I'm not a sprinter by any means, but still went 47.5 in the 100 free and a 4:59 500 free in May at Masters nationals, and can push an 11 low. I also coasted a 27 low at 70.3 worlds in Chatt. My best IM swim was in Cda with a 51. I am not going a 44 min 2.4 mile swim without a LOT of swim training which ain't happening anytime soon.

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Strava

That pace is faster than my only recent 1650 pool race time, done on a consistent 10-13k yards/week training. Not necessarily long-distance specific training, but more of a multi-distance freestyle training for the gamut of 50-1650. I went 21:17. Same meet, I went :57.31 for 100 yards free. My eg.swim Rating, which scores your time based on your delta from the age group USMS National Record (SCY) or FINA Masters World Record (SCM/LCM), for both swims were almost the same (77.3 & 79.0), suggesting I'm roughly equal in ability at sprint and distance. I'm pretty much high 70's/low80's across the entire distance/course spectrum for freestyle.


The one time I did a two mile open water race (USMS 2 Mile Cable Swim National), I went 53 flat. My execution wasn't good, but even had I executed perfectly, I maybe would have gone 51-mid. Your formula, even with the conservative factors, says I should have gone 44:low. That would have been ~ 1.5 minutes behind Kurt Dickson, who's won the age group, was second overall, and finished the year ranked #1 in my age group in the Nation in the 1650 with a time that was over 4 minutes faster than my 1650. In other words, your formula is predicting my unremarkable sprint speed (I finished the season ranked 129th in the 100 free) to be an indicator that I should be an elite-for-my-age group distance swimmer.

The difference between me and your other 1:30/100 yard long distance swimmers is that I can briefly spin up to 180% of my long distance stroke rate and only forfeit ~20% DPS. But I'm not remarkable in that regard, they just don't know how to sprint.


Could I go faster in 1-2.4 mile open water races if I trained more for them? Sure, but I could probably go faster in the sprints if I trained an equal amount more for them, too.


I think you'd find more meaningful correlations between 200y pace and 2.4 mile pace.

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"They're made of latex, not nitroglycerin"

You're the lone swimmer who is really far out of line with the predictions thus far. Your 1650 25 yard splits (19.35) are over 150% of your all out 25. Most are closer to 130%, so you slow down nearly twice as much.

Either you really are a sprinter, your undetrained, or your stroke really falls apart.

So call it 11.2 for a 25 sprint?

11.2 x 4 x 1.04 = 46.5 Seems like that should be possible with moderate training, based on your own assessment? The faster you are, the more you will be using the entire +/- 4% range

Sounds like another swimmer within predicted range.

So you just magically turn a wet suited 51 to 46.5 and say it "fits" your model? In the process, you just turned sch340 into a contender for the all time, all age group, USMS 2 mile open water National Record (38:32). Congratulations.

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"They're made of latex, not nitroglycerin"

I have said about 12 times now that the model underestimates for faster swimmers. However, it does predict a 2.4 mile swim that is 2.5 minutes slower than the poster himself suggested would be possible with proper training. Also, the output is for a 2.4 mile open water swim, not an IM swim. Stand alone 2.4 miles should be quite a few minutes faster than a triathlon leg. I don't think I turned him into a contender, so much as I verified his contention that he could be. He's sub 5:00 in a 500 on less training than he is capable of. At least that was my takeaway. If he is also skilled in open water tactics, there are going to be very few feet that could shake him in a masters open water race.

I think you (and others) miss one big takeaway, which is if you want to break an hour in an Ironman swim, you better be at least knocking on the sub :15 / 25 yard door.

Finally, consider the formula to be a living thing. It's not even 2 days old. If you have something constructive to add, I'm open to hear it. If you just want to repeat that it is not perfect and inaccurate for fast sprinters, I get that. I do not think this is a fruitless exercise, as the more average triathletes who run their own math seems to confirm there is some utility here.

I won't argue with that, but here is the reason we choose 25. This formula is purposely geared towards mid pack adult onset swimmers, ie - swimmers who are actively seeking to make significant technical improvements.

"Masters athletes, and new to swim athletes in specific, often think about what kind of paces they can hold in training in terms of sets of 100s, sets of 200s, etc, with the goal to improve their time for swims that are greater than or equal to a mile in length. When seeking greater speeds in those sets they tend to ask what technical improvements they can make, and seek to make those improvements in the course of their workouts – doing 100s, 200s, etc. while “thinking about their stroke”.


