RunningAHEAD - Topic: The effects of heat and race times.

Eustace Tierney

YoYo

posted: 6/2/2008 at 9:36 AM
modified: 6/2/2008 at 9:37 AM

The weather is getting warmer over here in Ireland. Hey we might even reach the 80's in the next few weeks. Does the heat really affect race times presuming you are already well hydrated and take on fluids during the race. I have a race in 3 weeks and presuming I am injury free am hoping for a PB. Are temps between 80 & 90 likely to afect my time. Are there any stats compiled for this.

"The will to win means nothing without the will to prepare." Goals: Keep on running!

mikeymike

posted: 6/2/2008 at 9:48 AM

There are stats out there and I'm sure you can find them if you look hard enough. I remember seeing a chart from (I think) Jack Daniels that broke it down by temperature and by distance. The thing is though there is a lot of individual difference from person to person so you may be much more or less affected by the heat than the averager person in the chart. The bottom line is yes, heat affects race times. The longer the race the more heat is a factor. I've found I can race well at 5k to 5 miles in hot weather (up to 90 degrees) but performance drops off quickly after that. And 80 to 90 is really a huge range. You might be able to race really well at 10k in 80 degree weather but completely fall apart in 90 degree weather.

Runners run

Ennay

A Saucy Wench

posted: 6/2/2008 at 10:08 AM

A lot of it has to do with how acclimated you are. I run primarily in cold and cool weather year round, so I am greatly affected by heat. This is what Galloway says:

Adjusting Race Pace for Heat: Estimated temperature at finish - Slower than goal pace - 8 min mile becomes... 55-60 degrees - 1% - 8:05 60-65 degrees - 3% - 8:15 65-70 degrees - 5% - 8:25 70-75 degrees - 7% - 8:35 75-80 degrees - 12% - 8:58 80-85 degrees - 20% - 9:35 Above 85 degrees - Forget it... run for fun * Note: This chart is based upon my own experience in the heat and talking to other runners. It has no scientific verification.

This seems extreme to me...last year I ran a HM at ~52 degrees at an 8:56 pace and a month later a HM at 70 at a 9:00 pace. - now I had trained in between well, so I was thinking I could do closer to an 8:50 - but even with that its a much smaller drop off than galloway suggests. And I have as little heat acclimation as anyone could possibly have.

I have become Death, the destroyer of electronic gadgets

"When I got too tired to run anymore I just pretended I wasnt tired and kept running anyway" - dd, age 7

Trent

Good Bad & The Monkey

posted: 6/2/2008 at 10:13 AM
modified: 6/2/2008 at 12:11 PM

Jhorner recently posted this, elsewhere:

http://scienceofsport.blogspot.com/2008/05/fatigue-series-part-5-exercise-in-heat.html Essentially, they claim that there's something in our makeup as humans that forces the body to recruit less muscle when exercising in the heat so as not to increase our core temperature to an extreme point, and they've got some science to back this up.

Tinman:

Heat Index	Total Performance Change	Sample Adjustments to Pace
		Per Mile	Per K
120F	+16.33%	5:49	3:36.9
110 F	+12.00%	5:36	3:28.8
100 F	+8.33%	5:25	3:22.0
90 F	+5.33%	5:16	3:16.4
80 F	+3.00%	5:09	3:12.0
70 F	+1.66%	5:05	3:09.5
60 F	+.33%	5:01	3:07.0
50 F	0%	5:00	3:06.4
40 F	+.33%	5:01	3:07.0
30 F	+1.66%	5:05	3:09.5
20F	+3.00%	5:09	3:12:0
10F	+5.33%	5:16	3:16.4
0F	+8.33%	5:25	3:22.0

I'm running somewhere tomorrow. It's going to be beautiful. I can't wait.

Poor baby

brerfootbill

Half Fanatic #846

posted: 6/2/2008 at 10:15 AM

Pay just as much attention to high humidity as you do to high temps and hydrate properly. I seem to race a little better at a higher temp. with lower humidity than vice versa. But together they can be really bad! Tongue

I don't know how it is in Ireland, but here in north Florida we've already had 95 F with 85% humidity recently ... I was mowing the yard this morning at 8:30 and dripping with sweat! Bill

"I don't always roll a joint, but when I do, it's usually my ankle" - unk. "Frankly autocorrect, I'm getting a bit tired of your shirt". I ran half my last race on my left foot!

mikeymike

posted: 6/2/2008 at 10:30 AM

Ennay, I agree acclimatization makes a big difference. And that Galloway chart is complete nonsense.

