Too slow for me. But also haven’t done an all out 25 in a while. Put in 16 seconds and it came out with 63 minutes for me. Last IM I did I swam a 59 and I better be faster than that now!

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I predict a 15 flat 25 yard sprint.

My PB for a 50 free (masters) is 25.9 (SCM) That equates to about a 13.7s 25m free from the push (add .75 seconds to compensate for the a 1.5 second benefit off the start)

Converted to yards, that's about a 12.45 25 yard time, which, according to your calculator, means I should be in the range of 47:35 to 50:30 for an IM swim.

I haven't done an IM yet. Give you a half IM time next year....

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Sounds reasonable. I was a little faster than that in my swimming days, about 25.5 LCM (low 22 SCY), and literally loafed to a 52 minute swim on the IM Lake Pllacid course with about that same fitness. I backstroked a lot of it, waiting for others. I 'think' I could have swam it in 45 or so, and I also think I could have went about 11.5 for 25 from a push.

Can I divide by 2 for my 70.3 split?

I can do a 25 with 1 or no breaths to hit a fast time. But if I do the 25 breathing every right stroke (like I would in a 70.3), my 25 time is slower. Is the latter the better predictor?

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Strava

My 50m free time is almost the same as Jason - 26.02 (*shakes fist at Jason*). My IM time is 54:03 (albeit 5 years ago in somewhat less swim form but not massively so). Going sub 50 for an IM seems out of reach to me. Maybe I'm under estimating what I could have done on that 26.0 fitness.

Close only counts in horseshoes and hand grenades.... ;-P

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100 free is even worse (if the masters canada site is right). 0.01 difference there

A couple points:

1. I'd estimate you need 20k weekly yardage to get close to the prediction. Wide range there, but more swimming than most are doing.

2. While my equation is linear, the relationship of 25 yard sprint to IM swim spits is probably not linear, when we consider a wide range of sprint speeds. It definitely underestimates IM Splits for very fast sprinters.

Something like Slowman's quadratic equation for predicted armrest drop is what is needed. That equation is C=.005D² - .2D (C = drop and D = seat height) But that is only good at 77.5° of seat tube angle. At steeper angles we need to predict greater drop, and shallower angles generally result in less drop. So that .2 before the final D gets bigger (for shallower) or smaller (for steeper) by .0075 for every degree we deviate from 77.5°

I likely need to anchor my formula at perhaps a :15 / 25 yard sprint predicting a low 59 IM swim, and then modify the calculations slightly for faster and slower sprint speeds. Or maybe a :16 / 25 yard predicting a 1:03 swim is the right starting point? It was just something I whipped up while basting a turkey, so any math majors want to take a shot at this, feel free.

It does seem to work well in the 14 - 24 second range

That's OK, you've got me in the breaststroke events. Not that anyone cares about breaststroke, the red headed stepchild of swimming.....

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Like zenmaster, I "think" that's an overly aggressive estimate of what I could actually do. My most recent 1500 swim was a 19:36, granted I'm not in really good swim shape right now, only getting in 3000-6000m per week, but I'm guessing that if I was in the same shape I was when I swam a 2:04 and 4:32 for my 200 and 400 (both SCM) then I'd be able to do the 1500 in 18:30-18:45 or so... If I could continue at that same pace, that's a 47:30 for 2400m in the pool, with a lot of turns....

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I guess a difference is do you calculate this with a push off or off the blocks? I’m sure that makes a difference too. Either way kind of a cool tool. I remember someone saying a 17 flat 25 meant you had the technique for an hour IM swim so the calculator matches with that at least!

My 70.3 swims range from 26-30 the last few seasons depending on conditions and course accuracy so I’d hope next IM I’m closer to mid 50s. But still have work to do!

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I'm assuming its with a push. If we were to use my (estimated) 25 yard time off the blocks to my feet, then the model has me at 43:41 for an IM swim, and slightly faster than that if it's to a hand touch.

