more from that of the typical modern CrossFitter, both with respect to its intensity, as well as the types of activities performed.
Finally, it’s important to recognize that the types of activities that hunter-gatherers perform don’t really vary that much, for the simple reason that the things they have to do to survive and reproduce tend to remain fairly constant over time. There’s obviously going to be some variation as to exactly how much effort that’s required to put food on the table and the exact nature and sequence of conducted movements; however, one wouldn’t expect things to change that much from day to day, unless there’s a major seasonal or environmental shift.
The Hadza hunter-gatherers, for example, are in many ways creatures of habit, in that they regularly hunt, dig for tubers, care for the young, collect berries, and go to great lengths to get a hold of honey when that’s available. They don’t suddenly wake up one day and decide to do something completely different the coming week. The Hadza are by no means outliers in this respect. Furthermore, it could be argued that they are particularly relevant to our discussion, as they occupy a part of the world where much of human evolution is thought to have taken place. Hence, their activity pattern undoubtedly bears some resemblance to that of early humans.
CrossFit, on the other hand, emphasis variation. Actually, it may be said that constant variation is one of its distinguishing characteristics. ‘Each’ workout is unique, featuring different exercises and movements, ranging from front squats to kettlebell swings to rowing to handstands. There’s no set rep range, sequence of events, or rest period.
You don’t need plenty of field experience or a PhD to reach these conclusions. All one has to do is consider what we humans historically have had to do to survive and reproduce, and then compare the outcome of that deduction with what we know to be true about CrossFit. So as to make sure one is on firm grounds, it’s arguably wise to also read some of the many interesting scientific papers concerned with ancestral human physical activity patterns that have been published, such as this one, this one, and this one, as well as listen to what people who’ve visited with indigenous people have to say about the way they live; however, even in the absence of such information, one should be able to make a pretty good guess as to what our ancestors did on a daily basis by envisioning what they had to do to put food on the table and otherwise support themselves, as well as by recognizing that they would have been averse to expending energy unnecessarily, not going for a jog just for the fun of it.
Of note, one doesn’t have to go as far as to the Pleistocene to recognize that there’s something fishy about the notion that CrossFit is firmly rooted in the past. A hard-working Neolithic farmer or 19th century industrial worker would certainly have exerted themselves on a daily basis, perhaps regularly lifting heavy things; however, to say that they were basically crossfitters is a big stretch. This is not to say that crosstraining, per se, isn’t an evolutionarily sound form of exercise; however, the claim that the branded fitness concept CrossFit, as it’s currently formulated and prescribed, is ancestral by nature is a bit dodgy.
Why does it matter?
At this point, you may be asking yourself why or if it matters whether CrossFit is representative of ancestral human activity patterns or not. The reason it matters is that our physiological requirements, tolerance, and adaptability with respects to physical activity were shaped over evolutionary time. Any exercise routine that falls outside the boundaries of what we’re biologically suited for is liable to be problematic. This is reflected in the scientific literature.
Exercise-related health implications
On the one hand, it’s well established and widely recognized that a sedentary way of living, which represents the lower extreme of the physical activity spectrum, is a major risk factor for metabolic problems, cardiovascular disease, and certain neurocognitive disorders, to name a few issues. The dangers associated with excessive training aren’t as well-documented or widely recognized, in part because far fewer people are extremely physically active than sedentary; however, they are no less real. Actually, it tends to be even more dangerous to take exercise to the extreme than to be glued to the couch.
Not only does extreme forms of training put one at increased risk of musculoskeletal problems (including exertional rhabdomyolysis, a muscle-breakdown disorder that CrossFit has been accused of causing) and injuries, but it can also undermine one’s health in general by putting excessive strain on organs such as the kidneys and heart. For example, regular, prolonged endurance training performed at a high intensity has been linked with various adverse cardiovascular outcomes (2, 3). As for CrossFit, not that much research specifically concerned with the long-term dangers of extremity has been conducted; however, there’s no reason to think that it differs from other forms of training in this respect.
