Interesting article on the (in)accuracy of race time predictors (Read 524 times)


I'm back!

    But the 25 minute 5kers include some folks jogging at their regular pace and others going all-out. 

     

    I think the point is, going all out for 15 minutes is not the same as going all out for 25 minutes. You can only run at VO2Max effort for so long before lactate begins to build up and you have to back off.

     

    Likewise, a world-class marathoner has a very different kind of race at 2+ hours than I do at 3 hours. They can run closer to their lactate threshold, because they don't have to do it as long.

    JimR


      The question around energy systems should be related to the time involved, not the distance.  i.e. running 25 minutes at the effort levels you need for 25 minutes as opposed to running 15 minutes and the effort levels required for that.

       

      eta: bhearn beat me to it

         

         

        Likewise, a world-class marathoner has a very different kind of race at 2+ hours than I do at 3 hours. They can run closer to their lactate threshold, because they don't have to do it as long.

         

        Oh, so for me to run to run a faster marathon and not bonk, I just need to run faster?

        it sounds so simple! Why didn't I think of that :-)


        I'm back!

          Exactly!

             

            The world records from 1500m to marathon fit remarkably close to the 1.07 exponent.  

             

            Interestingly, the world records from 1500m to marathon do not all belong to the same guy.   So, apparently some people are really better at some distances than others, even though apparently as an ensemble they fit the model pretty well.  (that's at you, Bob.  Joking Wink

            - Joe

            We are fragile creatures on collision with our judgment day.

              I find the prediction calculators to be pretty accurate.  When my training is at it's best, I am pretty much equal to most those calculators from  5K to marathon given conditions etc..   A bit slower than predicted in the shorter distances if you go shorter than that... I think. I never did it in a race setting. Nor wanted to.

              In the lack of speed slogging away training that is the last couple years, I do better at ultra or marathon than would be predicted by 5K or 10K.

               

              Most the people I know who far underperform in the half and marathon verse 5K are not trained very well for the longer distances. (Though I know at least one guy who is naturally speedy and can't touch what his 5K says he should be able to do - not even close - with dedicated and careful training)  But that wouldn't be most.

              Current Weight: 160 lb

              Goal Weight: 130 lb

               

                (Though I know at least one guy who is naturally speedy and can't touch what his 5K says he should be able to do - not even close - with dedicated and careful training)  

                 

                That's what I'm talkin' 'bout!

                - Joe

                We are fragile creatures on collision with our judgment day.

                scappodaqui


                rather be sprinting

                  The question around energy systems should be related to the time involved, not the distance.  i.e. running 25 minutes at the effort levels you need for 25 minutes as opposed to running 15 minutes and the effort levels required for that.

                   

                  eta: bhearn beat me to it

                   

                   

                  That's all I meant. I wasn't making some deprecatory statement about 'slower' or 'faster' runners, just pointing out that the science of calculating paces accurately might depend a bit on energy systems, and thus, be more accurate for time instead of distance.

                  PRs: 5k 19:25, mile 5:38, HM 1:30:56

                  Lifting PRs: back squat 176 lb


                  No more marathons

                    Lots of variable that come into play.  I think one of the more significant is that your opportunities to run a "best" marathon are much more limited than for other distances.  It's really almost an all or nothing - so many things can happen on that one day that make or break the training.  And you arn't likley to run as many quality marathons in a given set of time comparable to the number of 5K, 10K that you could do.

                     

                    When I plug in my middle distance times (10K, 15K, HM) into McMilian I get reasonably consistent results.  And that was back when I wore a younger man's shoes, and now that I'm an old fart.  But I have NEVER been able to meet the projected marathon time.  Was I as well trained for those efforts?  Don't know.  I have six under my belt, and the two that I trained the most for were one's that I died miserably in while trying for that projected time.  Of course other factors (weather, diet, travel) came into play.