I don't think I'm that good.....

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We're just having some fun here. At least I am. I've got a bunch of coaches telling me it's way off, worthless, ridiculous, whatever.

I think a lot of you guys are missing the point. I am not trying to predict Cesar Cielo's IM split. I AM trying to help the average age grouper who might sprint at :19.0 / 25 yards, but then lays down a 1:30.00 IM split. There are plenty of those swimmers, and they would do well to question that 25 yard to 3800m relationship. Maybe they find out that a properly structured swim program of 15-20k weekly is NOT such a waste of time as they have been led to believe. Or their navigation sucks. Or there is some low hanging fruit somewhere and they should try to find it.

Same as 220 minus age is max HR...

No I get that. I'm really not a sprinter, either. My sprint sucks compared to middle d.

just giving you a bit of data that you might be able to use to tweak the model, whether it's the coefficient, the error boundaries, or what have you...

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pk wrote:

Same as 220 minus age is max HR...

World class coaches are a fragile group.

I didn't mean you Jason. You're a helpful dude.

Oh I totally get it! ANY predictor is just an educated guess assuming proper training. I love these calculators because they give a range/idea of what might be possible. This is similar to using a 1 mile/5k race to predict a marathon. It might do a good job in an ideal work but, like you said, poor sighting, poorly measure course, not finding feet, etc. can dramatically change the race. It is just another fun tool everyone can use to drive themselves crazy with more data points!

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You're hired!

More like trying to predict a half marathon time from somebody's 100 meter dash time.

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The funny thing is, it's proving to be pretty accurate, whereas the same would probably not hold true for your 100 meter dash / marathon metaphor. Why do you think that might be?

 

IMMT swim this year was 1:05:xx

Did a sprint set the other day(SCM) and was trying to keep them all at 16s, fastest one was 15.7

So would that put an all out sprint around 14.5? I'm just guessing. I have no swim expertise.

That puts the equation time at 57:xx, that's with no handicap for SCY/M

Do I think I could do that, yeah. I think I could do that. But when looking at a race scenario, not a chance am I going to push that pace. I would be so bagged after that, no sense in even getting on the bike.

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For a 25 yd sprint (yards being the key here), you need a 15.2 for the 25 yd sprint to go 59:59. Or were you thinking 25 m with the 17???

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It was kind of agressive to me. Not much, but a bit.
Divide that number by 2 and that's my HIM split with good accuracy but I obviously don't swim IM = 2xHIM.

I should probably change the thread title to 2.4 mile swim time predictor, as that is what is really being predicted. IM swims should be slower of course.

A really good question, and ultimately something that could add to the error due to the very simple math involved. The constant 3.94 was derived from 25 sprint estimates which would involve little or no breathing. If your breathing disrupts your propulsion to a greater degree, than you could either add some time to the estimate or, as you suggest, sprint a 25 with your long course breathing pattern.

We were doing sprints last night in my masters session. I don't like sprints. I am very definitely a slow twitch athlete. Off a wall push (fatigued, end of session) I got a 33s 50m. Could probably trouble sub 30s for a 50m off a block dive and fresh - the guy who I was chasing in the next lane last night swam a 26.5s 50m at the nationals a few weeks back.

I have an Ironman swim pb of 54 mins, and haven't swum a pure 2.4 mile TT to compare this with.

Using your calculator, and doing some rudimetary adjustment to take yards from metres it gives:

50m = 54.68 yards
Using metres, your calculator gives a time of 65:01 for the IM swim
To convert this to yards I took 0.91% which is what you get if you do 50 (metres) / 54.68 (yards)
65:01 x 0.91 Gives around about 59 mins 27s

About 5 mins off my IM pb, and I am currently swimming some 30s per 400m faster than when I set that, so reckon I would give 50 mins a good go at present if I were to go at it as a flat out effort.

