Swim metrics to predict an IM swim time
So I see tables/graphs and websites that will allow you to "predict" what your bike split and run split could be for your IM based off of certain metrics that you can test. Examples are Vdot for running and bestbikesplit.com. Granted, "predictions" can quickly fly out the window on race day given environmental conditions and nutrition plan execution (or lack thereof), illness, injury, equipment/wardrobe malfunctions, other athletes, etc. However, these types of predictions usually make the assumption that it's a gumdrops, lollipops and unicorns kind of day and these variables are omitted from the equation and prediction.
Is there something like this for the swim? Meaning, is there a metric that can "predict" what your swim time will be for the IM? I am able to do "X" in training or the test so therefore the prediction is that you'll do a "Y" swim split on race day. Is it the 1K time trial? Is there a table/graph or website that allows you to input data (or lookup data of others like pros, AG athletes, etc) and then do a comparison? Is the 1K time trial an accurate prediction/metric to use or is there something else? Just curious to see what the team has seen/used since I'm still new to the IM distance.
Thanks!
Comments
EN uses the 1K time trial to get your T-Pace that you'll use for interval training throughout the training plan.
IMO, no different from using the FTP test for the bike or the 5K vDOT test for the run.
All that does is gets you a basis from which to target workouts. A 1K swim, 20 or 40 min FTP test, or a 5K run test in no way are a predictor of how you're going to swim 2.4 miles, bike 112 miles, or run 26.2 miles. For example, I can hold a 1:30/100m pace for a 1000m test. That's like a 57-58 minute IM swim pace. If I tried to swim a 57 minute IM I would probably die in the water before I finished or if by some miracle I finished, I would not be able to ride my bike.
Race rehearsals for the swim and bike are a much more accurate predictor since you're doing the distance (or close to the distance). None of us are doing a 26 mile training run so you just need to trust the plan and your fitness for that one.
(Doing a quick bit of swimming time jujitsu, my 4.7 factor predicts Bob would swim about a 1:03, but he did 1:11 at his most recent IM...perhaps he is a little bit of a better time trialer than average.)
This summer I've been able to do a lot of LCM swimming, and I agree with Rich that I expect to swim pretty close to what I will pull 3800 LCM...using a buoy in the pool and wetsuit in the race.
+1. Although when I reviewed the spreadsheet comparing swim 1000 TT times to race results, I kinda eyeballed 0.93 +/- 0.07 as the "discount". And I've been doing pull buoy RRs in the pool for years, with very close approximations to race day results (with a wetsuit).
So even a RR in wetsuit ...even open water RR will be only a very rough estimate.
And, if your like me and get a surprising swim PR you'll get tangled up getting wetsuit off and loose all that time you saved anyway LOL
My 3.8 km with buoy is 88 mins while my 3.8 km in wetsuit is 79 mins — they were both in the pool and within 3 weeks of each other.
I suppose it is because my swimming sucks big time.
I am not sure what to make of this, because I think of my self as a 1:15 IM swimmer. When I do a 1000 SCY TT, I'm working pretty hard and I know I'm one of the "over performers" (in other words, I have to multiply by more than 4.7 to get my IM time). Maybe this is because I was a (bad) competitive swimmer when younger and I stilll can muster that mentality for the time required for only 1000 SCY. But today, I was just cruising. Not meandering, but just swimming at what felt like IM race effort.
Either I'm going to do a little better at the swim this year, or I suck even more as an Open Water swimmer than I do as a pool swimmer. :-)
Interesting article on ST the other day by none other than mr Dan "Bet You Didn't Know I Actually Swam" Empfield re swimming and performance times specific to Kona. The full article is here: www.slowtwitch.com/Training/Swimming/Swim_nomenclature_j4539.html
Here's the excerpt:
"It seems to be fair to say that you add about 7 minutes to your Ironman swim time for every 10sec that you add to your leave interval (there was a Slowtwitch reader forum thread debating this). So, if 50min is fair guess for a Kona swimmer leaving in the 1:10 lane (SCY), then if you swim in the 1:20 lane you're roughly a 57min swimmer in Kona. If you leave in the 1:30 lane you're a 1:05 Kona swimmer. If the 1:40 lane you're a 1:12 swimmer. If the 1:50 lane a 1:20 swimmer, if you leave on the 2min you're a 1:25 to 1:30 swimmer. If you leave on the 2:20, repeating your 100s on the 2:20, maybe you're a 1:40 to 1:45 swimmer. If you leave on the 2:30 you're close to a 2-hour swimmer. If you leave on the 2:40 you're in danger of not making the swim cut-off in an Ironman.
