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:
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:
NoelKeith has put his own response up HERE
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.
Would you be happy if I posted your email on the blog to add to the debate?
- 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.
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.