I think your attempt at using this as an estimation is inherently flawed. The bloke above is a sprint monster - he goes around 26 for a 50m free. Put him in a 3.8km race though and I would swim circles around him. He has no endurance just as I have no speed. An elite age group sprinter might swim 25 seconds or so at a masters event for a 50m free, but it doesn't necessarily translate into endurance.

If you swim 30s for a SCM 50 from a dive, you're about 27 for the same in yards. A 27.0 50 yard free will be split in the ballpark of :12 / :15, which puts your 25 yard sprint from a push at maybe 14.0-14.5. Call it 14.25 and we come pretty close to your actual IM split.


You're a better argument for 3.94 giving reasonable estimates, not inherently flawed.

can you recalibrate it for metres?

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But I am a slowtwitch diesel engine. I think that the problem still stands for the sprinters amongst us. The guy I mentioned for instance who can go around 26s for the 50m free has a 200m free split in the region of 3 minutes. He just absolutely sucks at anything longer than 100m.

I guess the point I am trying to make is if Usain Bolt were to run a marathon, what do you reckon he would do? A similar calculator might put him sub 2 hours, but we can safely say he wouldn't be anywhere near that - he might not finish the thing!

My point is, I think you can sprint close to a 14.0 / 25 yards, which predicts a low 55. 3% faster is a mid 53, 3% slower is a high 56. So for your current IM PR, we nailed it.

I have already stated that for super fast swimmers, it will tend to underestimate. I have also stated that:

"if you are physiologically suited for the a 15-20 minute event, and trained to the limit of your endurance capabilities, then you should be able to average approximately 130% per 25 of your all out 25 sprint time, and you can do 140% per 25 in a multi-mile swim"

So the point I would make is that it is easier to predict a long distance swim from a 25 yard sprint, than to predict a marathon performance from a 100 meter run. And I just showed it. Sprint swimming and endurance swimming have more in common than sprint / endurance running.

With you. Carry on. I've had a few beers and maybe didn't get the gist of the thread.

No worries. It a simple relationship I derived just yesterday, so it ain't perfect and there are limitations of course. Same with heart rate training and Daniels VDOT. Understanding both the limits and potential is the key to all of these.

If you know your 25 meter sprint from a push time, I'd just take 91% of that for your 25 yard time, and then apply the 3.94 Hell, you could just round it to 4. It's not an exact science.

Does your sample include any actual sprinters? Or is it just long course triathletes who never actually train for sprints? The projections just seem wildly optimistic to me, someone who has one foot firmly in the Masters pool swimming world but who also dabbles in open water and triathlon. I can do a 12.79 25 yard free, off the wall. I'm a pretty unremarkable sprinter; there are over a hundred guys in my age group Nationally who are faster sprinters than me. But your formula suggests I should be able to keep pace with, or be slightly ahead of, the small group of guys in my age group who are contenders for the USMS National Championships in the 1000/1650/1 mile open water/2mile open water/2.4 mile open water events.

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"They're made of latex, not nitroglycerin"

I can swim 13-13.5 or so from a push. I have never done an IM but swim 20 minutes in an open water 1500m. I am a runner by trade and my stroke falls apart with longer distances unless I am swimming at least 15 to 20k a week.

Your 12.79 / 25 yard sprint predicts a 2.4 mile swim split of mid 50:xx Call it a 50:30 (3% slower is roughly 52 flat. 3% faster is roughly 49 flat) As I said, the faster you go the more it tends to underestimate, so if we give you a 5% range, on the high end you're looking at a 53 flat. Are you saying you could not do that if you were well trained for it?

My original sample was done by estimating the speed degradation of excellent distance swimmers. I calculated their 25 yard splits in a mile swim being 130% of their estimated 25 yard sprint speed, and used 140% for their 2 mile+ 25 yard pace.

I'll use13.25 and simplify my constant to 4 (instead of 3.94), giving a 2.4 mile time of 53 flat. So roughly 22:00 per mile. (+/-3%)

If you are 20:00 for an open water 1500, you are ballpark 21:30 for an actual mile (1609m) So 22:00 per mile for 2.4 miles may be a bit optimistic, but well within the +/- 3% range.

