Extrapolting short distance time to longer distances

This morning I had a 400m for time run and ran it in 1:40 or a 7:07 pace per my FR305. I looked on McMillan's Pace calculator and got all the different estimates. Now, I know a longer distance is a better measure of expected marathon finish time.

But my question is: At this point in time, could it be said my 400m time extrapolated to a longer distance is the best goal time I could do at my present level of fitness? Is there any merit in trying to put any credence in the estimated time at longer distances?

Because I was thinking, "Hmmm, I wonder if I really concentrated, could I get to that time?" And thanks for yours.

ounce wrote:This morning I had a 400m for time run and ran it in 1:40 or a 7:07 pace per my FR305. I looked on McMillan's Pace calculator and got all the different estimates. Now, I know a longer distance is a better measure of expected marathon finish time.

But my question is: At this point in time, could it be said my 400m time extrapolated to a longer distance is the best goal time I could do at my present level of fitness? Is there any merit in trying to put any credence in the estimated time at longer distances?

Because I was thinking, "Hmmm, I wonder if I really concentrated, could I get to that time?" And thanks for yours.

My short answer is no. The McMillan calculator is based on being adequately trained for the distance in question.

For example, if you input the current WR (Michael Johnson's 43.18) in to the calculator you get a 1:57 high marathon equivalent. Do you think Michael Johnson could run a 1:57 marathon. No chance.

So that's the bad news. The good news may be that you are starting to pinpoint where you need to focus your training. How do your 5k and 10k times compare to your goal marathon time in the calculator. The longer distances are better predictors because they are more aerobic in nature - much like the marathon. My guess is that, like most, you have the necessary speed to run your goal marathon time. Just not the aerobic endurance. That's unfortunately why we have to do LT and long runs. Argh.

Ben Z wrote: My guess is that, like most, you have the necessary speed to run your goal marathon time. Just not the aerobic endurance. That's unfortunately why we have to do LT and long runs. Argh.

And for distance events, average weekly mileage. In other words... RUN MORE!

I agree with Ben. McMillan is NOT a predictor. It is an 'equivalence calculator', meaning that a time of 'x' in the 400m is the equivalent of 'y' in the marathon, but it assumes proper training for the varying distances. Most agree that the marathon equivalence times are more accurate for those training at 70mpw or more.

Doug, I'll add that I think it is a relatively good indication that you could run close to the time that McMillan predicts. For me, I typically outperform the predicted marathon times. Historically I've had difficulty hitting the shorter race times that my marathon predicts. I've spent a couple cycles focusing on my speed and I've been able to bring my shorter races (5k) in line with my marathon. I just looked them up and they match perfectly. I don't typically run anything shorter than a 5k but the last time I ran a mile it was slower than predicted.

I'm with Tim here. My marathon times predict MUCH better 10k times than what I run. Why? Because I adequately train my aerobic engine and most of my LT work is Hal-style (I never do FCRs). If I started doing mile repeats, FCRs, and shorter intervals, I could probably bring down my 10k time to what is predicted. But then again, I think my marathon time would improve, too.

400m is probably a bit too short to extrapolate to marathons. A 10k time would likely be a much better indicator.

I'm kind of a strange case, probably because of where I've been in training and how I train. My 1 mile time correlates much better to my 10 mile to half marathon and marathon times than it does to my 5K or 10K times. My 5 mile PR is about as close to what my mile time predicts as my 10 mile and half are. Which tells me that I have natural speed and I've worked hard on my endurance, but haven't concentrated at all on the interval work necessary to run fast 5 and 10K times. And that makes sense based on the large amount of tempo work I've done getting ready for marathons.

Mike MacLellan wrote:400m is probably a bit too short to extrapolate to marathons. A 10k time would likely be a much better indicator.

...and a half marathon time would be a much better indicator than a 10K time.

Yeah the closer distance the event the better you'll be able to estimate finish time for the other event. My 10K time predicts a much faster marathon than I've ever been able to accomplish.

I'm exactly like Jim, and back in the day, I consistently ran 37-38 min 10Ks and sub 1:30 half marathons. However, I only was able to break 3 hrs in the marathon once as I just didn't/don't have the endurance mode to sustain the speed. Heck, my "raced" half marathon is not really a good predictor of my marathon times.

Michele "1L" Keane wrote:I'm exactly like Jim, and back in the day, I consistently ran 37-38 min 10Ks and sub 1:30 half marathons. However, I only was able to break 3 hrs in the marathon once as I just didn't/don't have the endurance mode to sustain the speed. Heck, my "raced" half marathon is not really a good predictor of my marathon times.

Exactly! The only reliable predictor is to actually get out there and race a marathon. Then use that info to plan your next training schedule. Trying to get a little faster each cycle/race.

The half is a lot different than the full too, I agree. There's a reason the current WR in the half, who routinely breaks 59 minutes, has only finished 1 marathon in 3 tries (I believe) running 2:12. With his half speed he should be 2:04.

