Friday, April 24, 2009

Comments on the functional training debate

Here and at Keith's Theory to Practice site there has been some debate recently about the whole issue of functional training. This is an issue dealt with in Doug McGuff's Body by Science and something I explored a bit more in my interview with Luke Carlson.

A reader (Noel) of both Keith's TTP blog and this one sent us both a comment which he agreed I could reproduce here:


The recent posts about the BBS/super slow movement have irked me to the extent that I am compelled to write this email. While on the macro level I don't really care what they espouse, I don't think their claims are getting the critical examination they deserve.

Let me crudely characterise the debate as consisting of two sides: machine based, super slow, one set of failure based on published research (Dr McGuff) versus free weights, 5 reps or less, multiple sets based on coaching experience (Rip). I'm not suggesting Dr McGuff and Rip are in direct opposition (I don't know if they even know of one another), but I want to use two exemplars to discuss this issue. I
hope we can all agree these guys are experts, and they hold viewpoints that are contradictory. No one has the time to be knowledgeable in all fields, so normally we defer to experts. When the experts disagree it is time to examine the primary evidence more closely. The key thing here is our standard of proof: how strong must the evidence be before we accept it as true?

Now the BBS guys lean on the published literature. I went to PubMed, did a search for "resistance training one set failure" and the first relevant hit I found was:

METHODS: Twenty-one women were divided randomly into 2 groups: Group 1 (n=10) performed a single set of the leg press exercise once per week, while Group 2 (n=11) performed a single set of the leg press exercise twice per week for a period of 8 weeks. Throughout the duration of the study, an amount of resistance was utilized that allowed for a single set of 6 to 10 repetitions to muscular failure.

This seems to back up their claims -- but it is extremely weak evidence! 21 people is tiny, and 8 weeks is very short. Consider this: would you use a drug that had been tested on 21 people? I did a search for drug trial sizes (and perhaps Keith can say more here) and it seems a small trial is of the order of 300 people. Technically the
statistical power of this study -- that is, its ability to show an effect if there is one -- is very low.

To see the problems this study might have, imagine you had two groups of people, both of whom can lift 100kg on some exercise, with a standard deviation of 5kg. Imagine one group trains with protocol A, and the other with protocal B. After a year the group on A can lift 250kg +/- 12.5kg and the group on B can lift 200kg +/- 10kg (so group A gained 1.5x the strength and group B gained 1x the strength). The
difference in average strength is well outside 3 standard deviations, so this should be a very significant result.

Now what do you see after 8 weeks, assuming linear gains?

Group A: Mean = 100kg + [100kg * (8/52) * 1.5] = 123kg
Std. Dev. = 5kg + [5kg * 8/52 * 1.5] = 6.2kg
Group B: Mean = 100kg + [100kg * (8/52) * 1] = 115kg
Std. Dev. = 5.8kg

The difference in means is well within two standard deviations -- not a significant result. So see how the short duration of the study has made a significant result seem insignificant.

(This is fairly informal. If someone wants to calculate the actual p-values assuming, say, a population of infinite size [and therefore the t-distribution becomes the normal] that would be informative and more persuasive than my argument.)

(Also, see this:$=relatedreviews&logdbfrom=pubmed

This quantitative review indicates that single-set programs for an initial short training period in untrained individuals result in similar strength gains as multiple-set programs. However, as progression occurs and higher gains are desired, multiple-set programs are more effective.)

I'm not a researcher in the field of exercise science (or kinesology or whatever you want to call it) but a lot of the published research I have seen is of this type. This does not meet my standards of proof.

Now consider the evidence Rip has. It would be rejected by the BBS guys as it doesn't meet the criteria for publication: it doesn't control for variability, it isn't statistically analysed and so on. That doesn't mean it isn't evidence though. From his writing Rip
strikes me as a very methodical and very experienced guy. I must admit I am more inclined to believe him, based on his experience training hundreds of people over long periods, than I am to believe claims based on what I perceive as very weak published literature.

Finally, I want to address Chris' interview with Luke Carlson.

"Q: What do you make of Crossfit?...