                     

                    So, for me, the 1.15 factor comes pretty close to my actual performance.  Is that simply a cop out to not training hard?  Maybe.  Or maybe my personal physicality says I can run the shorter distances well, but my endurance simply doesn't extend to the marathon.

                    zonykel


                      It may be that the formula is biased towards elite runners.

                       

                      if that is the case, there may be a divergence between the training an elite can absorb and a non-elite, and for whatever reason(s), those differences are accentuated in the marathon. And those elites at 5,000 and 10,000 meters may try the marathon, and if they feel they won't be competitive, they won't participate, thus continuing to leave the formula biased.

                       

                      I wonder if that divergence  is also true for ultras, where I presume there is less money than in the marathon.

                         

                        Interestingly, the world records from 1500m to marathon do not all belong to the same guy.   So, apparently some people are really better at some distances than others, even though apparently as an ensemble they fit the model pretty well.  (that's at you, Bob.  Joking Wink

                         

                        So maybe instead of race time predictors we should call them equivalent performance calculators.

                        Runners run.


                        Muddling through

                          Lots of variable that come into play.  I think one of the more significant is that your opportunities to run a "best" marathon are much more limited than for other distances.  It's really almost an all or nothing - so many things can happen on that one day that make or break the training.  And you arn't likley to run as many quality marathons in a given set of time comparable to the number of 5K, 10K that you could do.

                           

                          When I plug in my middle distance times (10K, 15K, HM) into McMilian I get reasonably consistent results.  And that was back when I wore a younger man's shoes, and now that I'm an old fart.  But I have NEVER been able to meet the projected marathon time.  Was I as well trained for those efforts?  Don't know.  I have six under my belt, and the two that I trained the most for were one's that I died miserably in while trying for that projected time.  Of course other factors (weather, diet, travel) came into play.

                           

                          This is pretty much my experience too. I would also note that what I consider the best marathons I've run were run under adverse conditions so the final times don't reflect the quality of the race.

                          2014 Goals: Run first trail ultra, first 100K, and see what I can do in a 24-Hour race

                          GC100k


                             

                            So maybe instead of race time predictors we should call them equivalent performance calculators.

                             

                            In that old spreadsheet I have that has the calculations I'm posting, I have a column with a "performance factor", which tops out near 1000 for the distance races.  Apparently a way to compare performances across distances.  Don't know where I got it (could google it), but the formula is:

                             

                            3337/(C3/(A3/1600))*(A3/1000)^0.0689

                             

                            C is the time in minutes and A is the distance in meters.


                            I've got a fever...

                              First I'll stipulate that world-class 5k runners (and milers for that matter) run a lot more miles than nearly all hobby-jogger marathoners and put in a lot more work.

                               

                              That being said, it is possible for most people to come fairly close to their "best possible" 5k with far less work than it would take to run their best possible marathon.    So most amateurs run far better 5k's than they do marathons, from an equivalency standpoint, because it's easier to get there.

                               

                              Someone made a really good point that the 1.07 for world records is not for one person.  It would be interesting to see what kind of factor world class athletes have over their own PR ranges.  I imagine since they're well-trained, there wouldn't be a huge deviation from the "ideal".

                               

                              FWIW, I'm 1.1012

                              On your deathbed, you won't wish that you'd spent more time at the office.  But you will wish that you'd spent more time running.  Because if you had, you wouldn't be on your deathbed.

                                Every runner has a sweet spot that is a combination of temperament and physiology.

                                 

                                My best distance at my physical peak in my early 20s was 1000-1500m. I was substantially worse from 800m down, then my performance equivalents gradually tapered off as I went up in distance.

                                 

                                I think that if I had kept training through my late 20s, my best distance would have been 5000m.

                                 

                                By the time I returned to training in my 30s, my best distance had become the half marathon.

                                 

                                I think these changes had more to do with my ability to concentrate and changes in my own personality and temperament than with physiological changes. I simply am not willing or able to go to the places I went as a young 1500m runner. But on the other hand, I am much more methodical and patient and tougher over the long haul than I was then.