This is helpful, I think, because if you swim 10x100yd and you "can't make the interval" leaving on the 2:40 base, you have work to do. However, if you do that work, and you can comfortably make the 2:20 base then you should have no trouble making the swim cut-off if you can translate your swim speed in the pool to the open water."
This baseline review is appealing to me because we do a 10x100 TT in the pool to set your swim T-Pace, and if you could also use that to "predict" or "ballpark" an IM swim time I bet folks would be pretty darn happy.
So I typically would leave on 1:35 as I swim 100s on about 1:27/28 pretty comfortably. And I swam a 1:03:xx in Tremblant.
Anyone else have input here? Start a google form?
In 09, I swam 1:18.3X @ Kona and 1:10.3X @ IM AZ in a wetsuit. Both were fairly *easy* swims is calm conditions. Example workouts from that era include (all are 25 yds or meter pools):
12 x 100 meters on 10 s rest @ 1:42 (discount 10% for yds, results in a send off interval of 1:42)
20 x 100 yards ; 8 on 1:50, 8 on 1:45, 4 on 1:40, progressing from 1:34 >> 1:33 >> 1:31
Those were my two best workouts of this genre. More typical were :
100s on 1:55 (yds); several workouts of 12, 16, and 20 intervals.
Eyeballing all that, I guess I routinely would have been able to handle a 10 x 100 yd set on a send off interval of 1:45, +/-. Which means I *should* have swum 1:16 @ Kona. So according to him, I underachieved on race day. But certainly, the rough and ready formula is in the ball park. As usual, your fitness is tempered by your race execution.
It's the interesting the note the difference between what have here as two methods of describing a set:
The later is how we do it here, at least how I write the workouts. My feeling is that you're getting a bit more / consistent rest interval and therefore potentially swimming a bit faster and/or with better form for each interval.
The former is how "real" swimmers do it, how I grew up. It's creates some interesting dynamics:
Looking back at how I trained, I often wonder how different things would have been if we had trained, back in the day, using the guaranteed rest method.
The classic set for a D3 swimmer, like me, was say 20 x 100 on the 1:10 (SCY). I could do that literally all day. In fact, to add some challenge to it we would probably do it as descend 1-5, where we might go 1:07, 1:05, 1:03, 1:00, :58 for a set of 5, then go back to 1:07, etc. This teaches you very, very fine pacing skills, etc.
And the method of making a set harder was to reduce the rest interval. And so a progression across a season, for me, might look something like this (and these are totally budget, simple sets, just as examples):
And so I look back and wonder how things would have been different if, back then, the method of making the set harder was to structure more rest to yield faster swimming. IOW, how would things have been different if we were doing 100's on the 1:30...but essentially racing them, shooting for :55's on every one?
^This^ is what I'm trying to achieve with that go-to set you guys see a lot: 20 x 100, as 50 hard, 50 easy. I want you to swim very fast for a 50...then get a bunch of rest so you can swim very fast again. This then becomes 20 x 150, as 100 hard, 50 easy, as swimming a hard 100 is much different than a hard 50.
WJ, how do swimmers train these days?
On the balance between threshold swimming and very fast swimming, I can only answer for what I observe locally.
That said, I think there is a pretty big parallel between what you have us do in general terms for an IM cycle and what the swimming kids are doing (over a shorter season). Both are "get generally faster through threshold work" early and then switch to more race-specific work.
In early-to-middle season, the dreaded set for the whole team is something like "6 x 200 for fastest possible average time, leaving on the 2:20" (For kids whose tapered times are around 2:00, and this is maybe 10 seconds rest in a workout). Sets like this are sort of like 100% FTP bike intervals. This is the threshold stuff.
