Would you be willing to expand on your thoughts on this article?
I read the article and did some quick Wiki-checking into Rhabdomyolysis.
6 occurences per 100,000 people. (according to the article you linked)
What is the rate of occurence for heart attack during exercise? Or stroke? Serious infections or illnessed picked up at the gym? Or a traffic accident on the way to the gym?
It sounds to me a bit like fear-mongering.
Exercising yourself (literally) to death is a possibility even for a fit person, but my original inclination to this article is that certain people are predisposed to be adversely effected by the intense training associated with Crossfit, and that may lead to rhabdomyolysis.
How is that any different than any other predisposition and it’s implications on which activities an individual should be cautious of, or avoid altogether?
I read the article and did some quick Wiki-checking into Rhabdomyolysis. 6 occurences per 100,000 people. (according to the article you linked)
It is 6 occurences per 100000 people in base population, but much higher among people who do CrossFit. That was exactly the point of the article:
And here we have arrived at CrossFit’s dirty little secret. The coach was unusually familiar with what is normally a very rarely seen disorder. It’s so rare that one study reported the overall annual incidence of rhabdomyolysis to be 0.06%. (...) How, I wondered, is it possible that the layperson exercise instructor is on a first-name basis with a serious, yet rare medical condition? Is this a thing with CrossFit? It turns out it is.
It is 6 occurences per 100000 people in base population, but much higher among people who do CrossFit. That was exactly the point of the article:
The claim that rhabdomyolsis is more frequent in CrossFitters is the question you and Nancy appear to be begging. We have nothing other than anecdotal evidence to support that.
I think it is rather self evident that injuries that result from over-exertion will tend to result at a higher frequency during activities with high levels of exertion.
The criticism seems to be from people who are unfamiliar with the pursuit of high level athletic goals. Injury is a possibility when you set out to reach unprecedented heights of physical fitness. If you want to burn some calories and avoid any potential problems, walk the dog. If you want to accomplish what these Crossfitters do, then there are risks.
Edit to add: I should say that I actually agree with Nancy’s original point that we should “evaluate our competitions carefully”. I think you should decide what you are trying to achieve and consider the risks inherent in that pursuit. CrossFit is only an example of one kind of relatively extreme training. It is trying to approach the limits of what is physically possible, and that involves risk.
We have nothing other than anecdotal evidence to support that.
For extremely rare events, even anecdotal evidence can be pretty good. If you were told something happened to 1 in a billion people, and you met 3 such people, you’d have pretty good evidence that something odd is going on (the rate is a lie, you’re mistaken about meeting them, or something unusual is concentrating them in your presence). Rhabdo isn’t nearly that rare, but it’s pretty rare. That rareness, and a very reliable base rate for rhabdo in the overall population, means that the anecdotes actually get us a lot further than you might expect. I will demonstrate with some Fermi estimates and a little bit of statistical reasoning:
In 1995, hospitals in the U.S. reported 26,000 cases of rhabdomyolysis.
262m people in the USA in 1995, so the base rate is: 26000 / 262764948
Alright, so that’s the base rate for the general population. Now we need a rate for CrossFitters, number of CF rhabdo cases divided by number of people doing CF:
How many anecdotes are we dealing with? I took Nancy’s Medium link, followed each link in it (ignoring any other links in this LW thread), and tallied how many specific, concrete, anecdotal cases of rhabdo were reported in each; sorted by date:
These all sound reasonably exclusive (the 2011 CF paper is specifically about a different time period than the cumulative-to-2005 CF estimate of 6, the comments all seem to be by different people, etc), so we can sum to get 5+2+1+1+4+1+1=15 anecdotal cases of CF. You can argue that some of this is double-counting that I just didn’t notice, but if I looked at a few more threads I could probably add some more aneccdotes, so let’s just call it even.
How many CFers?
