After seeing a woman break 24 seconds and I think we can stop the discussion of "IF" the LZR suit is faster and start thinking "how much faster".
The previous line of suits (Fastskin and so on) were pretty similiar to a shaved swimmer. Sure - they do feel like they make you float, but overall the times seemed to move along "in line" with what I would expect to see in terms of improvements in the sport. If the previous suits would have been that much faster than shaving, you would have never seen people just using the legskins. By the way - for us Masters swimmers there was always the added benefit of keeping in all the "extra layers of skin".
So how much faster are the LZR suits ?
If I had to guess based on the results so far, I would say 0.25 to 0.30 per 50 and double that for the 100. I can see the Bernard going 48 low in the 100 and I can see Sullivan getting close or just breaking the 50 record. It makes sense that Libby Lenton would swim a 24.2 or so in the 50.
I think one of the top regular teams out there should do a test - you need a good amount of world class swimmers training together to be able to do a test. Here is the test I would propose:
8-10 swimmers
2 days of testing
4x50 on 10 minutes all out
Day 1 - swim 2 with a Fastskin2 followed by 2 with the LZR
Day 2 - swim 2 with the LZR followed by 2 with the Fastskin2
Get the averages of all 10 swimmers - maybe drop the high and low and there you go.
Why do the test ? I would HAVE to know. Swimming is a big part of your life and you just set a massive PR using this new technology - my very first question would be " How much was me and how much was the suit?"?
What your stats are not taking into account is that as you approach the far end of the spectrum in times such as a Michael Phelps the time improvements are typically mush smaller...and far more significant.
An old fat guy that goes 2:00 and is around 17 seconds slower that the fastest time presently able to be swum by a human is far more likely to see much bigger time drops than someone swimming around the 1:48 range.
The suit may only have a .05% effect for a Phelps but may have a 1-3% or more for people far off that end of the spectrum.
Which stats are those?
I have always maintained that the improvement will depend on factors like stroke mechanics, swimming speed, body position, body type. I also think that it may well depend on the course (SCY vs LCM, for example) if underwaters are significantly enhanced by the suit.
A well designed experiment will control for these variables.
Any experiment I do is specific to me and swimmers like me, certainly. Honestly, I really only do them for my own benefit; I'll post the results here for others' information but I'm not trying to make a definitive, more general statement. (If I wanted that, I'd publish.)
And Paul...I'm pretty sure when Schubert was talking about his 2% he was referring to top-level swimmers, so don't start backing away with this weak 0.05% stuff....if he was right, then the effect might be even greater for Clydesdale swimmers, assuming the zippers and seams stay together...:)
Statistical significance never proves anything
You'd show that the correlation is unlikely to have happened by chance (randomly). But you still have the whole "correlation is not causation" thing -- which is where we started all this -- and the need to control confounding variables. Gaash contends that there are none, and I respectfully disagree (ie, opinion). No way to know until you do the experiments.
It looked to me like Kitajima was not wearing a LZR at the Olympics,does anyone know?Based on my experience a B-70 is definitely faster for me in free,and not in BR(based on meets and in a workout swimming 50,with rest each way.)The Olympians clearly thought the full body suit was faster with free,but most men chose leggings for the other strokes and most women chose highnecks only for free also.I guess the restriction in up down motion(SDK and fly/BR) more than made up for the decreased drag,but that is a guess based on observation.
.. all I am saying is that the probability that these drops in times were not due at least in part to the LZR is low given the data. It MAY be true, but it is UNLIKELY to be true...
You are missing the point. I have very little doubt that the drops are statistically significant, but the data are simply insufficient to attribute that cause to the LZR no matter how many virtual coins you feel like tossing.
Please google or read up on "confounding variables." Any textbook in Epidemiology has a good description. Also check out the Bradford-Hill criteria for assessing the evidence of causation.
What your stats are not taking into account is that as you approach the far end of the spectrum in times such as a Michael Phelps the time improvements are typically mush smaller...and far more significant.
An old fat guy that goes 2:00 and is around 17 seconds slower that the fastest time presently able to be swum by a human is far more likely to see much bigger time drops than someone swimming around the 1:48 range.
The suit may only have a .05% effect for a Phelps but may have a 1-3% or more for people far off that end of the spectrum.
I think that's very likely. Tight suits would logically have a streamlining effect on, um, certain body types.
Gotta love the math geeks....spend all their time looking over the numbers and formulas and missing whats happening all around them. Kind of like our politicians.
George, I was only pointing out your point about the cost of the suit is moot because none of these athletes paid for the suit. "Justifying the expenditure" doesn't make sense when there was no expenditure.
Whatever value ... the terminology is really not important. Again, no one is saying that it PROVES anything... all the whatever value means is that the probability of the LZR not doing anything and this result having happened is low. Yes, doesn't prove anything, but I will use my analogy from before, given this information, if you had to bet someone whether the LZR helps or doesn't help, for even money, which side would you take? Thought so.
You mean alpha :)
You're kind of missing the point, though. This is what I've been arguing with Chris about. Statistical significance never proves anything. We could look at time drops for each year in the past decade, and correlate that with a binary value for whether the LZR was available in that year (1 for 2008, 0 for all other years), and I bet we would get a low p-value. Obviously 2008 has been a big year for time drops, and you can just eyeball the data and see that it's an outlier. But that does not prove that the LZR makes people faster, and it doesn't say anything about drag reduction versus expectation.
Not saying there are none.. all I am saying is that the probability that these drops in times were not due at least in part to the LZR is low given the data. It MAY be true, but it is UNLIKELY to be true. It's like flipping coins. If I have a coin I'm not sure is real or weighted, and I flip it 20 times and I get 19 heads, while it is POSSIBLE the coin isn't weighted, it is much more likely that it is. If I flip it 1 million times and I get 999,999 heads. I GUARANTEE YOU the coin is weighted (or the toss) Now, whether or not it's worth the money is an entirely different question that depends on the buyers utility function.
You'd show that the correlation is unlikely to have happened by chance (randomly). But you still have the whole "correlation is not causation" thing -- which is where we started all this -- and the need to control confounding variables. Gaash contends that there are none, and I respectfully disagree (ie, opinion). No way to know until you do the experiments.
I don't need to google anything. Yes, it is possible that the changes are not attributable to the LZR, but this is still unlikely even in light of other variables whos contributions ARE more or less known (training methods/etc which are always changing and yet their contributions have never led to close to the drops seen recently, the shuffle of older competitors out and newer competitors in which has also generally "normalized", etc. etc... again, the effect of many of these variables can and has been observed in historical time drops prior to the release of the LZR). Furthermore, Speedo claims the LZR reduces drag in tests, competitors claim it increases bouyancy etc, virtually every world record broken within months of its release, and almost every record was broken with the LZR,etc. etc. etc. it doesn't take a degree in statistics, only common sense to see that the LZR almost certaintly has an impact. It almost seems like some here are trying to convince themselves the LZR doesn't have an impact to avoid purchasing it. I wouldn't spend $550 on a swim suit either. But I'm not going to pretend that I don't believe the LZR has a positive impact on performance simply because it has not been proven in a rigorous manner.
You are missing the point. I have very little doubt that the drops are statistically significant, but the data are simply insufficient to attribute that cause to the LZR no matter how many virtual coins you feel like tossing.
Please google or read up on "confounding variables." Any textbook in Epidemiology has a good description. Also check out the Bradford-Hill criteria for assessing the evidence of causation.
