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Is a 'slow' swimming pool impeding world records?

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Re: Is a 'slow' swimming pool impeding world records?

#241

Post by thaumasiotes »

_heimdall wrote: post #29
echoangle wrote: post #25

Earlier quoted context omitted.

Being good at swimming doesn’t mean you can evaluate the pool performance better than everyone else. I trust someone running a CFD analysis of a pool more than a competitive Olympic swimmer when it comes to the effect of pool depth. It’s very hard to make accurate statistical assessments from intuition. Edit: maybe I’m not making myself clear: I don’t doubt they are slower in the current pool than they were before. B…

You don't necessarily need to do an in depth study of the pool when every Olympic swimmer in it fails to meet their own personal records. A study may be useful to understand why depth still matters beyond the 2m point, but a study isn't needed to show that swimmer performance is impacted.

> You don't necessarily need to do an in depth study of the pool when every Olympic swimmer in it fails to meet their own personal records.

This is a weird standard. Out of 200 people doing anything, how many do you expect to set a personal record? Say you drive to the grocery store. Are you setting a time record for the trip more than 0.5% of the time?

Re: Is a 'slow' swimming pool impeding world records?

#242

Post by echoangle »

AnthonBerg wrote: post #109
echoangle wrote: post #42

Earlier quoted context omitted.

The can maybe intuit being slower, but I doubt they can accurately tell you that it’s because of a different pools depth. There are a lot of other variables that could be the reason.

Do you have links available to any peer-reviewed scientific literature on which you base your theory that – just to make sure we’re on the same page — the theory that it is difficult to the point of impossibility for people to correctly ascertain that the depth and construction of the pool they swim in has no effect on their swimming dynamics, efficiency, and competitive performance?

Isn’t that the null hypothesis?

I have these data points:

1) The pool is shallower than normal in this Olympic

2) The pool seems to be slower this Olympic

3) swimmers seem to think it’s because the shallower depth

4) people responsible for building the pool say the effect of depth is negligible

5) there are other things that can be different about the pool except depth because the pools aren’t strictly standardized in their properties

My only claim was that point 3 doesn’t tell me a lot because I find it very plausible that you can’t really detect the reason for the slowness just from swimming. I don’t have positive proof of that though.

Re: Is a 'slow' swimming pool impeding world records?

#243

Post by echoangle »

mmmrtl wrote: post #105
echoangle wrote: post #39

Earlier quoted context omitted.

Or maybe there’s something else going on? There are a lot of other variables in a pool except depth, no? Maybe water tension, density, viscosity? Someone else mentioned the walls of the pool also influencing the wave properties in the pool. Just noticing the pool being more shallow and people swimming slower doesn’t mean that’s the reason.

Explain to us how water "tension", density, and viscosity are variables that would change? It's just water, and temperature is set at ~25 C. The shape of the pool and gutter setup are the only major factors at play, assuming the filtration system isn't causing major currents.

It’s not demineralized water though, have you ever added a tiny bit of soap to water and it immediately reduced the surface tension? I’m not saying there’s soap in the water in France obviously, but there’s a lot of other additives that could theoretically affect water properties even with a fixed temperature.

Edit: for example, compare salt and fresh water properties here: https://ittc.info/media/4048/75-02-01-03.pdf#page2

At 25 degrees, fresh water has a Viscosity of 0.000890 Pa⋅s and sea water has 0.000959 Pa⋅s. That’s an 8% difference in viscosity by adding NaCl to water. Is it that strange that there could be a 1% difference in viscosity for example by having different additives in the pool water?

Re: Is a 'slow' swimming pool impeding world records?

#244

Post by paganel »

We’ve just got a huge WR in the 100 men sprint by Pan Zhanle (just 19 years of age, the future is all his), I have no sympathy for those crying after WRs, maybe they’re not that good to begin with.

More generally, and talking about being good, it’s noticeable how the US, the biggest force in swimming, is going through a change of generations, as their only remaining star is Ledecky, who’s on her fourth Olympics. The Russians are also missing, they always used to have one or two super-stars ready to push the Americans to the limit (think Popov and Pankratov). The Aussies are doing a very fine job, and fair-play to them for that, but they’re also kind of not up to the highest levels in the men’s competition.

Re: Is a 'slow' swimming pool impeding world records?

