I must say that I pretty impressed with
this article. While I support the notion that a solid strength foundation provides a healthy chasis for any given runner, I've always raised an eyebrow at some of the "all or nothing" claims made by those who are strict CF and CFE followers. Let's just say that this post puts to rest quite a few claims and I'm sure future posts will address some others. After reading through this, I just wanted to snap my fingers and say "Damn!". There is so much goodness in this that I'm just going to post it below:
Crossfit endurance, Tabata sprints, and why people just don’t get it
Not terribly long ago, I stopped dating a girl because she did crossfit.
Okay, it wasn’t the only reason, but
it was a major factor. I mention this not to show how messed up my
dating life/requirements may be, but to show how strongly I feel about
the marketing scheme that is Crossfit. I’ve always wanted to write a
blog post about it, but the article in this months Runner’s World has
finally pushed me over the edge. I’m writing this blog to give a 2nd
opinion and to combat the marketing hype that surrounds crossfit. I
wouldn’t take much offense to crossfit and would let it do its own
thing, except when you start telling people that this is the way of the
future and that Ryan Hall would run faster if he did this stuff , then I
have a problem (Yes, CFE founder has made this claim)
For this post, we’ll focus on
Crossfit Endurance because it got some major publication in this month’s
Runner’s World and has been getting some hype lately. If you were at
my presentation at the American Distance Summit in North Carolina, you
got to hear me take a few jabs at crossfit (and Renato Canova even threw
in a jab or two!). Since it’s a question I get asked a lot, lets take a
look at crossfit endurance.
The claim and exploitation:
Crossfit Endurance and CF in general
is a randomized non-system of training. It’s basically a set of random
workouts that are high intensity circuit based workouts. In CF this
refers to a variety of high strength circuits and in CFE it combines
this with high intensity intervals like the famous Tabata “sprints”
(sets of 20sec hard/10sec easy). There are no easy runs. It’s simply
mix short intensity work with slightly longer high intensity work and
that’s all you get.
Crossfit exploits a couple different
natural reactions people have to get people on their bandwagon. First,
they create a straw man “us vs. them” mentality. We’ll go over this
straw man tactic a bit later, but they try and cultivate this idea that
just because it’s different and new means its got to be better. They
throw in some pseudoscience or misinterpretation of science and they’ve
bolstered their selling point. Further exploiting peoples natural
habits, they promise better results with less time commitment, which in
today’s “busy” world is probably the number one selling point for many
products or ideas. If you’ve ever watched late night infomercials, you
might start to see some similarities…
Lastly, once you’re in they do
something pretty creative. They first created their own new performance
metric on which you’re judged. Because being good at all the other
methods of establishing performance isn’t good enough, so now you’re
judged based on some criteria that crossfit develops. Being a
specialist at something is apparently bad? Additionally, they really go
after this hard work/pain = improvement and results idea. This is also
known as the Rocky effect. But if you’ve been in the coaching business
long enough you know that hard stupid work doesn’t get you anywhere.
You can’t just do work that is painful just because it hurts and expect
to get better.
Getting beyond some of the basic
philosophical tenants of CF that are ridiculous, let’s look at some of
their claims in regards to endurance performance and training.
What crossfit doesn’t get:
The central claim is that you can
get the same endurance benefits (or better) from doing high intensity
work and limit any slower to moderate paced running. They go on to
claim that endurance training ages you faster and is detrimental to
performance. Their claim rests on their misunderstanding of VO2max as
being equal to or critical to performance.
Let’s use their main research backed claim to look into their claims.
Tabata sprints and the high intensity misunderstanding:
A researcher named Tabata did a
series of studies on untrained and then moderately trained individuals
in which he gave them a workout that consisted of 20sec hard/10sec rest
for 4minutes. When this program was researched, they noted that VO2max
increased by a large amount and that certain aerobic enzymes also
increased. Using this and similar studies as their basis, CF has
championed the idea that you can get the same, or better, performance
off of doing intense work like that done in the study. Lets use this as
a way to look at why these claims are false.
#1 VO2max does not equal aerobic performance:
While I’ve written before about the
measurement of VO2max and how it relates to performance and you can read
more in depth on it in those blog posts, it bears repeating the
conclusions reached by Vollaard et al (2009):
“Moreover, we demonstrate that
VO2max and aerobic performance associate with distinct and separate
physiological and biochemical endpoints, suggesting that proposed models
for the determinants of endurance performance may need to be revisited
(pg. 1483)”.
The basic idea is that VO2max and
performance are separate things. Just because VO2max is increased or
decreased, does not mean that performance will change to the same degree
or even at all. This is a key concept to understand because often
times studies will track training’s effects on VO2max and not
performance. For instance, in much of the research cited by CF or even
cited in journal articles that talks about the benefit of high intensity
training or strength training, they talk about changes in VO2max.