Next?

15 sec 25 yards comes to a :59 IM
My best IM is 1:04.

I wish this was accurate for me!!

Well, not too far off. I think I will make it simpler and just use a coefficient of 4 instead of 3.94 So your :15 seconds sprint comes to 60 minutes, 3% slower is a high 61:xx. How much did you train to hit that 1:04? How straight did you swim? How hard did you push?

I see a reasonably local opportunity to collect some data towards validating or adjusting the model.

2018 U.S. Masters Swimming Open Water National Championships

USMS Middle Distance Open Water National Championship (2 miles)
Reston, Virginia, May 27, 2018

I was in good swim shape which isn't saying much.

It was at placid and I followed the cable.

My stroke goes to crap after about :30minutes.

I just joined a masters group and I hope this gets me motivated to go under 1:04.

I was expanding on my earlier post where I said I was about 16 the last time I tried a 25 but have swam a 59 in an IM swim. I am not sure what my 25 time would be now but I THINK I can get a mid 50's IM swim now, or I hope so! But that all depends on the course, conditions, and if I can find a group. But Jonnyo is killing me in the pool so I trust I will get where he wants me to be!

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There was a thread recently where a guy was saying he had done a 50+/52/53 for his ironman swims. And based on his pool 400/1000 it seemed as if he was swimming too fast for those IM swims, but then I drilled down a bit. Those are all wetsuit swims, as I presume are all the IM times people are giving you here. When I pointed this out he said oh ya, by the way I did a 57+ at Kona..SO that made a lot more sense in his predictors, I think your formula is having the same problem, only in reverse. If guys here were actually giving you Kona or Florida swim times(without rubber on) the formula would be much further off on the pointy end.

I think you have a good start, but somewhere under 16 seconds it has to be adjusted or you will have everyone swimming sub 50 IM swims without wetsuits. You know how hard and rare that is, especially to the average AG swimmer who can easily push a 13+ 25yd.

And your assumption that IM swims are slower given a pretty close distance is really off when you figure in the wetsuit and the drafting. Sure you back out turns, but that is not enough to negate the other two things, and if salt water, well that is another huge plus for swimming faster times It's too bad that virtually no one here or elsewhere actually swims an IM swim in the pool, that would be an interesting comparison if there were enough data. Best you could hope for is a 25 sprint vs maybe a 1000 time predictor? Drill that one down to a small +/- and you wont be that far off of getting a good 4k predictor. And lots if not everyone has done a 1000 for time, or could if they wanted to see where they stacked up in your formula..

Continue on, just my 2 cents.

Spot on.

I can do 19sec 25scy on wall push, your prediction of a 76min 3800m swim would be close (not counting currents, chop etc) based on my 103 minute 5200m cross lake swim (completed on ~5K/week for 2 months training).

People who swim 90minutes for 3800m despite being able to do a 19 sec SCY likely have poor technique and/or poor swim endurance but lots of upper body power to muscle through a short distance. I have no upper body strength, but good enough technique and good swim endurance.

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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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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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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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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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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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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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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

Your trip is short. Make the most of it.
https://www.slogoing.net/

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.

I've read through this thread at different times over different days and tried to compare to my own swimming experience. The caveat here is that I am a pool swimmer since childhood. I'm interested in your assumptions about adult-onset swimmers (sounds like a disease to me) and what they do that is remarkably different than those who swam as kids. Are you basing this on increased fatigue, poor form, lack of feel for the water, all of the above, something else? I do have some issue with comparing an anaerobic sprint to an aerobic distance event. Are you assuming that all adult-onset swimmers process 25s aerobically? I currently train for the 70.3 distance so have no real data about my 25 yard sprint from push time. I'm 26:00 HIM distance swimmer. How does that back out to a 25?

