Home Racing Forum 🏎

IM TX Temperature Impact on Run Pace

24

Comments

  • Posted By Tom Glynn on 28 May 2011 10:18 AM

    Matt, is this application available to tinker with? I'd love to do a bunch of "what-if" scenarios, but not quite sure you want my couple hundred emails asking until I have the perfect race plan



    Tom, the app got its final blessing a few days ago. It needs a few final tweaks (like adding in 3 minutes for the first six miles.) The plan is to have EN Tech Guy put it up for access by all members. I suspect this will happen within a couple of weeks. So far, Matt and the sounding board of members he used while developing it have copies of the Excel spreadsheet in its beta form. As a member of that group, I would very much like to see it available for those racing in 4 weeks @ IM CDA.

    I've played with it a bit, using my times from specific races with known temps, and it is highly accurate across all temp ranges. It seems to work best for those with higher VDOTs (say, the top 40% of the field), so in its current version, it should function very well for your scenarios. Since Matt is leaving for India in a few days, and I'm here at my training camp in CO with little to do except "Swim, Eat, Bike, Run, Sleep" I'll volunteer to run your VDOT and a few Kona scenarios for you - Kona temps really don't vary that much, from 82 to 90 F is the range. Do you want me to use 53 for your VDOT, or are you going to get faster?!

    PM me if you like.

  • Al, thanks for taking the front position or the next few days!

    Tom, you are in more than capable hands!!!
  • Al/Matt,
    Is there a similar analysis for bike in hot/humid conditions ? I know it "shows" on the run, but there has to be some effect, even with evaporative cooling...
    Bill

  • Bill you are an excellent straight man!!

    We  have all the data  and the protocol for a look at the bike and temp impact. The  concern is the wind speed and relative direction can have a significant impact. I have those numbers,  the huge challenge will be how to incorporate wind into the mix. Ok then you have the second order impact of  the amount of hills on a course. I can’t find a standard way  to model the impact of hills. The use or average feet /mile gain per mile has been used by sites I have reviewed. – MORE WORK TO BE DONE!!!   I expect some edge to be found for the EN Team !!!! This is on the list of what to do with spare time!!!

     

     

  • Matt, does BMI have any role in these calculations? I was wondering whether a smaller athlete with the same VDOT would generate the same numbers since body cooling is harder for bigger athletes.
  • @ WJ - To expand on Matt's points, and to use a bit of research language (I am not a scientist, but I have been taught by a number of real scientists) - The dependant variable we are modeling for is either pace for the run, or power for the bike. There's no question that heat (an independant variable) requires one's pace to be modified for a successful long run. What we don't really know is if the same rule applies for power on the bike. Certainly hills and wind affect one's speed, but by holding one's power steady, those independent variable vanish from the equation. Personally, I think the effects of wind chill at 20 mph +/- mitigates to a much greater extent the need to alter power on the bike, compared to altering pace on the run for the same conditions. What one MUST do, of course, is up the hydration and use other cooling measures on the bike at 90F compared to 65F. But I'm not convinced that, once cooling measures and holding power steady for the nature of the course and wind, there's a further need for commpensation on the bike large enough to require a spreadsheet like we've got from Matt for the run.

    @JB - I'm sure there is a difference for someone like me (BMI 21.5, weight 143 #) compared to someone who is, say 6'1" and 180# - it's easier for me to dissipate excess heat than the person withthe larger surface area. The question is, is it necessary for that larger person to lower his speed (pace) by a greater %-age than I do, assuming one uses sufficient cooling measures? That might be a factor for the second generation of this app. For now, it is hard enough to get people at a race like TX or LOU to believe they must slow their pace by as much as 80-90 seconds a mile to have a successful run. One step at a time, I guess. If we get a season's worth of data from the > 100 ENers who will be using this app and then recording their race data on a companion spreadsheet Matt has generated, and find that there is a correlation between BMI and % reduciton in speed required, that might be factored in on the next go aroound with things like gender, age, and hilliness of the course, all of which werfe also suggested as potentialo factors to be considered, but felt to be much less signficant that heat/humidity. Also, there was little easily translatable data available to analyze to modify the equations used.

  • Al – I’m good at spreadsheets and numbers, you are great at communicating! I would have use 3X the words and still would be less effective in getting the message communicated.



    On the heat and BMI view the larger / heavier individuals are at a distinct disadvantage to a smaller athlete. If I remember correctly, the volume (weight) goes up as the 3rd power and the surface area goes up by the 2nd power. So a 140 lb person has a major advantage over a 180 lb person in hot temperatures. The 180 lb person can be just as fast as the140 lb person but they have to do more work to move their mass along the course at the same pace. The 180 lb person has less relative surface area to dissipate the heat generated by the greater work. They will overheat first and have to slow down in hot conditions.