#2 Intervals increase aerobic ability of FT fibers
At the coaching clinic I presented
at Renato Canova made a nice point that somewhat fast interval training
can increase the aerobic ability of Fast Twitch fibers. It’s best to
think of it as an interplay between FT and ST fibers. In that different
intensities and volumes will increase aerobic or anaerobic enzymes in
each type of fibers along the spectrum. What that means is that
although high and low intensity might both hit similar aerobic enzymes,
they do so in different ways and in different fiber types.
#3 Why does VO2max improve?
Understanding why VO2max improves is
another key to understanding this whole debate. VO2max does not simply
reflect aerobic ability. Instead VO2max is influenced by several
mechanisms. First off, if you’ve read Noakes central governor or if
you’ve read recent research on VO2max testing protocols, you’d know that
VO2max isn’t an actual max. You’re body self limits it. One way to
improve VO2max in a test is to be familiar in pushing closer to that
“edge”. If your body knows you can go there, it loosens the limits a
little bit. Very hard interval training lets the body know it can
handle high stress loads.
Secondly, we know that VO2max is
influenced by muscle fiber recruitment. So if we increase the amount of
recruitable muscle fibers during a test, the VO2max will rise. What’s a
way to increase muscle fiber recruitment? Sprinting, strength training,
etc. It’s one of the reasons why you see VO2max increases in untrained
athletes but not so much in trained following strength training. The
trained ones are pretty good at recruiting more and more fibers as they
get closer to fatigue. The untrained, not so much.
#4 What Happens when we build a base and follow it up with intensity?
A major problem with research
studies is that they are all short term. It’s the nature of the beast.
But let me pose a few questions to all of you.
What does the typical recreational endurance athlete do?
If you answered jog around or do
easy and moderate runs with little hard workouts you’d be correct. Most
recreational runners for instance simply go run. Why does this matter?
What happens when you take people just doing mileage and add intensity?
If you answered they improve over a
short time, you’d be correct! Think back to your HS days when you spent
a summer building a base of almost just mileage and then you hit the
season and your coach starts throwing interval training into the mix.
You get a nice boost in performance right? This is essentially what
happens in these research studies. They take recreational runners who
just do easy/base stuff and then throw 6 weeks of training hard on them
and they improve. Ask any coach and they’ll say this is just a simple
old school peaking/training program. In fact, it might resemble your
typical HS application of Lydiard training.
#5 What CrossFit endurance does is reminiscent of training done in the early 1900s:
I harp on people to know there
history so that they don’t repeat training mistakes. In the history of
endurance training it’s been a constant back and forth between intensity
and volume of work. Early on there were very very big swings. So we
went back and forth between training that was almost all easy slow
running and that which was all hard interval training. As training has
evolved we’ve gotten closer and closer to that sweet spot and mix.
What CFE has done is ignore all that
and try and go back to a time when all that was done was very hard very
fast interval work. It worked to a degree, but performance got much
better when we modulated things so that there was a nice mix.
Essentially, Crossfit is living in like the 1940s. We’ve learned from those times and evolved.
#6 A straw man of LSD vs. high intensity:
Crossfit, and many others, typically
create a straw man where they compare their training to a type of
training that isn’t used but by very beginners. They paint running
training as almost all LSD (long slow distance), when the reality is if
you look at any elite, college, or high school training program there is
a nice blend of volume and intensity. No one is just jogging around
each day. Yet that is what they have you believe. This even happens in
research when they compare interval training with just jogging around,
as if jogging around was the norm for training.
What happens in the real world of
course is that there is a nice mixture and blend between volume and
intensity. Essentially, they are arguing for something that doesn’t
occur.
#7 Two ways to improve aerobic endurance
In fact, if you look at how some
endurance adaptations happen, you can see that to increase things like
mitochondrial density, several different intensities trigger similar
adaptations. This goes along with the point on enzyme activity and
FT/ST fibers. But if we look at this nice graphic from Laursen (2009),
we can see that two different pathways to achieve some of these
functional adaptations are activated by endurance and interval
training. So why the heck would we want to use only one pathway when
two different means of getting these nice adaptations are there. If you
just attacked the problem from one side, you’d maximize that side
quickly and have nowhere to go!
Additionally, we know that
repetitive stress and activation of signaling pathways is what triggers
adaptation. It’s one of the reasons why we train pretty much every day
for maximum performance even if some of it is low intensity. That low
intensity easy to moderate work helps to enhance recovery and applies a
consistent signal for adaptation. Pure rest in this case isn’t better
(which is often the counterargument).
#8 Periodization matters:
It seems simple enough that people
would know that how you plan and periodize training matters. Training
isn’t a random collection of hard exercises or workouts. There has to
be some sort of logical sequence and progression. If there’s not, then
you can expect to get exactly what you trained for, random results.