A: It is entertaining to me that the three movements that all humans allegedly engage in just happen to be historically popular Olympic and Power lifts!"

Two things. First my understanding is that the term "functional movement" is used by Crossfit to mean a movement that carries over to other activities. It doesn't mean that movement mimics other activities.

I would think anyone could see that deadlifting and squatting are core movements. I guess Luke has never picked anything off the floor, or taken a dump.

"The vast majority, if not every HIT advocate that I know utilizes twisting/rotational movements. We use the MedX Core Torso Rotation machine - a $7,000 machine that targets the muscles involved in rotation of the trunk. This exercise is included in the working scripts for all of our clients."

The Crossfit orthodoxy here is that training midline stabilisation -- the ability to resist twisting -- is key. I did a little test with myself, throwing punches. It seems that I flex my obliques to avoid twisting so as to better transfer power from my hips to my upper body. I'm not trained at punching, but this way felt much better than
deliberately twisting my midsection out of line with my hips.

This response is also highlights an issue that I haven't seen anyone address yet -- these guys are not impartial. I don't need a $7000 machine to train my obliques, but the equipment manufacturers and the gym owners that have invested in them would like me to believe I do. In fact this is one of the primary reasons I dislike the BBS movement -- they want to make the trainee dependent on the gym to workout. In
contrast a barbell set is dead cheap, and free weights, be they iron, a rock, or a baby, can be used anywhere. I'd rather be self sufficient and teach people to be the same.

Finally, let me address safety:

First, there is lack of evidence to support machines being safer than free weights:

Let's also look at the injury rate, from the same site: 0.0035 injuries per 100 hours. Imagine I'm a real gym rat and hit the gym 5 days a week for an hour. That's 5 hours a week, or 260 hours a year, or 13000 hours over 50 years. With that injury rate I would expect 0.455 injuries over my lifetime of training. Worried?

Well, I'd better do some real work.


I answered thus:


thanks for the email. ....... A couple of things:

  • What I put up on the blog tends to reflect what I'm currently interested in / what I'm reading about myself. Sometimes there will be a spate of posts on posture. Sometimes it is about intervals. At the moment I'm reading alot and thinking about this functional training debate so that is what is getting posted. I'm glad that other people read the blog and like it but ultimately it is driven by my current interests.
  • Re functional stuff / deadlifting / squats - if Crossfit's point is about "carryover" effects of certain moves the HIT peopel woudl say that there is no carryover from one move to another - they are all different. Moves must be trained specifically. It is the strength that carries over as I understand it.
Would you be happy if I posted your email on the blog to add to the debate?

Keith has put his own response up HERE

I really enjoy such feedback and am grateful to Noel for it. I must admit that I still think people are not quite understanding what the HIT/BBS position is. There is always a reaction when something challenges the orthodoxy.

I think that Noel's comment about Luke Carlson re the squat and deadlift is wrong. We are back to specificity. Squatting and deadlifting with weight will make you stronger. Agreed. But they are different skills from squatting to take a dump or bending over to lift something up. The motor patterns are unique and specific. The stronger muscles from the deadlift will help but you the motor patter from deadlifting will not. That I think is the point.


Mike T Nelson said...

Interesting discussion.

Here are my thoughts.

I think the center of the debate is around "transfer"

As mentioned, this can be positive, negative or neutral.

Simply put
Positive transfer--weight training increases my performance on the playing field

Negative transfer---weight training DECREASES my performance on the field.

Neutral--no effect

While the DL may make you stronger on the DL (SAID principle---Specific Adaptation to Imposed Demand--your body will ALWAYS adapt to EXACTLY what you do), it may or may not increase your ability on the field.

What you need to test is:
Does a DL positively transfer to increased playing ability on the field? If yes, then the DL is good for you at this point in time. If not, then you probably don't want to do it.

While it is true that motor learning is specific (SAID), there is ALWAYS TRANSFER of some kind (pos, neg or neutral). The only "true" way to know is to test it on an individual level.

Beyond that, based on experience and some literature, you can guess at what you think will be best (but I would still test it).

Machine training, KBs, Crossfit, etc are all subject to these principles.