But as you practice some new technique, your body is inevitably weak in terms of repeating that technique because it has not practiced it much. The technique will therefore tend to degrade as one swims 25, 50, 75+ yards continuously. In my experience, this degradation is so pronounced that much of the technique change that is desired disappears after roughly 50 yards, and the “new” stroke becomes unrecognizable after 100.


If we accept this as a truism for many athletes, shouldn’t we instead try to focus on how fast they can swim 25 yards at a pop? And to make us “stronger”, focus on how fast we can do 25 yards, and how many 25 yard repeats we can do? For some context, I wanted to look at just how fast one needs to be in an all out 25 in order to reach a given speed in a mile. "

Worked perfect for me - but I used 25m time - and not best but what I can maintain for 6 repeats. And I'm slow - and the water conditions for PR 3.8k were perfect. I'll use this in the future to establish targets.

My contention isn't just that it's inaccurate for "fast sprinters," it's that its inaccurate for anyone who even dabbles in sprints. You said in an earlier post:


That got me thinking. I will admit that my competency biases towards sprints. My actual best eg.swim Rating is in the 100M LC free (my mediocre turns are a liability in the short course 100, and my mediocre start a liability in the 50). But think I'm a fairly accurate representation of a "utility freestyler" who's reasonably competent across the spectrum of distances.

I went to the USMS event rankings and results data base, and looked at everyone in my age group who was +/- 1 minute of my 21:17 1650. Almost all of them had posted a recent 50 free time. The average of 15 times for SCY was 26.54. Rule of thumb for 25 splits on a 50 is the second 25 will be ~.5 seconds slower than the front half. The back half of a 50 also happens to essentially be the 25 wall push time you're asking for. So one could reasonably assume that these guys, on average, can do a 13-flat 25. That suggests my speed regression is a little more than the average, but not the huge outlier you suggest. Pretty much what I already knew.

If you're truly interested in creating a formula that tries to predict long distance speed capacity from sprint speed, my constructive criticism would be to start with accurate data. I think right now you have a "garbage in, garbage out" situation. You have estimates, sometimes with a half-second wide windows, of 25 sprint times. You have open water long distance times with all kinds of unknown variables (was the distance accurate, was there a current, was it a wet-suit swim, was it salt or fresh water, etc.) The USMS website is a treasure trove of data. In the results section, you can look up an individual swimmer and get a list of every pool swim they've done in the last 10 years. Look at the 1650 results from USMS Nationals, then plug those swimmers in and see what they can do for a 50. Once you have an accurate model for that, you can start figuring out a conversion factor from a 1650 pool swim to a (pick your distance) open water swim.

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"They're made of latex, not nitroglycerin"

I won't dispute anything you said. I am trying to come up with a simple formula for the abundant adult onset triathlon swimmers who are anywhere from back of the FOP to back of the MOP, maybe an hour to 1:25.00 or so. I would like to provide them a very easy range to shoot for, based off a 25 yard sprint, as that keeps it simple and recognizes the difficulty in holding form while in the midst of technique changes.

Based on feedback so far, 4X (+/-4%) seems to do that very well. I would say it predicts a non wetsuit stand alone swim fairly accurately, and therefor slightly overestimates a (properly navigated, thoroughly trained, and accurately measured) IM swim split in a wetsuit.

An additional caveat I am considering is that the 25 sprint should be done with the 2.4 mile breathing pattern, as the extent to which the act of breathing disrupts propulsion can be fairly significant in adult onsets.

I do look at the USS and USMS data pretty often, but in this case, I think their data would skew the formula away from the target athletes.

What do you think?

no way.... too much fast water in an IM swim, especially the mass start ones.

Depending on the IM, my wetsuit and non-wetsuit times are the same because the non-wetsuit swim is a larger mass start one with lots of good swimmers to draft.

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Eric Reid AeroFit | Instagram Portfolio
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“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

I get that, but you're awesome, and awesome athletes skew this formula that is directed towards entirely unawesome swimmers. You are a bit under a hour and likely highly skilled at drafting, right? Plus wet suits don't save as much time for faster swimmers.

as an adult onset swimmer there's no way I'm awesome, but yes, 58:50 at Kona vs. a 58:30 at CdA same year 2013. Perhaps your +/- 4% is a two-factor fudge... some sprinter vs. endurance and some drafter vs. non-drafter.