Crossfit was founded in 2000; there are now 6100 affiliated gyms. The 2013 CrossFit Games Open apparently had 138k registrations; this was a sort of virtual online competition, it seems, so it seems like a reasonable proxy for total Crossfit participants. Let’s say half didn’t bother to register, so in 2013, there were really more like 300k CrossFit people. That makes 50 CrossFitters per affiliate, which given the high cost of CrossFit and intensive time-demanding training sounds pretty reasonable. How many CrossFit people have there ever been? Making the completely arbitrary assumption that the average CFer lasts one year and assuming linear growth from 1 person in 2000 to 300k in 2013, then there’s been 150k * 13 = 1950000 CFers.
hence, just from these anecdotes, we might estimate a lower bound on the rate of 15/1950000
As it happens, (15 / 1950000) < (26000 / 262764948). To get the CF rate just barely above the base rate, I’d have to increase the number of CF rhabdo cases to 193, since (193 / 1950000) > (26000 / 262764948).
So if you believe the null hypothesis that CFers suffer rhabdo at the exact same rate as the general population, then according to this set of numbers, I apparently managed to get 8% (15/193) of the way to the entire population of CF rhabdo cases just by reading 7 links. As much as I admire my own reading and link-clicking skills, I don’t find that very plausible.
Now, with this set of numbers, how many cases of CF rhabdo would we need before we had something statistically-significant? We’d need another 206 cases of rhabdo to hit p<0.05:
R> binom.test(c(221, 1950000), p=(26000 / 262764948))
Exact binomial test
data: c(221, 1950000)
number of successes = 221, number of trials = 1950221, p-value = 0.04758
alternative hypothesis: true probability of success is not equal to 9.895e-05
95% confidence interval:
9.887e-05 1.293e-04
So our little handful of anecdotes gets us 7% of the way to the claimed conclusion. For the much-maligned anecdote, this seems pretty impressive, IMO.
CrossFit is not that unique. It is just a type of working out hard.
I’m quite confident injuries result more frequently among those who work out hard.
I’ll concede rhabdo is more common among CrossFitters than the general population. The point I should have focused (exclusively) on is that that is exactly what we should expect.
We see lots of concussions in football; lots of tennis elbow among tennis players; shoulder issues with powerlifters; knee problems in runners, etc.
The article seems to me to be fear mongering. It is the nature of highly competitive pursuits that they involve injuries.
More rhabdo among CrossFitters is like saying there are more drowning deaths among those who go swimming.
Meanwhile, the risks involved in living a sedentary lifestyle abound.
Sure, but once you’ve conceded that yes, CrossFit has an unusual increased risk of a disorder both deadly and detrimental to fitness, then you need to deal with objections that CFers would be better off with the next alternative: CF can’t be the only type of working out hard, even if it prides itself on being the hardest work out around.
More rhabdo among CrossFitters is like saying there are more drowning deaths among those who go swimming.
Modus ponens, modus tollens. That may just be a reason to avoid swimming as one’s recreation unless one prefers it so much compared to the alternatives. ‘Drowning’ and ‘rhabo’ seem much worse than ‘shoulder issues’ or ‘knee problems’.
Conceding there are risks inherent to CrossFit (or anything) is a good reason to consider alternatives. Then, you’ll see the alternatives have risks, too.
Then, you may personally decide to partake in any activities for which you are willing to accept the risks.
And again, CrossFit isn’t a magical, dangerous thing. CrossFit = a branded mix of strength/speed/endurance exercises. You can do it reasonably, or over-do it.
CrossFit has an unusual increased risk of a disorder both deadly and detrimental to fitness
The article presented no data other than some evidence about meme propagation in the Crossfit community.
Rhabdo is a consequence of severely overexerting your muscles and is not specific to the types of exercise that Crossfit does. It is specific to motivation and the claim is that, basically, Crossfit overmotivates the newbies. Well, maybe. And maybe other fitness programs do, too. Without data it’s really hard to tell and so far I haven’t seen any.
Sure, but once you’ve conceded that yes, CrossFit has an unusual increased risk of a disorder both deadly and detrimental to fitness, then you need to deal with objections that CFers would be better off with the next alternative
This is news to me and of relevance to my exercise choices. Is it the consensus of all the people on lesswrong who have the name ‘gwern’ that following CrossFit’s workout of the day routine is on net detrimental and to be avoided in favour of something else?
Haha no way. I hadn’t even heard of rhabdo or CrossFit before I noticed this thread. I just read the article and realized it was a great showpiece for one of the rare circumstances where anecdotes can actually be informative.