Also, as Luke knows, for ideal motor learning you need repeated exposures--reps.

Vladamir Zatsiorsky states in The Science and Practice of Strength Training, “practice as often as possible while staying as fresh as possible.”

This does not ONLY apply to skill practice, it applies in the weight room too! If you know that KB swings positively transfer to improved field performance, then you would want to do them more frequently as long as you are still getting positive transfer.

Not sure if I helped or hinder.

In regards to the literature, there are some data on low volume (HIT, whatever) and it seems to be only best for untrained people. While it is true that their are decreasing returns as the number of sets increase, there is still an adaptation beyond 1 set.

Rock on
Mike T Nelson
PhD(c), CSCS

Ketch Rudder said...

So-called "scientific" studies in exercise physiology are not scientific.

The sample sizes are too small and thus cannot get projected over a universe of humans.

Also, the universe never gets defined.

Are researchers looking to project results to a universe of 21 year olds, to a universe of 19 to 26 year olds, to a universe of 30 to 39 year olds?

Do all who are 21 have the same same VO2Max, with the same load potential, with the same height-to-weight ratio, with the same body fat to body weight ratio?

Also, none of the studies control for key factors of growth like sleep and diet composition.

Worse, no study ensures key biochemistry remains the same across all study participants.

The effects of aging become highly specific to any individual and only have a loose connection to a chronological age.

All studies from Academicians prove to be 100% invalid since such Academicians fail to understand the proper use of scientific methods.

Never do Academicians set-up the parameters for a proper study and then apply them to different sample sets taken from persons in different countries the earth over.

Given the glaring sham Academia is over exercise physiology, athletes and athletic-leaning persons can be sure of the following:

1. Through muscle training, anyone can actual increase contractile protein muscle fibers responsible for generating tension or force that allows us to move

2. Through energy training, anyone can improve their anaerobic systems and their aerobic systems and hence their power -- work over time.

3. Anyone can increase toward some upper bound their stamina, thrust, speed and skillfulness of movement (coordination).

4. Anyone can become more efficient in movement for a specific sport, thus lessening the effects of gravity, drag and lessening energy use through such movement.

5. With increases in stamina, thrust, speed, skillfulness of movement and efficiency of movement, anyone can increase their living performance both in sport and everyday life.

John Sifferman - Real World Strength Training said...

It's not my intention to spam, but I covered this subject on my blog not too long ago:

that pretty much sums up my thoughts on this debate.

and I've got some research studies that go into some of these details if anyone is interested.

Best regards,

John Sifferman NSCA-CPT
Fitness Professional

Anonymous said...

I just want to say a few things about what CrossFit is and is not.

We aren't bodybuilders. Our main goal is not to bulk up or to strengthen a particular set of muscles for aesthetic value.

We aren't Olympians. Our main goal is not to get as strong as possible with a few lifts.

We aren't a sport-specific training program. Any CrossFit trainer will tell you that if you want to get good at football, you practice football.

What we are is aimed at overall fitness and general physical preparedness for whatever life throws at us. We think that CrossFit is a great complement to any sport- or activity-specific training program but we acknowledge that we focus on the general at the expense of the specific.

With regards to the "functional" nature of our movements - yes, the motor recruitment patterns that we teach, especially in our more explosive movements, are specific to that movement. Specifically, we refer to four general areas of fitness (coordination, accuracy, agility, and balance) that must be practiced at the skill-specific level in order to be improved, and we do not claim that we teach every skill one encounters in one's daily life.

The reason that we choose the skilled movements that we do - the deadlift, the squat, the clean, the kipping pull-up, the push jerk, the double-under - is that we find that these movements are some of the most efficient to build the areas of fitness (strength, stamina, flexibility, and cardiovascular endurance) that do carry over into other activities.

Look at something like the push jerk. Instead of targeting the triceps, the push jerk starts in the lower body, uses a solid midline to transfer momentum to the upper body, and finishes with a huge balance requirement. This engages muscles throughout the body all at once - your quads and glutes for the dips, your abs and spinal erectors for the drive, and all of those little support muscles that have to engage in order to maintain balance. It also works shoulder flexibility both at the top and bottom of the lift. It's also a fast and explosive movement that can be chained together into fast, quick reps to engage a cardio-respiratory response as it trains strength, stamina, and flexibility.