When correctly applied and executed, CrossFit doesn’t necessarily carry a higher injury risk than other forms of exercise. It may even help prevent musculoskeletal pains and deterioration. That said, there’s no denying that repeated, intense execution of complex exercises poses a risk for many. This is reflected in the literature, including in a 2014 study which found that about 20% of the surveyed population had been injured as a result of CrossFit training (1).
As for more general effects, it’s important to recognize that exercise can have both good and bad effects on the immune system, depending on its intensity, duration, and frequency. In moderation, exercise is recognized as being anti-inflammatory; however, when it exceeds the body’s tolerance, it’s effects are much less pleasurable. This idea is accentuated by studies linking high-intensity exercise, including CrossFit, with inflammation and oxidative stress (4, 5, 6, 7). If adequate rest is provided, homeostasis is restored, but if it’s not, chronic, inflammation-related issues may arise.
Diet-related health implications
Another important issue is that people who are extremely physically active have supernormal energy requirements. I should know, as I used to be one of these people. By nature, extreme training goes hand in hand with extreme eating, which is going to have adverse health effects, not only because it puts pressure on the gastrointestinal apparatus, but because it’s almost impossible to eat perfectly healthy when one’s nutritional requirements are significantly elevated above normal levels.
This brings up another issue, which is that CrossFit’s close association with the Paleo diet is, to some extent, unjustified and may have undermined, rather than enhanced, some people’s perception of the diet’s workability. I’m a big fan of Paleolithic nutrition. That said, I’m not convinced that crossfitters are best of strictly adhering to the principles of that ancient nutritional regimen, for the simple reason that they do so much high-intensity work. Those who only do CrossFit for the fun of it, in moderation one or a few times per week, may do well on the diet: however, hard-training crossfitters may need to make certain adjustments in order to perform optimally.
By itself, the fact that preagricultural human diets were generally quite low in carbohydrates adds support to the idea that our primal forebears didn’t regularly engage in prolonged high-intensity exercise, as emphasized by this quote:
From an exercise perspective, maintenance of prolonged, intense exercise (i.e. above the lactate threshold) could not be expected in those ancient times, as glycogen availability would have been limited, resulting in greater reliance on fat metabolism. (8)
The bottom line
To the habitual crossfitter who eased into the whole thing, is relatively healthy, takes plenty of rest days, and performs exercises with good form; the aforementioned things aren’t that big of an issue; however, to those who don’t fit all of these criteria, they may very well be. In particular immunocompromised individuals and people whose backs and legs bend in all sorts of weird ways as they’re working out may want to take pause and consider if what they’re doing is causing more harm than good. This goes for exercise in general though, not just for CrossFit.
Part of the reason why I’m so focused on this issue is that I’ve previously made the mistake of putting too much physical strain on my body, thereby compromising my health and well-being. In the aftermath of that mistake, I became more conscious of the dark side of fitness. These days, the question I usually ask myself when assessing the merits of a fitness routine is: Does this type of routine suit our evolved biology?
The popular fitness concept CrossFit has several favorable attributes, including its focus on functionality, execution, community, and performance. However, a comparison with ancestral human activity patterns reveals that it does not live up to its reputation of being firmly grounded in our evolutionary past. Our hunter-gatherer ancestors were very physically active, conducting a variety of tasks as part of their daily ‘struggle’ to survive and reproduce; however, they didn’t engage in high-levels of constantly varied high-intensity activity: a prominent hallmark of the modern CrossFit enterprise. This is reflected in traditional societies, where walking and digging, not deadlifting or push pressing, are dominant forms of activity, as well as by the non-bulky hunter-gatherer physique and their low-carbohydrate diet. This is not to say that CrossFit is all bad or that crosstraining in general isn’t an evolutionarily sound form of training; however, it suggests we’d be wise to show caution, as any physical activity pattern that deviates substantially from the evolutionary norm for our species is liable to be problematic.