As the season advances, the squad as a whole does less threshold work...though the distance swimmers keep up more. In the heart of the season (i.e., middle of regular competition through beginning of early taper), the distance freestylers will do something like "broken 1000", meaning 10 x 100 with an intention that they hit a goal 1000 race pace and get several (5-10) seconds rest before taking off for the next 100. But in principle, that's not very different than the 6 x 200 threshold set I mentioned before.
By the time championship season is in sight, there's a lot more short, very fast intervals with more rest...but again, there is some variation depending on whether they are sprinters or distance kids.
This last year, the coaching staff went to more, shorter sessions per week (for the teenagers) rather than fewer longer sessions. This was a change to get in more really fast swimming...but of course, most of the team is doing very few races longer than 200 y/m. As a parent, it was a little inconvenient because it was more 2-a-days. But the first season they did this, our club won the state championship for the first time. Causal? Who knows. Could just be the right group of kids that would have won anyway...but it worked.
I could comment on HS vs club, but that's getting pretty deep in the weeds. The above is club.
Absolutely love Coach Rich's fast/slow swim wko's that I had some confirmation for when I read an article or comments from a guy who said most people don't rest enough between sets... His go to wko was 100yd all out, hang on the wall 1 min, 100yd easy , hang on wall 1 min , repeat! I usually hack this to go 100 fast , 10 sec rest , 100 slow, 20 sec rest, repeat.... between the slow 100 and that 20 sec rest you are ready to swim another hard 100.... As soon as the fast ones start to fade you are done!
Addressing Rich's point, I swam the mega-yardage little rest approach through high school, but changed to a quality-based approach in college. Both worked for me, although I saw greater relative improvement in college using the quality swims method. I wonder whether having the huge aerobic base I built up in high school allowed my college gains to happen. And I strongly prefer the 150's set Rich describes than then 100's set because I don't personally get much out of 50's fast just like I don't feel I get much out of doing lots of 200 meter reps at 5K pace. Maybe a few at the beginning of the VO2 bock, but not as a mainstay. I just need roughly a minute of all-out work before I feel like I am doing something.
Addressing the original question, I think that you can estimate within 5-7 minutes what your time will be and that a long course race rehearsal is a pretty good estimate, as long as you don't succumb to the temptation to go all-out -- if you are winded and sucking air at the finish, you went too hard. But swim times are subject to a lot of variables that you can't anticipate or control, like current, waves, whether you catch a good draft or someone who blows up, and whether the course is accurate or not, as well as variables you can only control to a limited extent like how crowded the swim is and whether you swim a straight line. So, I don't worry about the absolute time so long as I execute the swim as I planned.
WJ, yeah, I forgot about the realities of 5-6 kids in a lane leaving 5" apart
. I guess my example would be like that 1:05 repeat guy doing 300's on ~4-4:30, trying to go sub 3:10 on all, probably with an easy 50 between each because you just can't sit on a wall for longer than 10-15" 
Whatever, I just want Rich to rewrite 2000 swim workouts in November (again).
From a practical standpoint, changing a send off interval system requires a whole 'nother level of explanation. Not to mention if you think the swim stuff is jacked up with me saying every swim in ENville is 60', just wait until I start having to ballpark what send off a Beg, Int, Adv swimmers should be doing for a set, then extrapolating that pace out to 200, 300's, 400's, etc. So I would have be doing time-math AND distance-math.
For example, 4 x 400 on a 1:50/100 send off =...thinking...a 7:20 per 400 send-off.
Trust me...you don't want me doing any more math than what is absolutely necessary.
High school after school workouts are apparently shorter, more like 5000-6000 but they have 4 2-a-days (and a 6th single workout day.
This is just a broad average...not taper time or the monster build early in season.
Just doing math here...
I did doubles on MWF for about 12k on those days. Tu THu call it 7k each. Saturday would be 8-9k = ~50k/wk. My right shoulder was shot by the time I was 15yo, chronic pain until about 2yrs ago when I had my shoulder surgery.