Aside from the general vs. special argument, there's also the argument about the safety of our movements. This is where we usually compare crossfit movements to daily life movements. Even though the motor recruitment pattern may be task-specific, if a person cannot safely perform a deadlift, they cannot safely pick something heavy up off the floor. When you build the strength to deadlift, you build the strength to support your back while lifting something heavy. The movement is functional not because we think people need practice picking things up - we're fairly confident that most people can pick things up without practice - but because we think people need the muscular and skeletal capacity to pick things up without injuring themselves.

In short, the functional aspect of Crossfit is that you can build the capacity (not necessarily the skill) to perform everyday tasks, while the functional aspect of our movements is that they are efficient at building a broad general level of capacity that will form a solid basis from which to practice skill-specific tasks.

SB said...

But they are different skills from squatting to take a dump or bending over to lift something up. The motor patterns are unique and specific. The stronger muscles from the deadlift will help but you the motor patter from deadlifting will not. That I think is the point. But by the same token, I think the point of "functional" workouts is that doing heavy deadlifts will strengthen more muscles more quickly than anything you can possibly do on one of those expensive machines. And that greater strength does carry over (it's impossible to imagine how it couldn't) into other activities.

Look, Lance Armstrong's VO2max was somewhat specific to bike riding, and he hasn't won any marathons. But he still did manage to finish his first-ever marathon in 2:59. True, that's a long way from first place. But it's still one hell of a performance for someone who had never run more than 13 miles before. So while there wasn't perfect carry-over from his biking, there must have been SOME carry-over . . . otherwise, he'd have dropped out after a half-mile.

Chris said...

Thanks for the various comments guys. All useful stuff.

Smack MacDougal said...

The Crossfit folks have themselves a catchy name, a great name for selling.

The Crossfit folks preach a philosophy that seems acceptable on its face.

And then truth sets in and we discover that the CrossFit folks prescribe some of the most dangerous exercises anyone can do. athlete or not -- the clean, the push jerk.

For most, even the squat puts persons at high-risk.

The Push Jerk combines the worst of any bad exercise -- useless momentum that leads to wasted training time and joint damage to elbows, hips and knees.

The Clean has no practical application either to sport or everyday living.

The momentum and crazed load shift puts too much risk far over any reward from such a lift.

Besides, Olympic lifters take a life-time trying to learn how to make the Clean properly.

For almost all, including athletes, do not need to perform the (back) squat, ever.

Why? The back squat puts unneeded load on the shoulders, hips and knees through the lift.

Instead, athletes and fitness buffs ought to perform Bondarchuk step-ups instead.

When we breakdown the Crossfit message we get these:

1. Gymnasts learn new sports faster than other athletes.

comment: This CF belief is false. Gymnasts might have better athletic fitness that lets them PARTICIPATE in other sports faster. Yet, muscle stature has nothing to do with being able to learn and grasp the nuance of any sport.

2. Olympic lifters can apply more useful power to more activities than other athletes.

comment: CFers make another exaggerated claim. It's unlikely that an Olympic lifter would be much use in rowing, yet a rower, who builds legs with squats, could Olympic lift.

3. Powerlifters are stronger than other athletes.

comment: This claim might be true or it might not. More importantly, can a powerlifter handle a 40 minute half of rugby, a 10 minute break and another 40 minutes of rugby?

No one need join an expensive gym and waste their time working out on machines.

Machines serve one purpose -- to workout isolated muscles for those who have injured themselves and now are focusing on rehabilitation of those injured muscles.

Yet, what CrossFit offers amounts to greater danger to both athletes and everyday folks.

You Can Get FitYou can get fit for living or sport in a much better way. Anyone can do it too.