The marathon is an event which is hard to predict.

Ben Z wrote:
Exactly! The only reliable predictor is to actually get out there and race a marathon.

Well no, because then its not a "prediction," it is a "result."

Dave-O wrote:

Ben Z wrote:
Exactly! The only reliable predictor is to actually get out there and race a marathon.

Well no, because then its not a "prediction," it is a "result."

Don't turn this in to a letsrun post Dave. I'm saying you would use the 'result' to 'predict' your next training/race. So yes, it is both a result and a predictor.

Ben - I'm curious, do you use the paces from your fastest actual race? Or your goal race? I always train at the paces that my goal time would warrant. Meaning if I want to run a sub-3, I'll type 2:57 into the calculator (I like a buffer, and 6:45/mi is such a nice round number) and run my training runs at those paces.

Ben Z wrote:

Dave-O wrote:

Ben Z wrote:
Exactly! The only reliable predictor is to actually get out there and race a marathon.

Well no, because then its not a "prediction," it is a "result."

Don't turn this in to a letsrun post Dave. I'm saying you would use the 'result' to 'predict' your next training/race. So yes, it is both a result and a predictor.

Not trying to, but its a pet peeve of mine when discussing the predictive value of McMillan, someone responds with "the best predictor is actually running the race." Because at the that point, it ceases to be a prediction. It just does.

And I disagree that a past marathon result is an accurate predictor of a future marathon. Frankly, plugging in a half-marathon result from 4 weeks before a marathon will have a higher predictive value than a marathon from months ago, in my opinion.

Dave-O wrote: Frankly, plugging in a half-marathon result from 4 weeks before a marathon will have a higher predictive value than a marathon from months ago, in my opinion.

+1

+2 Hence my desire to run a couple of "pace determining races" a month or so before a marathon. In the case this yr a 1/2 marathon and a 5 miler. Much more confident in those "predictors" than the marathon I ran last September.

Thanks for the comments, y'all. It does clear up the issue in my mind.

Dave-O wrote:

And I disagree that a past marathon result is an accurate predictor of a future marathon. Frankly, plugging in a half-marathon result from 4 weeks before a marathon will have a higher predictive value than a marathon from months ago, in my opinion.

I have to disagree with you. While I think there is value in racing a half 4-6 weeks before a marathon to see if your goal marathon time is crazy, I don't think it's super reliable, at least for me.

The reason being that most of us typically do not taper for a half marathon four weeks before a full. So while you can probably guess how you would have done in the half assuming you had tapered, you are only guessing. So adding more subjectivity in to the equation.

For example, in a half last year leading up to what was going to be a full marathon in the fall I ran just under 1:22:00. 1:21:58 I think. With a goal marathon time of 2:50:00 McMillan states I should be able to do a half in 1:20:36. Could I have run 1:22 faster if I tapered a bit more for the race? Maybe, but my marathon a few weeks later would have probably suffered.

I'd rather use my previous PR (2:55:XX) to plot out my training. Then, assuming I did all the training I felt was necessary, take a crack at 2:50:00. Running a less than ideal half in training is OK with me and I don't use it as a predictor because I know my full times outperform anything I can do at the shorter distances. It's just the way I am built.

Mike MacLellan wrote:Ben - I'm curious, do you use the paces from your fastest actual race? Or your goal race? I always train at the paces that my goal time would warrant. Meaning if I want to run a sub-3, I'll type 2:57 into the calculator (I like a buffer, and 6:45/mi is such a nice round number) and run my training runs at those paces.

I typically use paces that correspond to goal times. But it took me until this year to actually read the disclaimer on McMillan's website, it reads:

One note: The calculator is designed to prescribe training paces that advance your fitness above your current race times. Therefore, if you put in your goal time instead of your current time, then the suggested training paces will actually be faster than necessary for your goal time. For example, if your marathon goal is 3:30:00 and you input this into the calculator, it will provide training paces to run faster than 3:30:00, thus advancing your fitness from the 3:30:00 used in calculating your training paces. Many runners and coaches find it helpful to print out their training paces from their current race time and their goal race time. Over the training cycle, you should see your training paces advance from your current race time toward your goal race time training paces.

So I take advantage of the ranges McMillan provides. Often times I'm at the slower end of the goal time pace ranges in training due to, I hope, cumulative fatigue in my legs. That's why I can't wait for the taper to see if all the work has paid off!

Back to the original question about using 400m times to predict a marathon time, McMillan states:

Really for fun more than anything else, I've listed equivalent performance for distances you probably will never run, the 100m, 200m, 400m and 500m. While I've had a lot of success with equivalent performances at distances from 800m to the marathon, these shorter distances are just educated guesses. After all, it's likely that your genetic endowment of fast-twitch fibers plays a greater role in your pure sprinting ability than any training that you do. But hey, it's fun to think about your sprinting speed.

http://www.mcmillanrunning.com/index.php/site/calculator