Haha no way. I hadn’t even heard of rhabdo and CrossFit before I noticed this thread. I just read the article and realized it was a great showpiece for one of the rare circumstances where anecdotes can actually be informative.
Thankyou for explaining. Your reputation as an independent researcher is such that if you had researched the subject I’d just take your word for it. The expected value of information would have to be damn high before it would be worth looking into it myself to confirm. And even then my first thought would be “Value of information is high? Hire gwern at his going rate to do a more thorough analysis.”
From my experience (anecdotal observation) is that with Crossfit what the participant brings into it largely determines what they take out of it. Now perhaps not all Crossfit boxes(gyms) share the same culture. But where I go there is a focus on form and scaling of workouts. Also those that are serious about progressing know how to hold back because rhabdo would destroy their(my) work and gains. Those who have no real goal except some loose idea of improved fitness and health never seem to push themselves hard enough to do damage. I’d say rhabdo would take a unique kind of desire to win over the pain to achieve.
Just to brag and promote: after a year of CF I’ve gained 6kg~ of muscle mass from 78kg to 84kg at 185cm. Crossfit is a tool to achieve fitness goals it doesn’t provide the goals or the motivation just the means exercise both.
I believe that people have some built-in warnings to keep them from hurting themselves, and it’s a cultural pathology to make ignoring those warnings into a virtue. It’s one thing to push through pain in an emergency or to increase your capacities, but it’s another to keep hurting yourself just to prove that you can.
Here’s an example of a workout by Scott Sonnon, who encourages athletic ambition while making serious efforts to keep people from getting injured. This is a free workout he’s offering because people need free, useful things when the federal government is semi-shut down.
I generally agree with your sentiments. There is, however, a relatively tricky balance to achieve when attempting to optimize athletic performance.
I think overtraining has become a bit of an epidemic among novice strength trainers, and “less is more” can be a helpful lesson to learn sooner than later… but extreme athletic results often involve extreme training methods. Injury is a line that is always (very) detrimental to cross, but not pushing yourself close to that line can result in you failing to reach full potential.
You could argue that optimizing for some athletic output is not a wise use of resources anyway, especially given the risks (and I might agree with you) But it just may take the most extreme training to produce the most extreme (and optimized) results.
Would you be willing to expand on your thoughts on this article?
I read the article and did some quick Wiki-checking into Rhabdomyolysis.
6 occurences per 100,000 people. (according to the article you linked)
What is the rate of occurence for heart attack during exercise? Or stroke? Serious infections or illnessed picked up at the gym? Or a traffic accident on the way to the gym?
It sounds to me a bit like fear-mongering.
Exercising yourself (literally) to death is a possibility even for a fit person, but my original inclination to this article is that certain people are predisposed to be adversely effected by the intense training associated with Crossfit, and that may lead to rhabdomyolysis.
How is that any different than any other predisposition and it’s implications on which activities an individual should be cautious of, or avoid altogether?
It is 6 occurences per 100000 people in base population, but much higher among people who do CrossFit. That was exactly the point of the article:
The claim that rhabdomyolsis is more frequent in CrossFitters is the question you and Nancy appear to be begging. We have nothing other than anecdotal evidence to support that.
I think it is rather self evident that injuries that result from over-exertion will tend to result at a higher frequency during activities with high levels of exertion.
The criticism seems to be from people who are unfamiliar with the pursuit of high level athletic goals. Injury is a possibility when you set out to reach unprecedented heights of physical fitness. If you want to burn some calories and avoid any potential problems, walk the dog. If you want to accomplish what these Crossfitters do, then there are risks.
Edit to add: I should say that I actually agree with Nancy’s original point that we should “evaluate our competitions carefully”. I think you should decide what you are trying to achieve and consider the risks inherent in that pursuit. CrossFit is only an example of one kind of relatively extreme training. It is trying to approach the limits of what is physically possible, and that involves risk.
