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Talvi 08-11-2012 12:49 PM

Quote:

Originally Posted by Richardsk (Post 30311)
I found this video, which seems to show, if I am right, that Ledecky is using a combination of two, six and four-beat kicks in the early stages of the race. http://www.youtube.com/watch?v=NUU2L...eature=related

Interesting Richard. So how does all this fit in with the TI "theory" that the kick contributes almost nothing to propulsion?? On the one hand it's a minor thing for me as I'm not interested in speed but on the other it's of great interest to me because it relates to the "feel" of the water while kicking. Understanding what's really happening helps me learn/relearn/modify perception etc etc I "feel" I do get significant propulsion (sometimes anyway) from kicking. So for me kicking more often or less often is not really the issue but whether kicking contributes to propulsion. TI posts etc I've read suggest it doesn't contribute but if it doesn't then why do elite swimmers kick, and why so much? It should be a waste of energy....

CharlesCouturier 08-11-2012 05:03 PM

The leg kick does not contribute to propulsion in longer distance events, regardless of if it's swam in a pool or open water.

However, a compromised body position (ie compromised balance) will have a negative impact on one's distance per stroke (it's obvious right?).

At that level, the level of pressure put early into one's catch has a detrimental impact on balance. Therefore, it is fair to state that whilst your leg kick can not contribute to propulsion, it does contribute to maintaining a proper balance, which in turn has a favorable impact on distance per stroke.

Richardsk 08-11-2012 05:29 PM

I read some interesting stuff recently from Brent S. Rushall, an Australian sports scientist based in San Diego. Basically he says the same as Charles. The kick does not provide propulsion but helps to counterbalance vertical forces produced by the arms and thus maintains good alignment.

A search under his name will lead to lots of interesting stuff.

borate 08-11-2012 05:48 PM

Quote:

Originally Posted by Richardsk (Post 30318)
I read some interesting stuff recently from Brent S. Rushall, an Australian sports scientist based in San Diego. <snip> The kick does not provide propulsion but helps to counterbalance vertical forces produced by the arms and thus maintains good alignment.

A poor kick may counter forward propulsion. Novice swimmers often report that they move backwards when simply kicking, owing to incorrect foot positioning, excessive knee bending or perhaps ankle inflexibility.

Talvi 08-12-2012 07:34 AM

Amazing replies guys, thanks! That all adds up to me. re the catch, I've been reading the article on Emmett Hines' site called The Dreaded Dropped Elbow. Although the temp in the lake is plummetting here 17'/62' I'm still eager to test it out as I'm sure my elbow is well dropped!

swim2Bfree 08-13-2012 03:56 AM

Quote:

Originally Posted by Talvi
So how does all this fit in with the TI "theory" that the kick contributes almost nothing to propulsion??

Quote:

Originally Posted by CharlesCouturier (Post 30317)
The leg kick does not contribute to propulsion in longer distance events, regardless of if it's swam in a pool or open water.

This is obviously not true, when stated as a general proposition.

CharlesCouturier 08-13-2012 05:33 PM

Quote:

Originally Posted by swim2Bfree (Post 30348)
This is obviously not true, when stated as a general proposition.

"The question here is whether the front-crawl swimmers should use it (the leg kick) for propulsion or simply as a stabilizer. Adrian, Singh and Karpovich (1966) have provided the most provocative information concerning this matter. They measured the oxygen consumption of 12 competitive swimmers while they were kicking only, pulling only and swimming the full stroke. They reported that swimmers used nearly four times more oxygen when kicking only than they did when pulling only. The oxygen requirement was 24.5L when they kicked at a speed of 3.5ft/sec, compared to a requirement of only 7L when they pulled at the same speed. These results are supported by the work of other researchers as well (Astrand 1978; Chrbonnier et al. 1975; Holmer 1974), all of whom found that kicking caused a considerable increase in the energy cost of swimming.

