How Heat Affects Performance

Affects of Heat on Performance

Temperature Affects upon Performance Chart
by Tinman
One challenge for runners is figuring how to adjust training and racing speeds relative to outdoor weather conditions. A common question arises: "How much time should I add or subtract from my normal pace as temperature changes?" 
In the chart below you will find performance changes for an example runner who normally covers 5:00 per mile when temperature is ideal.

* The formula I use below doesn't’t factor humidity or wind, so keep that in mind.
________________________________________
Heat Index Total 
Performance
Change Sample Adjustments to Pace Per Mile 

• 120F   +16.33%   5:49
• 110 F  +12.00%   5:36
• 100 F  +8.33%     5:25
• 90 F    +5.33%     5:16
• 80 F    +3.00%     5:09
• 70 F    +1.66%     5:05
• 60 F    +.33%       5:01
• 50 F       0%         5:00
• 40 F    +.33%       5:01
• 30 F    +1.66%     5:05
• 20F     +3.00%     5:09
• 10F     +5.33%     5:16
• 0F       +8.33%     5:25

* All rights reserved. December 20, 2005