    I think I found an paper on this as we were doing our heat research, will have to look again.



    PS –The EN Nation race Results Database sheet that  Al referred to will go live when I get back from India in 2 weeks. I expect it will need some hand holding in the first few weeks.

  • Thanks for the info guys, this is great stuff. I unfortunately am the 6'2" 185 lb guy any help I ca n get will be great!!
  • Jeff, You are in good company , Torbjorn Sindballe is also 6'2" and 178lb 3rd place at the Ironman world championships in Kona, Hawaii in 2007 together with two world long distance championships in 2004 and 2006. He worked all edges to stay cool in Kona. This includes all white cooling fabric outfits to ice in a plastic glove on his left hand. He was a rocket on the bike but the run in the heat was a problem.



     

  • Least you're not 6'0" 208# like me! (down from 241)
  • Jonathan Great progress!!!
  • Hey thanks Matt! Today I learned a lot about cooling. Am going to try and drop about 15-18 lbs of fat between now and Kona, bout a pound of week. Need to eliminate the refined carb crap I routinely eat. And I bought a wok and am going to teach myself to cook and eat healthily! image
  • This is really interesting.   Does the tool have application for HIMs as well?  I've been training in Seattle at and avg temp of 50, and am doing Honu is a few days.  The temp on race day is expected to be 83. 

    Thanks

    Dana

     

  • Matt - are you going to post this in a wiki with instructions (and maybe an excel spreadseet) so it's easy to find and use?
  • @ Bob, The EN Web guru is working on getting the application up in to the site in some form. It will have instructions and a FAQ section explaining key items. I’m not totally sure on the timing – next few weeks.

    @Dana Good luck the half!!! The data that build the curves is from Full IMs. I would expect the impact of heat a half to sill be a major factor just not as bad as a full. If you have not been able to do any significant heat acclimatization then a humid 83 degrees is going to be HOT. Start slower on the run than you think you should. My best guess is 10-15% slower than you target So for example a 9 min pace add 54 - 80 sec.
  • @ Dana: having played with the spreadsheet, and having run in that heat (as has Matt), I'd concur with the estimated pace reduction to aim for: 10-15%. The actual number would be 12-13% from the app, but I bet that the faster pace requires you to be on the high end of the reduction - 15%. And don't forget to add 30 seconds to that for the first three miles! Good luck, and stay hydrated.

  • Posted By Matt Samojeden on 27 May 2011 08:04 PM

    Victor, Thank you for posting. You bring forward a new challenge for the application. I used the EM IM pacing table to pull “Best day race times” based on a Vdot. The trouble is the table stopped at a Vdot of 30. Please don’t take any non positive implications from this!! You are a part of the EN team and will get faster via Work Works!!!

    Ok so what can the app say given the data we have. Based on your TX bike finish time, you would have started the run course at ~ 5:00. With A Vdot of 30 the EN best Possible Race day time is 5:32. The impact of the temp was a significant 30% resulting in a projected run time of 7:13 or a 16:25 pace. Can you say a long HOT day!!!

    Thanks Matt.  Certainly no non-positive implications taken on my part.  I have some work to do, I know.  I'm glad this thread split off into discussion on BMI and body weight and the effects of temp.  I know that my being 6'1" and 240 presents some serious challenges for me, especially in a race like IMTX.  My high water mark was 375 back when I was a rotting couch potato and I've come a long way.   I know I was right there with being able to finish this race. 

    Reading Michael Simpson's story and others' about how they overcame the pain of blisters and other painful situations, I have some work to do on handling painful things that come up during the race.  I think I could have been tougher when my back started really slowing me down.  But running this race 40-50 pounds lighter next year is going to go a loooooong way towards finishing this thing.

  • Thanks Matt and Al.

    I'll try that on race day and let you know how it turns out!!

    Dana
  • I will be able to add another HIM data point after this weekend's race.  Other than the cold front we had a couple of weeks ago, it has been pretty HOT and HUMID and will be so on Saturday (Oh Joy!).

    My VDOT 5k was about a month ago, but it was at 67deg versus the 85-90 that is forecast for when I will be getting off the bike.  My Race Rehearsal #2 a week and a half ago was just about 85deg when I started running.  My plan was to add 15" on top of the 30" for the 1st three miles.  That meant a goal pace of 8:01 for miles 1, 2, and 3.  Like I am wont to do, I over-did it and ran 7:54, 7:50, and 7:55.   I was unable to significantly step it up for miles 4, 5, and 6 (7:51, 8:03, and 7:43 -- last one mostly downhill).  Which tells me that a 7:16 MP is not in my future for Saturday.