These data present a persuasive argment that **middle distance and distance swimmers* should reduce their kicking efforts to conserve energy during their races. The energy requirement of kicking is disproportionately large relative to the additional propulsion the legs can provide. Therefore, it seems advisable to reduce the effort from the legs to the minimum required for support and stabilization during middle distance and distance races. In doing so, swimmers will delay fatigue so that they can swim faster average pace the entire race."
(Ernest W. Maglischo, 2003)

If by General Statement you meant in the context of flat out sprinting effort, then I obviously agree that this statement may not apply.

swim2Bfree 08-13-2012 08:30 PM

Quote:

Originally Posted by CharlesCouturier (Post 30357)
If by General Statement you meant in the context of flat out sprinting effort, then I obviously agree that this statement may not apply.

No, I mean it's obviously not true when stated generally about distance swimmers. If it were, then all elite distance swimmers would use a light 2-beat kick for stabilization. Even a cursory observation of elite distance swimmers (both pool and open water) shows that some swimmers use 6-beat kicks that contribute materially to their propulsion, even at marathon distances.

Of course kicking increases the energy cost of swimming. But it doesn't increase the energy cost equally for all swimmers. Isn't that obvious? Human bodies are different. Some people are more energy-efficient kickers than others. Maglischo is saying that on average the propulsion provided by kicking is not worth the energy cost. He is not saying this is true for all swimmers. And he is certainly not saying that (as you stated) "The leg kick does not contribute to propulsion in longer distance events."

CharlesCouturier 08-13-2012 08:36 PM

Quote:

Originally Posted by swim2Bfree (Post 30364)
No, I mean it's obviously not true when stated generally about distance swimmers. If it were, then all elite distance swimmers would use a light 2-beat kick for stabilization. Even a cursory observation of elite distance swimmers (both pool and open water) shows that some swimmers use 6-beat kicks that contribute materially to their propulsion, even at marathon distances.

The only reason which forces d.swimmers to kick more than the ideal (which remains 2bk) is that the tremendous level of pressure put early into their pulling stroke breaks a balance that would otherwise be good enough for a 2bk.

Quote:

Originally Posted by swim2Bfree (Post 30364)
Of course kicking increases the energy cost of swimming. But it doesn't increase the energy cost equally for all swimmers. Isn't that obvious? Human bodies are different. Some people are more energy-efficient kickers than others. Maglischo is saying that on average the propulsion provided by kicking is not worth the energy cost. He is not saying this is true for all swimmers. And he is certainly not saying that (as you stated) "The leg kick does not contribute to propulsion in longer distance events."

Listen, I'm truly sorry that I shocked you with my statement. I'm even a bit surprised that you take it this way. The beauty, is that you're certainly not forced to believe in anything I, or anyone else is writing.

I definitely agree with both Maglischo and TI on this topic, as it's been what I've observed over the last 18years of coaching, ie most people having a sound pulling mechanics are literally faster when swimming long endurance sets with a pull buoy. It's as simple as that. Maglischo does clearly state, if you re-read his quote, that this recommendation applies to all, with no single exception.

Obviously though, these recommendations apply to those having a sound technique (Maglischo has observed elite swimmers, not age group or masters). There's a lot of data that suggest that several distance recreational swimmers are faster full stroke compared that with a pull, and that even over longer distances. My personal take though is that these swimmers would benefit in:
1. Improving their balance
2. Improving their pulling mechanics

Again though, you certainly don't have to believe me.

WFEGb 08-13-2012 11:22 PM

Hi Charles,

just a remark from an unknower: When I realize that a Marathon runner is running 42km in a 400m-pace that I could just run once in my fittest (long ago) years. I think at that level (some 10sec difference after a 10km swim) energy wastage more or less with a 6bk to get an additional "sprint drive" might just make these tiny differences, in cause of technique this wastage might not be put into the stroke itself.

That's nothing against Maglischo's energy statements.

Regards,
Werner


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