Wednesday, July 25, 2012

racing, heat, humidity, sun energy

In preparation for the B2B next week, I've looked a little more into climate factors that affect pace. A very nice explanation of humidity and dew point is here. Dew point is the better guide to comfort level. Kristin Barry sums it up with this chart:

50–54Very comfortable PR conditions
55–59ComfortableHard efforts likely not affected
60–64Uncomfortable for some peopleExpect race times to be slower than in optimal conditions
65–69Uncomfortable for most peopleEasy training runs might feel OK but difficult to race well or do hard efforts
70–74Very humid and uncomfortableExpect pace to suffer greatly
75 or greaterExtremely oppressiveSkip it or dramatically alter goal
I've roughly estimated the mid-point T and dew point for my summer races for the past 3 years using the climate history data at weather underground.

Year Race                          T    Dew Point   Result
2012 Bridge of Lions (Florida)     78F     73F    18:32
2012 LL Bean 10K                   66      63     38:06
2012 Fathers Day 5K                61      48     18:12
2011 B2B 10K                       68      64     38:00
2011 LL Bean 10K                   65      65     38:30
2011 Mothers Day 5K                58      49     17:52 PR
2011 Clam Festival 5Mile           70      58     30:0x PR
2010 B2B 10K                       58      48     37:24 PR

I also think the directness of the sun matters (so the sun temp and not shade temp) since most of these races are run in direct sun and not shade but I don't have any historical record of sun temp.

What amazes me is the actual temperature of the maine races is generally very cool but comparing the dew temp with the chart shows that some of the races will suffer, such as both LL Bean's and the 2011 B2B. B2B 2010 was really perfect. And againmale runners over 35 y.o. and in top 400 who competed in 2010 and 2011 were, on average, exactly 1.0 minute slower in 2011 than 2010 (N=61).  In this light, I guess my Bridge of Lions 5K isn't too bad but it's really hard to compare since that is my only race in that kind of temp/dew point.


  1. I'm a big fan of statistical data and using it for predictions, but the beauty of it is that there are no absolutes and anything can happen, for better for for worse. You perhaps showed that when you roared at the Bridge of Lions. Perhaps the Beacon will guide you in to a new PR even if it is humid as a bastard. Carpe viam!

  2. I too spend a lot of time logging data that I think (but at least hope) will help me run better. I havn't however been able to tabulate any statistics that prove my statistics actually help my race times. I think for elite / consistant runners (like yourself), the statistics can be extremely helpful, for slightly behind midpack runners like myself, there are too many variables involved. That being said, I still find myself tabulating statistical imformation with the intent of helping me accomplish my goals.

  3. Unlike you three I don't usually pour over data. I see the benefits in it though and might start diving in to it more to fine tune. Ya know, get more 'efficient'. Thanks for the reminder, and interesting info.

  4. There are many variables Kevin but dew point is not something I've systematically looked at but for anyone trying to do summer workouts on the road or track, it should be considered. Workout (and race) paces can drop considerably and if this isn't accounted for, then it's hard to tell if a subpar performance is due to poor fitness, or the T/dew point, or over-training, or just a bad day. More importantly is to go into a workout with dew point in mind to adjust goal pacing. I've always done my summer workouts with the very optimistic goal of hitting my peak paces. Two summers ago that worked well. Last year not so well. I wonder if last summer was hotter and/or more humid.