The bottom line is that so called
high intensity interval training (HIIT) which is the new fad word with
strength coaches is good. But for endurance performance it’s even
better when it is supported! You have to support it with something.
Endurance work of various kinds and even pure speed work (with lots of
recovery) serves as support for the intense stuff.
#9 Interaction matters:
Endurance and strength gains fight
each other a bit for adaptation. While I don’t want to get bogged down
in the details, if we look at the signaling pathway for some endurance
adaptations and then muscle hypertrophy which are two goals of CF and
CFE, we can see that they interact and in fact impair each other in some
cases. For example, doing endurance work right after strength can
impair hypertrophy because the mTOR pathway(which signals hypertrophy
among other things) is basically switched off with endurance work. This
isn’t meant to show that they are mutually exclusive, but instead to
show that when you do things matters. Sometimes a whole heck of a lot!
Thus why you have to think about and plan things, not just do random
hard workouts.
This goes for not only sequencing of
endurance and strength work, but also in regards to sequencing
different strength workouts. You have to know what pre-fatiguing
muscles does to the subsequent training effect. And you have to know
what the effect is on the Central Nervous System. Crossfit doesn't
think about this at all. They don't care.
#11 Individualization
My number one pet peeve. There is
no individualization. Workout of the day. That's the norm. Beyond
that, everyone does the same crap for the most part. I could go on for
days on the importance of individualization, and CF and CFE fail
miserably.
What does this all mean?
What happens in the long term?
Again, I’m going to ask a rhetorical
question, for you HS coaches out there what happens if you mess up the
balance and do too much intense interval training after that base
phase? The answer is the kids fried. You see it all the time in High
School. A kid hits the interval training hard, runs some amazing early
season times and then fizzles out and is fried by the end of the year.
That’s what happens training wise. If you want lactate proof, this is
what happens aerobically if you mess things up. You shift the balance
to working anaerobically too much (Test #3) and you produce more lactate
at each pace, and you are done!
The reason is that there is an
interplay between easy to moderate running and intense running or even
strength training. If you work too much on the intensity or strength
side you shift things towards that way. In practical terms your lactate
produced at each speed might go up or you might decrease aerobic
ability a little bit. Same goes if you do too much volume with not
enough speed support. You’re speed side would be neglected so that
would go down. It depends on what you are training for but achieving
some sort of balance is key.
Additionally, if we look at very
long term implications for performance we know that the foundational
aerobic mileage does a few things. First in long term studies on Cross
Country skiers, the high volume of training created a fundamental shift
in fiber type towards those which improved their performance. So we got
a ST fiber type shift for guys who needed lots of ST. Secondly, the
high volume of training leads to long term increases in efficiency.
Yes, high intensity work or even lifting can do this too but again it’s
through different mechanisms. Lifting for example can increase
efficiency via modulating stiffness of the system. Or essentially
creating a stiffer spring. High Volume training on the other hand works
via increase the efficiency of both motor program patterns (because of
the repeated nature) and at the muscular level in terms of oxygen
utilization and waste product removal. Again, two different ways to hit
the same functional adaptation (improved efficiency), so why would we
just want to work on one of them.
So we have research showing that in
very elite runners, long term high volume training is needed to make
functional changes. We have practical experience in that throughout
history we’ve shifted towards the volumes we do now and that practically
every single good runner does a solid amount of mileage (with good
intensity mixed in) and we have the theory of why mileage should work.
If we simply put crossfit endurance through the same kind of review we have:
Research-
short term studies on high intensity training shows improved VO2max and
in some cases performance, but we have looked at why those don’t apply
neatly already. No research on crossfit endurance in particular
Theory- It goes against all known
scientific theory for how endurance performance should be improved and
how it actually happens.
Practice- No good runners do it. We
know from history what happens and what kind of performance you get
even if you do a lot of high intensity work with very little volume.
And lastly, it doesn’t help that they subscribe to every fad from diet to pose method of running that there is.
Finally, if you want a very
interesting research approach to the high volume/intensity paradigm read
Stephen Seiller’s nice summary here:
And finally, I’d like to point out
that finishing and racing are different. I’ve heard far too many times
that so and so did crossfit and finished a marathon so it must work. No
offense and sorry to sound elitist, but if I took off 6 months and did
nothing I could still finish a marathon. It doesn’t mean my program of
doing nothing worked.
What does this all mean?
While this was a lengthy rant, it
only touches the surface of the Crossfit or Crossfit Endurance
phenomenon. My point wasn’t to critique everything they did (that might
be later) but to teach you why some of their claims they make, even
research based claims, might be wrong.
In the future we’ll look at some of the specifics behind crossfit.