Runners run

jEfFgObLuE

I've got a fever...

posted: 6/2/2008 at 10:38 AM

This calculator does a zillion things, include temperature (from Daniels).

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.

Eustace Tierney

YoYo

posted: 6/2/2008 at 11:49 AM

Thanks folks. Had just found the Daniels calculator. Seems I can expect a 1 and a half minute increase over 10k if the temperature hits 85. This will be dissappointing as i'll never break 40. Lets hope for cooler weather. Who knows, this is Ireland, it might even snow.

"The will to win means nothing without the will to prepare." Goals: Keep on running!

Save Cheevers

posted: 6/2/2008 at 1:14 PM

Quote from Trent on 6/2/2008 at 10:13 AM:

Jhorner recently posted this, elsewhere: Tinman:

Heat Index Total Performance Change Sample Adjustments to Pace

Per Mile

120F +16.33% 5:49 3:36.9

110 F +12.00% 5:36 3:28.8

100 F +8.33% 5:25 3:22.0

90 F +5.33% 5:16 3:16.4

80 F +3.00% 5:09 3:12.0

70 F +1.66% 5:05 3:09.5

60 F +.33% 5:01 3:07.0

50 F 0% 5:00 3:06.4

40 F +.33% 5:01 3:07.0

30 F +1.66% 5:05 3:09.5

20F +3.00% 5:09 3:12:0

10F +5.33% 5:16 3:16.4

0F +8.33% 5:25 3:22.0

I've found this to be pretty accurate.

Viich

posted: 6/2/2008 at 1:25 PM

It's very individual, I think. For me, anything 25C or above is pretty much a write-off as far as a decent time is concerned, and 30C is an extra minute or more on a 10K.

meggie

posted: 6/2/2008 at 1:49 PM

If you're not used to running in the heat, then it most likely will affect you. It also depends on the length of the race and how fast you are as a general rule because those factors determine how long you're going to be running. The longer you spend in the heat, the more it's going to impact your time. Personally, I prefer very hot weather over very cold weather for running, but I think I might be in a minority there.

Ennay

A Saucy Wench

posted: 6/2/2008 at 1:54 PM

Quote from meggie on 6/2/2008 at 1:49 PM:

Personally, I prefer very hot weather over very cold weather for running, but I think I might be in a minority there.

You and my dh...he thinks 85 is cold

I have become Death, the destroyer of electronic gadgets

"When I got too tired to run anymore I just pretended I wasnt tired and kept running anyway" - dd, age 7

BenBuck6

posted: 6/2/2008 at 2:18 PM

Currently At 1:15PM[ More ] 90°F RealFeel® 101°F Winds: WSW at 9mph Sunny The current forecast here ... The heat index and humidity here is what pushes things to unbearable points. RealFeel (Heat Index) - 101 degrees Shocked

It's only June2

2008 GOALS GET BELOW 175 (at 175 now) RUN 6:00 MILE (at 6:29) RUN BELOW 25:30 5K RUN BELOW 55:00 10K RUN A MARATHON (DEC. 6TH - MEMPHIS - ST JUDE)

Teresadfp

One day at a time

posted: 6/2/2008 at 2:29 PM

My condolences, Ben.

Pron8r

posted: 6/2/2008 at 3:21 PM

Quote from meggie on 6/2/2008 at 1:49 PM:

If you're not used to running in the heat, then it most likely will affect you. It also depends on the length of the race and how fast you are as a general rule because those factors determine how long you're going to be running. The longer you spend in the heat, the more it's going to impact your time. Personally, I prefer very hot weather over very cold weather for running, but I think I might be in a minority there.

I agree. I love running in the heat (which is a good thing, since I live in Las Vegas). Run right after work, when it's the warmest. In the summer months, it's usually high 90's to low 100's when I run. However--I have found over the years that, running every day at about the same time, you tend to acclimate to the temperature. No question I run faster at cooler temps, but I don't slow down that much at higher temps. The only concession I make over winter running is that I carry a water bottle with me from time to time. Yes, Las Vegas is a dry heat ('course, so's your oven, but you don't go sticking your head in it--it's still hot), so I can't comment on the effect high humidity in combo with the heat would have.

My Masters (>50) Race PR's: 5K - 20:17 10K - 42:36 HM - 1:31:22 Marathon - 3:20:48

The effects of heat and race times. (Read 840 times)