Elite vs. Masters in the open water

by Evan Morrison. 15 August 2010.

What’s the difference between Masters open-water races and elite FINA or USA-S open-water races? I would argue, it’s not so much the absolute swimming speeds (1:10 per 100m for 10K, compared to 1:20 to win almost any Masters 10K), but the variability of swimming speeds.

Masters races have a much wider spread of abilities. In this year’s USMS 10K at Morse Reservoir, the top 10 finishers were separated by 9 seconds per 100m, and the winner was a full 29 seconds per 100m faster than the median finisher. What this means is, most people are swimming most of the race by themselves.

In FINA races, the spread in abilities from top to bottom is (I would guess) less than 5 seconds per 100m. What that means is: lots of pack swimming. In order to successfully break away from an open-water peloton, a swimmer will not only have to swim faster than the others in the pack, but fast enough to break out of the peloton’s draft.

As a result, elite races are characterized by 8-9K of conservative, highly tactical swimming followed by 1-2K of balls-out sprinting. In contrast, Masters races - especially those over an hour (for the winner) - more closely resemble “time trials.”

As an exhibit, here are the 2K splits (with 100m paces) from the June 2010 USA-S 10K National Championship, provided by Powerhouse Timing:

**A Gemmell (M-3)
**J Kinderwater (M-6)
0:23:22.69 0:01:10.13 0:23:21.75 0:01:10.09
0:23:43.88 0:01:11.19 0:23:43.41 0:01:11.17
0:23:52.90 0:01:11.64 0:23:54.31 0:01:11.72
0:23:46.10 0:01:11.31 0:23:46.10 0:01:11.31
0:22:30.27 0:01:07.51 0:22:35.97 0:01:07.80
**C Sutton (F-1)
**C Jennings (F-2)
0:23:49.27 0:01:11.46 0:23:49.27 0:01:11.46
0:23:59.33 0:01:11.97 0:24:00.26 0:01:12.01
0:24:12.62 0:01:12.63 0:24:13.78 0:01:12.69
0:23:35.20 0:01:10.76 0:23:28.99 0:01:10.45
0:23:42.40 0:01:11.12 0:23:48.06 0:01:11.40

These were the only four swimmers for whom all 5 splits were recorded. For the men, Gemmell and Kinderwater finished 3-6 (negligibly behind the winner), and for the women, Sutton and Jennings finished 1-2. Interestingly, the splits were almost identical through 8K, for both men and women. In the last 2K, the men seemed to find a new gear - almost 4 seconds/100m faster - while the women maintained their previous pace.

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Posted in: analysis Tags: data , elite


On 2010-08-15 08:02:15, Sully said:
This is very true in cycling and running as well. It is such a science in cycling that in the Tour de France there are very accurate algorithms that can predict how long it will take the peloton to wheel in the attacker. You make an interesting point about the 8K splits being nearly identical. That data fits nicely when you look at yesterday's post and today's. There is still a fairly large gap between men and women in shorter races - if you can call a marathon short. But as the distance increases to 100 miles plus, the gap narrows. In fact women sometimes win the overall in ultra marathons. It seems women's speed may max out quicker, but their "hold forever" pace is very comparable to men.

On 2010-08-15 17:41:04, Evan said:
It's remarkable how similar those paces are between men & women. Another thing I noticed is that the difference between the men & women on the last 2K (~4 seconds per 100m) is quite similar to the difference between the fastest American men & women in the 1500m Free - approx. 1:00/100m for men and 1:04 for women. No doubt, the gender gap narrows (and perhaps eventually disappears) at ultra-marathon distances. Hence the dominance of Shelley Taylor-Smith at MIMS and Rondi Davies at Kingdom Swim. But I do think there's still a non-negligible gap at the 10K distance - for instance, I doubt Fabian & Sutton could keep up with Crippen & Peterson in a time trial setting. I think the reason the paces are so similar in open-water "pack" races is simply that the women are working harder. This has been noted anecdotally by Munatones, etc., though I don't have an explanation.