SharonRunsDisney2023
Earning My Ears
- Joined
- Jul 20, 2022
- Messages
- 11
I did have to read it through a few times, but I found that very interesting. Thanks.It's an interesting twist on the conversation, because usually the question is why dew point instead of humidity. Humidity can be deceiving as a stand-alone value. Two runs can have 90% humidity levels but be vastly different conditions. A temp of 40F with 90% humidity feels way better than 80F with 90% humidity. Two runs that have a dew point of 70F or two runs with a dew point of 40F are going to be more distinguishable. The 40F dew point is going to be a good running day under most temp conditions. A 70F dew point is going to be bad running conditions under most conditions. The Temp in combination with the dew point helps define how bad a 70F dew point is or how ideal a 40F dew point is.
But what you're asking is why not combine Temp+humidity into a single value like we do for Temp+Dew. In theory it should also be possible. Whether a Temp+Dew of 150, whether it's 80F temp + 70F dew or 90F temp + 60F dew, are exactly equal is debatable, but they're close in how they effect your body (this is isolating these two values and ignoring solar radiation). I've seen this with my own personal data that more often than not, 150 is 150 and requires a 4.5% adjustment regardless of how it was composed. But more often the comparison that is best made is that 150 is way worse than 120, and 170 is way way worse than 150. Meaning the bodies response to the change in T+D is not linear, and a difference in these values creates a significantly different response.
What I don't have data on, is whether a 80F temp + 70% humidity (150 value when treating the % not as a %) and 90F temp + 60% humidity (150 value as well) are near equal. At 80F with 70% humidity, that's a T+D of 150 as well (70% humidity at 80F is 70 dew point) and 90F with 60% humidity, that's a T+D value of 165 (60% humidity at 90F is 75 dew point). So the T+H are equal at 150 each, but the T+D is 150 vs 165. My personal data would say that these T+H values, despite being equal, are going to produce vastly different body responses. That very well may be why T+D is a more preferred method over T+H. Because with T+D, a 150 is a comparable value despite how it's come to be, and a T+H value of 150 has a vastly different response depending on how it's come to be. Presumably a higher T+H value will yield less ideal conditions than a low T+H value, but if the values themselves are less comparable depending on how they came about, then it disrupts the ability to use it as a means to predict/change goal pacing.