Ya, but you are hardly the "average AG swimmer" if you going 54.0 for 100 yd, espec given your being a girl. When you were going 54.0, what were your 500, 1000, and/or 1650 like time-wise??? A good D swimmer with a 54.0 100 would go around 10:45-10:50 for the 1000 when rested. Just guessing but I suspect that you were/are a better sprinter than a D swimmer. :)

I had thought of responding to monty earlier on this but the "average AG swimmer" can NOT do a 13.X for 25 yd; your average Masters swimmer sure but NOT your average tri swimmer. The average tri AG swimmer would be around 25 sec as a guesstimate, maybe even 28-29 sec. Lots of tri AGers can not swim much faster for one 25 than they go per 25 for 1000 or 1650 yd.

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

So true. I know I could go sub-11 on 1,000 but never competed at the longer distances. Longest I ever competed was the 500 and that was a 5 minute hate session (my coach let me have my tirade and never did that to me again). And, for what it’s worth, the sprints use a ton of heavy powerful kicking where a 2.4 open water (especially in neoprene) is often a leg dragger. If I really put an all out 25 sprint down with somebody on a stopwatch or timing pad (off the wall) I’m sure I could squeak out a 12.x (today) but it just wouldn’t translate to the 50-60 minute 2.4. But now a days I don’t hardly bother to train for the swim because my training time will have more bang for the buck on the run. That’s the thing about growing up a swimmer. The land is the enemy and moving across land is quite difficult.

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Hillary Trout
San Luis Obispo, CA

Your trip is short. Make the most of it.
https://www.slogoing.net/

Certainly I can see how you'd want to concentrate on your run but, OTOH, if you swam 20K/wk, you could prob lead ALL AG women OOTW, not to mention 99.5% of the men, which would be pretty cool IMO, espec if the race were a mass start. Personally, I can run decently and should prob spend more time on the bike but I just hate not swimming. I still swim 7 days/wk and average around 25,000 yd/wk. I only race Oly dist and sprints so the swim is a little more important IF the course is semi-accurate.

Also, JOOC, do you remember your 500 time, and what was your best 200 yd free???

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

Assuming a 54:00 IM swim, that would put you at 54/4 = 13.5 sec. Can't speak for Dave on your various questions but one thing he has emphasized, and that I have observed over the years, is that many AG swimmers could swim an IM swim consid faster if they simply swam more. I think this is the main point of his deriving this equation is to show non-swimmers their IM swim potential based on their best 25 yd sprint in the pool.

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

so I did some 25scy sprints... 14.5 seconds from a push. I've not been swimming lately.

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“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.”

Yeah, that.

As to the difference between adult onset swimmers and those who swam as kids, it's similar to the differences we see when those same groups try to learn a foreign language or musical instrument. If you put English speaking young kids and their parents in a Spanish speaking house, in a few months the kids are going to be picking up the language, where in a few years the parents are still asking the kids how to say "pass the salt".

We see this mental plasticity delta in different age groups of swimmers pretty clearly when learning kick timing. In highly proficient swimmers the finish of each arm pull is nearly always timed with a kicking down-beat by the leg on the same side (i.e., left arm finish, left leg downbeat). We refer to this as "Finish-Kick" timing.

This timing is so ubiquitous in elite swimming, that it is regarded by Maglischo's book on swimming technique as "seldom a problem" (Maglischo, revised edition 2003). However, it is important to note that Maglischo's work was based overwhelmingly with national caliber collegiate swimmers and above -- in non-elite swimmers, the inability to produce this timing is as omnipresent as the ability is in their elite counterparts.

Kid's bodies figure out kick timing. Adult's bodies largely do not, and require a process by which awareness and control are developed.

Check out the video of the "backwards brain bicycle". I think this is very similar to the problems adults have in learning to swim.
https://www.youtube.com/watch?v=MFzDaBzBlL0

I'm right around 18" from the push, and I'm probably your target audience. My only comparison is 1650y at meet that I did at 90% in just under 25' (25yd pool). Calculator predicts 25.3'. It's not open water (walls), but no wetsuit, so close enough? 24' would be doable, but not 23' yet. Maybe this spring I'll revisit this before the meet.
Yeah, I don't really get why this works, but empirical fits are wonderfully useful things.