#245

Post by spike021 »

hot_gril wrote: post #186
lacoolj wrote: post #96

So it's more shallow, which is a problem. Like if you trained for track on pavement vs rubber vs sand, you're going to have different results, even if "everyone has the same environment" not everyone's body will have the same relative response. I don't like that assumption that just because it's the same for everyone means the difference will affect everyone the same. Are France competition pools across the country j…

Plenty of pro sports have variation in conditions. World Cup soccer is played outdoors with rain, heat, whatever. Rain matters even more in Le Mans, where time records are being set. It doesn't really matter as long as it's cool to watch.

In baseball too, you have things like playing in LA or NY vs playing in Denver with thin atmosphere that completely affects movement of pitches as well as how well they fly through the air.

Re: Is a 'slow' swimming pool impeding world records?

#246

Post by Scarblac »

thaumasiotes wrote: post #241
_heimdall wrote: post #29

Earlier quoted context omitted.

You don't necessarily need to do an in depth study of the pool when every Olympic swimmer in it fails to meet their own personal records. A study may be useful to understand why depth still matters beyond the 2m point, but a study isn't needed to show that swimmer performance is impacted.

> You don't necessarily need to do an in depth study of the pool when every Olympic swimmer in it fails to meet their own personal records. This is a weird standard. Out of 200 people doing anything, how many do you expect to set a personal record? Say you drive to the grocery store. Are you setting a time record for the trip more than 0.5% of the time?

These athletes plan their whole training and fitness regime for years so that they are at their absolute best at this particular day.

Tbh I don't do much of that sort of thing for my grocery store trips at all.

Re: Is a 'slow' swimming pool impeding world records?

#247

Post by [deleted] »

anigbrowl wrote: post #200
DiggyJohnson wrote: post #194

Earlier quoted context omitted.

> should Why do you believe this should be the case? Keep in mind the majority opinion of most forms of racing and other competitions is to reward competitors for their qualifying or heat performances by assigning the most valuable starting positions to the top qualifiers. This is generally considered more fair than randomizing the final’s lane assignment (or grid order, etc) because it reduces the chance of BS in th…

I get it with motor racing like F1 because of the linear nature of the track, plus during the qualification laps they have a clear track and are not jockeying for position. My reservation with swimming is that if you were randomly assigned to a middle or side lane in the qualification stages, your advantage or disadvantage is compounded as the competition proceeds. It's not clear to me how lane assignments are conduc…

[deleted]

Re: Is a 'slow' swimming pool impeding world records?

#248

Post by Scarblac »

echoangle wrote: post #44
Xcelerate wrote: post #33

Earlier quoted context omitted.

I trust the swimmers’ intuition far more than an ad-hoc CFD analysis. Plus the shape of the pool itself isn’t necessarily the only variable that might be affecting the race times. The gold standard would be an empirical randomized controlled trial to compare two pools, assuming you could hide “which pool” from the participants.

I don’t doubt that they are slower, I doubt that it’s the pool depth. To be more accurate, i have no idea if it the pool depth, but a swimmer saying that it is doesn’t tell me a lot. I’m not sure if the intuition of a swimmer can differentiate between the pool depth effect and other effects that could influence performance. I don’t doubt that something is making them slower, but i don’t believe it’s pool depth until…

Wouldn't they notice the extra turbulence affecting their legs?

Re: Is a 'slow' swimming pool impeding world records?

#250

Post by thaumasiotes »

Scarblac wrote: post #246
thaumasiotes wrote: post #241

Earlier quoted context omitted.

> You don't necessarily need to do an in depth study of the pool when every Olympic swimmer in it fails to meet their own personal records. This is a weird standard. Out of 200 people doing anything, how many do you expect to set a personal record? Say you drive to the grocery store. Are you setting a time record for the trip more than 0.5% of the time?

These athletes plan their whole training and fitness regime for years so that they are at their absolute best at this particular day. Tbh I don't do much of that sort of thing for my grocery store trips at all.

> These athletes plan their whole training and fitness regime for years so that they are at their absolute best at this particular day.

The only way this could actually happen is if they intentionally sandbag their performance starting several years in advance -- and continuing indefinitely -- which would prevent them from qualifying for the Olympics in the first place. It's not a possibility.

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