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Matt S
September 10th, 2002, 02:32 PM
Does anyone else swim open water times that seem to be ... a bit faster than physically possible? Here's my dilemma: I swam the Big Shoulders 5K this past weekend at Chicago. My time was fast, REAL FAST, 1:10.04. Or to put it another way, if I swam a pool 1500m (an event less than one third the distance) at that pace, I'd shatter my PR by almost a minute, or if I swam a pool 800m at that pace, I would beat my most recent swim at LC Nationals by 8 seconds. Now, I believe in the power of positive thinking, and Total Immersion, etc., etc... But, this is so far beyond the realm of the plausible, I am not certain whether I should be crowing or questioning.

It would be easy to assume that the course was simply measured a tad short, but this is not the first time I have had an open water swim bordering on fantatsy. Three years ago I swam a salt-water 3K in 40:20'ish, which again is a pace that would have shattered my 1500 PR, and is substantially faster than the pool 800 I swam 7 days before. I asked the meet organizers about this, and they assured me that this is the same, closely measured course they use for several open water swims each year, and that the added buoyancy from salt-water could account for the difference. I accepted that answer at the time, but now that I appear to have duplicated this feat in fresh water, I am wondering again.

To get to the point: does anyone else find that they are prone to swimming in open water at a pace they cannot duplicate in shorter pool events? Does anyone have any ideas about what might cause this?

Matt

emmett
September 10th, 2002, 02:48 PM
Hey Matt,

This obviously begs the question, "Do your turns suck, big time?" :)

Of course, I ask purely in a process-of-elimination, due-diligence sort of way.

pbsaurus
September 10th, 2002, 03:36 PM
We would need the vector measurements of the current too, plus any impact due to drafting off of others.

Interesting quandery there, I wonder if there have been any studies comparing pool swimming with open water. My open water times are a lot slower than converted pool times, maybe I have good turns:p

Leonard Jansen
September 10th, 2002, 04:08 PM
There are several factors to consider:
1) Are the currents, if any, going with your direction of motion?
2) Are you drafting? (Can be worth 4% or so.)
3) Are you a wetsuit-wearing wuss? <evil grin> (Worth 0-10% depending on how good your technique is already.)
4) How was the course measured? Did they even attempt to measure it?
5) Is there any wind/wave action pushing in the direction of motion?

I always take open water times with a grain of salt. Instead, I tend to measure progress by my place as a % of overall finishers and/or as a % of finishers in my age group. Not to mention wallowing in moral superiority over all the wetsuit people...

-LBJ

emmett
September 10th, 2002, 04:09 PM
Because of the effect of turns, swimming a long distance in a pool is VERY different, physiologically, than swimming in open water. Especially in a short course pool, where up to a third (and in some cases, more) of the distance swum is really part of the turn. While there is a lot of rest for swimming muscles diring this time, there is also the variable of oxygen use and replenishment that is WAY different in a turn-interrupted swim than in a continuous swim.

There are, in fact, so many variables that are radically different in the two environments that blanket comparisons between pool swimming and open water swimming are a fool's fantasy at best. The only real way to draw comparisons are on a swimmer by swimmer, event by event basis - and even then, only with lots of the variables concretely measured and inked in to your equations.

I know plenty of people who positively shine in open water yet are seemingly hopeless pool swimmers (and, among other things, their turns generally suck, big time).

Matt S
September 10th, 2002, 06:27 PM
Do my turns suck? I do have a tendency to breath in and out of them because turn-induced oxygen debt is a major factor in my swimming (and a major reason I hate SCY and love LCM), BUT I do streamline well on my side, dolphin kick, and generally don't lose ground off of the turn compared to my teammates. Another factor indicating they do not suck so bad as to be a causal factor is that I do swim SCM faster than LCM.

Drafting: as much as possible. I forgot to bring my contact lens, so I intentionally stayed in sight of another swimmer as much as possible (also so I could keep my head down as much as possible). Potential factor here; what does "4%" mean in terms of time? I did not draft as much in the 1999 swim, and hardly at all in the second half of the race, when I made up ground on the lead pack. But, as I've said, that was a salt water swim, and I know the added buoyancy does make a difference.