    Based on the discussion above, I am going to add 10% to my MP (+30" for 1st 3 miles) and see how that feels.  MP+10% for me will be 8:00 (rounding).  Sitting here right now, and thinking about how my long runs have felt these past four weeks where I was having trouble hitting the goal paces, 8-minute miles sounds reasonable and do-able.

    I will be sure and let you all know how it goes.

  • Matt and Al I have a HIM this weekend High temps projected to be 92 with humidity of 65-70%. I'm a big guy at 260# with a low vDot 32. . I do train in a hot and humid area (South Fl) but usually in the AM except for weekends so I am relatively acclimated. Should I drop my pace 10-15% as recommended for Dana or would you y'all suggest a greater reduction. Though much slow and I will be walking. LOL Thanks for the hard work and input.
  • Yes Dewey, drop it at the outset and if you feel too good by 1/2way you can pick it back up again!
  • Dewey, those are SCARY HOT temps if the forecast conditions come to pass. They will be hotter that the hottest conditions for any IM race we have in the data base. Be safe is your first priority!!!



    Up at those temperatures and humidity you will get no cooling from sweat. Use ice sponges and ice in the hat and down the jersey at every aid station. The bad news is the app says for your vdot at those temperatures in a full IM,  most people slow down ~ 35% as compared to there best race day target. The Half IM should be less severe.



    Note that Dana’s race temp was forecast to be 83 not 93. You should expect to slow down more the 10-15% recommended for her. I would go with a 20-25 % and and see how you feel. If those temps are real, many people will not be able to walk a marathon without diligent use of extra cooling measures.



    Best of luck – again be safe!!



     

  • I have a question regarding how this all fits into the EN definition of work and the whole pace + gps method of run training.

    It says in The Book that pace is a better gauge of intensity (vs. HR) because it directly relates to muscle loading or motor recruitment (muscle work).  Pace is the objective measure of intensity, not HR which can change with temperature, humidity, hydration, etc. But, this new tool suggests that intensity, at least on race day, is more related to temperature and humidity than to pace and that intensity goes up and down and is dependent on temperature. (btw, this may very well be where I am making a wrong assumption).  So, what I'm saying is that race day intensity more closely tracks with HR (and the things that affect HR) than it does pace.

    This begs a couple questions in my (small) mind.

    1) Doesn't this fly in the face of the EN philosophy of pace-emphasis?

    2) If what I'm implying about intensity on race day is true (again, I may be totally wrong), then wouldn't it also hold true for training.  So, wouldn't my training intensities more closely track my HR, depending on temperature, humidity, hydration, time of day, etc. than trying to hit a particular pace defined by VDOT?

    So, I guess what I'm really asking is if we're suggesting that we slow down and do less work (as EN defines work) on race day if the temps are X to maintain z1 intensity, then wouldn't the same hold true for any given training session at any given intensity?

    I'm ceratainly not trying to start a fight here.  Besides, that's what this place is all about, right?  Not only understanding the what but also the why?  Thanks ahead of time for the responses.

  • Coach P and Matt thanks for the input. I will drop back a little more if the forecast holds and see how it goes. I'll let y'all know. Also Matt if you would like the data for the HIM stuff let me know be glad to provide. Though an n of 1 at these temps may not add much.
  • I'd love to use a derivative of this for Eagleman over the weekend... is this spreadsheet available for download so I can tinker with it for Eman?
  • Posted By George Schlossnagle on 09 Jun 2011 12:43 PM

    I'd love to use a derivative of this for Eagleman over the weekend... is this spreadsheet available for download so I can tinker with it for Eman?
    George, The spreadsheet is being worked into the EN web site. If you wish In the interim I can run some scenarios for you. Send me your Vdot and some temps and I will post the resulting paces.





     

  • May I chime in for Eagleman too? 210 lbs vdot 44, expected temps by the run = 78-85 degrees maybe. Thanks in advance for your time and advice!
  • For you Eagleman Racers this weekend.  Below is my best guess on temperature impact on run pacing.  The temps are forecast to be warm ++++  see the Wunderground.com forecast data below.

     

    I dropped this data into the IM pace app and obtained results for a range of VDOTS.  To make a quick best quest adjustment to a 70.3 race pace I used the ratio of best race day pace from the EN IM and 70.3 pace sheets.  

     

    This used the same % pace impact as the IM against the 70.3 best race day paces.  I think this will be conservative.

     

    The results are in the table below.

     

    Best of luck to all the EN team!!

    Matt

     

  • Posted By Victor Kaiser on 06 Jun 2011 05:41 PM

    I have a question regarding how this all fits into the EN definition of work and the whole pace + gps method of run training.

    Victor -  let me get the let me get the cobwebs out of my head from a 36 hr commute from India today and I will respond to your questions this week end.

     Matt

  • Thanks Matt.  Appreciate it a bunch.

Sign In or Register to comment.