For extremely rare events, even anecdotal evidence can be pretty good. If you were told something happened to 1 in a billion people, and you met 3 such people, you’d have pretty good evidence that something odd is going on (the rate is a lie, you’re mistaken about meeting them, or something unusual is concentrating them in your presence). Rhabdo isn’t nearly that rare, but it’s pretty rare. That rareness, and a very reliable base rate for rhabdo in the overall population, means that the anecdotes actually get us a lot further than you might expect. I will demonstrate with some Fermi estimates and a little bit of statistical reasoning:
Wikipedia says:
262m people in the USA in 1995, so the base rate is: 26000 / 262764948
Alright, so that’s the base rate for the general population. Now we need a rate for CrossFitters, number of CF rhabdo cases divided by number of people doing CF:
How many anecdotes are we dealing with? I took Nancy’s Medium link, followed each link in it (ignoring any other links in this LW thread), and tallied how many specific, concrete, anecdotal cases of rhabdo were reported in each; sorted by date:
http://www.nytimes.com/2005/12/22/fashion/thursdaystyles/22Fitness.html?pagewanted=all&_r=0 Dec 2005 : 1 (“Brian Anderson”), 6 (“as many as six”), assume double-count of Anderson to be conservative: 5
http://library.crossfit.com/free/pdf/CFJ_Wright_Rhabdo.pdf June 2011 : “In recent months, there have been a few incidents of rhabdomyolysis in our affiliates”; ‘a few’ must be at least 2
http://www.menshealth.com/fitness/cult-crossfit/page/4 October 2011 : 1 (Makimba Mimms)
http://www.crossfitsantacruz.com/crossfit_santa_cruz/my-rhabdomyolysis-story.html December 2011 : 1
http://www.crossfitreality.com/?p=381 August 2012 : 4 (author, 3 commenters)
https://medium.com/health-fitness-1/97bcce70356d September 2013 : 1 (friend of author)
http://www.endofthreefitness.com/rhabdomyolysis-know-thyself/ September 2013 : 1
These all sound reasonably exclusive (the 2011 CF paper is specifically about a different time period than the cumulative-to-2005 CF estimate of 6, the comments all seem to be by different people, etc), so we can sum to get 5+2+1+1+4+1+1=15 anecdotal cases of CF. You can argue that some of this is double-counting that I just didn’t notice, but if I looked at a few more threads I could probably add some more aneccdotes, so let’s just call it even.
How many CFers?
Crossfit was founded in 2000; there are now 6100 affiliated gyms. The 2013 CrossFit Games Open apparently had 138k registrations; this was a sort of virtual online competition, it seems, so it seems like a reasonable proxy for total Crossfit participants. Let’s say half didn’t bother to register, so in 2013, there were really more like 300k CrossFit people. That makes 50 CrossFitters per affiliate, which given the high cost of CrossFit and intensive time-demanding training sounds pretty reasonable. How many CrossFit people have there ever been? Making the completely arbitrary assumption that the average CFer lasts one year and assuming linear growth from 1 person in 2000 to 300k in 2013, then there’s been 150k * 13 = 1950000 CFers.
hence, just from these anecdotes, we might estimate a lower bound on the rate of 15/1950000
As it happens, (15 / 1950000) < (26000 / 262764948). To get the CF rate just barely above the base rate, I’d have to increase the number of CF rhabdo cases to 193, since (193 / 1950000) > (26000 / 262764948).
So if you believe the null hypothesis that CFers suffer rhabdo at the exact same rate as the general population, then according to this set of numbers, I apparently managed to get 8% (15/193) of the way to the entire population of CF rhabdo cases just by reading 7 links. As much as I admire my own reading and link-clicking skills, I don’t find that very plausible.
Now, with this set of numbers, how many cases of CF rhabdo would we need before we had something statistically-significant? We’d need another 206 cases of rhabdo to hit p<0.05:
So our little handful of anecdotes gets us 7% of the way to the claimed conclusion. For the much-maligned anecdote, this seems pretty impressive, IMO.
Okay.
CrossFit is not that unique. It is just a type of working out hard.
I’m quite confident injuries result more frequently among those who work out hard.
I’ll concede rhabdo is more common among CrossFitters than the general population. The point I should have focused (exclusively) on is that that is exactly what we should expect.