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Eric Reid AeroFit | Instagram Portfolio
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“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

I'm definitely going for simplicity, so there will be some inherent error. The real question is, what's YOUR 25 yard sprint? If it's between 14.0 and 15.5, I'm calling 4X (+/-4%) accurate enough.

Not sure, but I've hit 30" for 50scy so call it what, 14? 13? If so I'm underperforming as compared to your model.

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Eric Reid AeroFit | Instagram Portfolio
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“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Maybe a 14, probably not a 13. 14 x 4 is a 56 flat. If we apply the entire 4% range we get 58:15, which is pretty close to both of your posted times. If you can hit a 13, you'd be underperforming, but 13 from a push would almost always translate to much faster than a :30 / 50 yard.

When are you getting in the pool next?

25scy sprint 13s
500scy about 6:50-7min

best (only) HIM time several years ago, 33 low, on 2-3k weekly..

a 5k time is an excellent predictor of marathon time, if you are doing marathon training.. probably a similar principle applies here, on my (now) 4-6k weekly, the 25yd time doesn't predict much.

I'll try a 25 tomorrow

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Eric Reid AeroFit | Instagram Portfolio
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“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Indeed. Basically shows you need to train more if you want to translate more of that speed to longer swims. You are over 60% slower than your sprint time at the 500 yard mark. (13s vs 21s) Huge speed degradation there.

I would put another caveat that they have to use the same kick pattern.

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"They're made of latex, not nitroglycerin"

Rather than saying it "under-estimates" for faster sprinters, I think you should just say that your formula is only valid for true D swimmers, who have a slow fall-off in pace as they go from 100 to 200 to 400 m/500 yd to 800 m/1000 yd to 1500 m/1650 yd. Further, it is only valid for true D swimmers who are in top swimming shape.

The queen of D swimmers on ST is tigerchik, or Dr. tigerchik as she is called now after getting her doctorate. Dr. TC swears that her best time for 100 yd is 1:07 but yet she has gone 19:47 for the 1650, which is about 1:12/100 yd. That is the lowest rate of fall-off I have ever heard of. :)

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"Anyone can be who they want to be IF they have the HUNGER and the DRIVE."

I am not sure it is so far off for decent but not exceptional sprinters (with the caveats edited into the OP). It seems to do a decent job with Mr Reid a few posts up.

If you can sprint an 11, it gives you 45:45 for a 2.4 miles on the high end. Probably a little quick. At 11.5, it's 47 high, and at 12 flat the high prediction is close to 50:00. Not too far off. It seems to do well in the :13 - :25 range. On the slow end, to make the 2:20:00 cut off, 'requires' a :35 or better 25 yard sprint.

And then off course I have John Kenny on Facebook claiming he swam a sub 31:00 / 2.4 miles (11.0 / 25) but can only sprint a 12.5 / 25 yards. See, math isn't just hard for me!

Well, I know John is a great D swimmer but 11.0/25 yd implies 1:28/200 yd which is faster than the 200 yd AR of 1:30.X. IIRC, John has gone around 16:30 for the 1650, or 15 sec per 25, so I would think he could do 11.5-ish for a single 25 yd. OTOH, he was best at the 25K distance, so he is truly an "ultra-diesel". :)

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"Anyone can be who they want to be IF they have the HUNGER and the DRIVE."

This. I can pop off a 25SCY in 13-14 seconds but there isn’t a chance in hell it would get me a 52 minute 2.4. Even at my most trained up state I couldn’t pull this time off and I was swimming a 0:54.0 100SCY. The line needs to curve.

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Hillary Trout
San Luis Obispo, CA

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Well, maybe that, but how bout this....First, there's a big difference between 13 or 14. Go sprint a 25 with your endurance breathing pattern and report back. Whether you go 13 or 14, I'd expect you to be on the high end of the range. 54 low to to 58:15 would be the predicted times. I wouldn't expect you to go 52, and I've mentioned this about 14 times now.

The line needs to curve if I am trying to be hyper precise or predict Rowdy Gaines's IM split, but I'm not. I'm trying to give the fat part of the bell curve age groupers a reasonable range based on a quick and easy assessment of their speed. Feedback thus far indicates success.