Currents, surf, misc. enviro factors. The Big Shoulders Swim is twice around a closed, triangular course (i.e. you start and finish at the same point) off the southwestern shore of Lake Michigan. If there are any scientific types who can deconstruct this reasoning, I'm listening. However, wouldn't any current pushing me forward in one direction push against me when I turn back the other way?

Short measured course and other idiosyncratic factors: I would buy that if this was only one swim, but I have a difficult time accepting that two different open water swims (out of the 6 open water courses in which I have competed in my swimming career), both of which use the same course year after year, would BOTH be so far off as to account for such a dramatic difference.

Thanks for your thoughts. I am trying to gauge whether I have a monster swim in me for the 1500 next year. The answer may well be yes.

Matt

Phil Arcuni
September 10th, 2002, 06:53 PM
As a 'scientific type' I can say that any current, wind, waves, etc. that aid you in one direction, and hinder you in another direction, will only make your net time longer (I'll spare you the algebra.)

Maybe, because Lake Michigan is really deep, it is really 'fast' :)

emmett
September 10th, 2002, 07:35 PM
If you try to swim in a "straight line" consider that a wind or current cutting across your swim will force you to swim a longer distance to account for side drift. This will be both coming and going.

If, as you say, the hypoxia produced by long glides off your turns is a major factor in your swim then that might be your answer right there. You may be giving up more, physiologically there than you get back mechanically from a long gliding pushoff.

strong440
September 10th, 2002, 10:49 PM
hey phil, my guess is that you are closer than anyone would think; if ya'll'l permit me a little background, including the fact that I was born on the shores of Lake Michigan, and know not only that it is deep, but also in some times and places it is shallow. Like, at the Ohio Street Beach it was very shallow when I swam the Big Shoulders at this time of year 2000, so shallow that I was touching the bottom from time to time on the return leg along the shore line. (As an aside, the original results showed me as having finished somewhere in the top 10 or 20, until I mentioned that I had gone for the 2500 rather than the 5000). Anyway, besides being very shallow at the time, the weather was perfect with very little wavelits and the water temperature delightful. I don't remember what the thermometer said.

But, to get to the point of the present question. I have taken the time to compare the times of the swimmers who swam the Big Shoulders in 2000 with those same swimmers times in 2002.
Thus in Matt's age group only 4 had swum both but their times were better by 12, 7, 2, and 11 minutes than the 2000 times. Moreover, seven of the same group had swum it in 2001 with times that were between 2000 and 2002, with only one of them not following the pattern. Since it is a public record I'll mention names, with times first in 2000, 2001, then 2002,leaving out the hour and seconds [is this a good place minutes only, or what?]:
Reeves 14, 12, 02. Layton 16, 15, 08. Platt 24, 28, 22. Schleifman 38, 33, 27. Those who swam only 2001 and 2002 were Mathieu who went from 21 to 08; Gibson from 14 to 10. Lundeen 18 to 13.

In the next age group, comparing times of all the men who swam it in 2000 and 2002 there were 10 out of 17 who swam it 2002.
Times went from 8 to 2 for Drake, 17 to 13 for Martin, 23 to 13 for Carpenter, 28 to 18 for (not Emmett) Hines, 33 to 20 for Richard of Ft.Wayne whose last name is listed variously as Cater and Carter, Kent Kirk from 37 to 24, Bertke from 43 to 28, Cornwell form 38 to 33, Berquist from 39 to 34, and Grogan from 51 to 47.

Similar time differences happened in ALL of the men who swam both 2000 and 2002 with times between for those who swam in 2001.

So, apparently the evidence is overwhelming that the course was absolutely ideal this year. And I would guess that the water was both deeper and cleaner, recalling that it was pretty murky two years ago, with some light rain before most had finished, if my memory serves true. With the glassy smooth surface, ya'll could breath without the extra headlift that is so slowing, and the good vision would have been comforting.

Just to show that I didn't ignore the women entirely in this instance, I'll mention that one of them swam the course in a time that was faster in 2000 by [ya'll'l never believe it if I don't spell it out, word for word] eighteen hundredths of a second (.18)!