1. Daily StretchingCats awaken from naps and stretch, always. You should too. Start each day with a stretch routine. Get Stretching Anatomy by Arnold G. Nelson

2. Bodyweight Exercises with Sand in a KnapsackStanding and Supine Back-hand Pull-ups; 3-Chair Push-ups, Chair Dips; Jack-knife or Wall Pushups; Leaning Push-ups and Palm-up Pull-ups; Step-ups and Bulgarian Squats; Twist crunches, Leg Lifts, Leg Ups

3. Interval Sprints1.5 minutes of jog mixed with 45 seconds of sprint for 10 minutes

SB said...

For what it's worth, I don't think you have to train a movement to get stronger at it.

Example: me, dumbbell rows. I hadn't done them for several years, and last time I did them it was probably with 70 pound dumbbells or so. Then I spent a few years running, no lifting at all. For the past year, though, I've done a lot of pullups and deadlifts.

So the other day, I worked up to a heavy set of deadlift (3 reps at 395). Then, just for a lark, I did dumbbell rows to see how they felt. 100-pound dumbbells felt too easy, so I moved to a 110-pound BARbell that my gym has. Cranked out two sets of 4 reps, and it wasn't too hard (the hardest part was just balancing the barbell in one hand).

So I got 50% stronger (at least) in a movement that I didn't do for 7 or 8 years.

Chris said...


I suppose this comes down to what is a skill. Pullups and deadlifts would make the muscles involved in the rows stronger.

There is not much skill in the row, so it is easy to apply your new found strength.


Bryce said...

I don't want this to become a crossfit debate, as we're discussing SS/HIT here, but ...

I used to be a crossfit enthusiast, but moved away from it to work on some more personalized goals. I agree that some of what crossfit does can lead to higher chances of injury, but so what? So can football. I think some of what has been said here ... i.e. "no carry over," "no practical application" ... comes across as a little closed minded. There are applications for everything, and many people (including myself), have benefited directly from these lifts. For example:

I improved my vertical with the clean. I did no jumping practice or box jumps. The clean didn't make my jumping technique better, but it did increase my explosive power.

Onto the discussion of functional training, I'll say one thing about the deadlift. The deadlift has taught me how to use my body more safely. Before deadlifting, I didn't know how to set my back, lift my chest, keep my arms straight, drive first with my legs and then my hips, etc. I know that picking up a box or a couch is different, but because I have done a lot of deadlifting, I can now do those things more easily and more safely! Not only am I stronger, but I also do those things (set the back, lift with the hips) instinctively, because of all that deadlifting.

There is some carry over to real life here, and not just in strength gained . Those are just my thoughts.

Anonymous said...

I think the real debate between HIT vs Oly is this:

HIT proponents claim the best way to strengthen a muscle is through its complete range of motion, heavy and intense.

OLY/ballistics people say you have to train the body as a unit. So submax overhead squats or snatches, while not taking a hamstring or tricep through a complete range of motion, nevertheless trains those muscles to function as a one-body unit Just Like Moving, Lifting, Performing in real life.

I agree.

Chris said...


Thanks. This is where it gets interesting. THe clean made you a better jumper. But was that just that you got stronger through he clean and were therefore able to apply that new strength in the jump. The point i think is that you could have got the same muscles stronger with a different set of exercises. That the clean is similar to a jump is not relevant.

I think your points re the deadlift teaching good lifting habits are true and relevant.


Bryce said...


I definitely think that it was the strength/power gained from the clean that aided my jumping, so of course similar power gained from other lifts (jump squats, etc) could do the same thing. I only offered that as an argument to the assertion that the clean "has no practical application either to sport or everyday living."

I'm not alleging that the clean and deadlift are the only ways to get your posterior chain strong and powerful, or even that they're the best ways. I'm simply saying that they are useful, effective, and accessible. All you need is a barbell and weights! And ... you would need extremely complex and expensive machinery to truly match the benefits they offer. From barbell lifting, I am used to approach something that is heavy, preparing my body (positioning, bracing, etc), and lifting it. When I used to only use machines, I did not have this mental strategy for lifting built in. I did not know to keep my back arched because you don't have to when leg pressing. I didn't know to keep my abs braced when pressing overhead because you don't have to as much on a machine.


SB said...

I've never seen a machine that could remotely simulate a deadlift.