We see lots of concussions in football; lots of tennis elbow among tennis players; shoulder issues with powerlifters; knee problems in runners, etc.
The article seems to me to be fear mongering. It is the nature of highly competitive pursuits that they involve injuries.
More rhabdo among CrossFitters is like saying there are more drowning deaths among those who go swimming.
Meanwhile, the risks involved in living a sedentary lifestyle abound.
Sure, but once you’ve conceded that yes, CrossFit has an unusual increased risk of a disorder both deadly and detrimental to fitness, then you need to deal with objections that CFers would be better off with the next alternative: CF can’t be the only type of working out hard, even if it prides itself on being the hardest work out around.
Modus ponens, modus tollens. That may just be a reason to avoid swimming as one’s recreation unless one prefers it so much compared to the alternatives. ‘Drowning’ and ‘rhabo’ seem much worse than ‘shoulder issues’ or ‘knee problems’.
Conceding there are risks inherent to CrossFit (or anything) is a good reason to consider alternatives. Then, you’ll see the alternatives have risks, too.
Then, you may personally decide to partake in any activities for which you are willing to accept the risks.
And again, CrossFit isn’t a magical, dangerous thing. CrossFit = a branded mix of strength/speed/endurance exercises. You can do it reasonably, or over-do it.
Rugby or football, on the other hand...
The article presented no data other than some evidence about meme propagation in the Crossfit community.
Rhabdo is a consequence of severely overexerting your muscles and is not specific to the types of exercise that Crossfit does. It is specific to motivation and the claim is that, basically, Crossfit overmotivates the newbies. Well, maybe. And maybe other fitness programs do, too. Without data it’s really hard to tell and so far I haven’t seen any.
This is news to me and of relevance to my exercise choices. Is it the consensus of all the people on lesswrong who have the name ‘gwern’ that following CrossFit’s workout of the day routine is on net detrimental and to be avoided in favour of something else?
Haha no way. I hadn’t even heard of rhabdo or CrossFit before I noticed this thread. I just read the article and realized it was a great showpiece for one of the rare circumstances where anecdotes can actually be informative.
Thankyou for explaining. Your reputation as an independent researcher is such that if you had researched the subject I’d just take your word for it. The expected value of information would have to be damn high before it would be worth looking into it myself to confirm. And even then my first thought would be “Value of information is high? Hire gwern at his going rate to do a more thorough analysis.”
From my experience (anecdotal observation) is that with Crossfit what the participant brings into it largely determines what they take out of it. Now perhaps not all Crossfit boxes(gyms) share the same culture. But where I go there is a focus on form and scaling of workouts. Also those that are serious about progressing know how to hold back because rhabdo would destroy their(my) work and gains. Those who have no real goal except some loose idea of improved fitness and health never seem to push themselves hard enough to do damage. I’d say rhabdo would take a unique kind of desire to win over the pain to achieve.
Just to brag and promote: after a year of CF I’ve gained 6kg~ of muscle mass from 78kg to 84kg at 185cm. Crossfit is a tool to achieve fitness goals it doesn’t provide the goals or the motivation just the means exercise both.
I believe that people have some built-in warnings to keep them from hurting themselves, and it’s a cultural pathology to make ignoring those warnings into a virtue. It’s one thing to push through pain in an emergency or to increase your capacities, but it’s another to keep hurting yourself just to prove that you can.
More about injuries being common at Crossfit.
Here’s an example of a workout by Scott Sonnon, who encourages athletic ambition while making serious efforts to keep people from getting injured. This is a free workout he’s offering because people need free, useful things when the federal government is semi-shut down.
I generally agree with your sentiments. There is, however, a relatively tricky balance to achieve when attempting to optimize athletic performance.
I think overtraining has become a bit of an epidemic among novice strength trainers, and “less is more” can be a helpful lesson to learn sooner than later… but extreme athletic results often involve extreme training methods. Injury is a line that is always (very) detrimental to cross, but not pushing yourself close to that line can result in you failing to reach full potential.
You could argue that optimizing for some athletic output is not a wise use of resources anyway, especially given the risks (and I might agree with you) But it just may take the most extreme training to produce the most extreme (and optimized) results.