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Life is tough. But it's tougher when you're stupid. -John Wayne

Yes, it would be cool to be first out of the water, and when I was in college this happened a couple of times (when I had absolutely no clue how to race a triathlon - I literally changed my clothes in the bathroom in both T1 and T2, because... outfits!). But, the cool factor evaporates amazingly fast when you get passed by almost everybody on the run.

These are my placings in my last two races of substances (where there was real competition, not a little local race). On almost no swim training (maybe 2-3x 30 minute swims per month) I'm always top 1/3rd and usually top 1/3 on the bike (for gender). Then, everybody runs past me. Yes, I could put in the 20k/wk and get to the top, but my run is pathetic and I know with the right focus I can at least get to the top 50% of the field.

For my 200 my PR was 1:56.87 and 500 was 5:13.18. Once upon a time. P.S. I hate the black line and now really only do OWS anymore.

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Hillary Trout
San Luis Obispo, CA

Your trip is short. Make the most of it.
https://www.slogoing.net/

Thank you for the post. I've been racing triathlon for about 7 years but just started taking the swim portion seriously the last 12 months. By "serious" I mean going to the pool with a purpose swimming 10-15/week. My last 2.4m swim was in 2016 1:18 and a 1.2m swim of 36:50. After a year of consistent swimming and working on mechanics I recently swam 33:06 (2200 yards) HIM this past September which I was really excited about. Sunday I did a few dozen 25's all around :18 with a bunch of :17's in there. My fastest 25 yard from a push off is 15.9 and that was a few months back. I'm racing an IM in 2018 and would be elated with a 1:04. Any feedback would be appreciated.

So I did a few more long rest 25's at the end of my workout this afternoon. Using the same breathing pattern I'd use as my long distance pace (1 every cycle), but a strong 6 beat kick, I was coming in 14.low-14.mid. (FWIW, that's the pattern I would use for a 200 free race). When I backed the kick down to a 2-beat, like I'd actually use in a long distance race, I went 15.20, +/- .10. Just to verify that those times weren't overly fatigue-influenced, I did one no-breath, high-energy-kick, maximum-effort 25 at the end. Went :12.85, right in line with expectations.

So, with both the breathing and the kick pattern caveats, my 53:00 2.0 mile, and pair of 31:low 1.2 mile races (all fresh water, no wetsuit) suddenly fall right in line wih your formula. I just wouldn't call what I was doing tonight, other than the very last effort, "sprinting." ;)

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"They're made of latex, not nitroglycerin"

Well, I grasp your problem better now. Have you considered aqua-bike??? (semi-pink) You may just not be a runner, but that's not the end of the world. You are clearly a real swimmer though, and real swimmers are generally not good runners; if it were otherwise, triathlon would be utterly dominated by swimmers rather than only kinda, sorta dominated by swimmers as it is now. Take pride in your fish pedigree. :)

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

I was going to ask if this is me...I can do ~18 second 25 yd sprint. My Lake Placid IM was 1:20 -- I am pretty off here. Now is that because I can muscle through 25 yds? Likely. My 50 yd time is about 43 seconds so clearly a sharp drop off.

True that! The struggle is real. Priority 1 for me is to lose 25 pounds (see Race Weight Challenge threads). Those excess pounds are great for OWS, not so great for hauling my fat ass up a hill or running. From there, some speed work on the land. I'm young. I have some time ahead of me. And I used to be race weight, so I just have to get back there.

Thanks for the fishie kudos. Swimming is the easy part for me. Staring at the black line for yet another lifetime.... not so much. :-P

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Hillary Trout
San Luis Obispo, CA

Your trip is short. Make the most of it.
https://www.slogoing.net/