Part 2-Temperature Effects on Half-Marathon Times

I received some good comments in my previous post. One suggested that I include the 2000 results which was a particularly warm day. So I did some more work and added in not only 2000 results, but also 1999 and 1998.

The temperature in 2000 was indeed warm. About 1hr into the race (9:55am), the temperature was about 76°F. This provides the much needed 70°+ race data. Unfortunately, 1999 and 1998 were both in the 60's (similar to 05, 04, and 01).

The 2000 race results definitely show the effects of heat. As can be seen by the bold plus signs in the 2000 column in the table below, most all of the categories' finish times were way above average (move your mouse over the cells to see exact times). The only exceptions are the female median times for the forties to fifties age groups. As I mentioned in the previous post, other variables must be having more influence here.

This 2000 race data changed most all the slowdown rates considerably. For example, the rate of slowdown for 500th place male twenties age group was 9 before the 2000-to-1998 data was added. This represents 9 seconds longer finish time for each degree Fahrenheit. With the 2000-to-1998 data, this rate changes to 38. This was over a 4X change. The average change seems to be around 3X.

It seems these results indicate that the linearity breaks down somewhere between 67°F and 76°F. For example, for every degree rise in temperature around 60°F, the finish times may rise 9 seconds. For every degree rise in temperature around 70°F, the finish times may rise 38 seconds.

Well, I'll keep collecting data which will hopefully include more 70+ degree temperatures and see how the plots look. As was mentioned in the comments from the last post, there are many complications. For example, shade will have an impact. The temperatures that I've used are official temperatures which are measured in the shade. Most of the race is in the sun. So the actual race temperatures will likely be higher on sunny days.

Half-Marathon Finish Times vs Temperature (Move mouse over plus/minus cells to see exact finish times for the specific year)

Age Category	Average Times Across All Races	Compared to Average								Avg Slow Down Sec/°F
		2 0 0 3 53°	2 0 0 2 54°	1 9 9 8 61°	2 0 0 5 63°	1 9 9 9 64°	2 0 0 4 64°	2 0 0 1 67°	2 0 0 0 76°
Ideal runner (as an example)
agegroup	1:32:44	-	-	-	+	+	+	+	+	9
Male 10th place runner
twenties	1:10:18	+	-	-	+	+	+	-	+	9
thirties	1:15:44	-	-	-	-	-	-	+	+	7
forties	1:18:08	+	+	-	-	-	+	+	+	7
fifties	1:27:16	-	-	-	-	-	-	-	+	20
Male 100th place runner
twenties	1:29:23	-	-	-	-	-	+	-	+	15
thirties	1:27:37	-	-	-	+	-	+	-	+	13
forties	1:30:04	-	-	-	-	-	+	-	+	13
fifties	1:42:39	-	-	-	-	+	-	-	+	35
Male 500th place runner
twenties	1:49:48	-	-	-	-	-	-	-	+	38
thirties	1:42:19	-	-	-	-	+	+	-	+	32
forties	1:45:27	-	-	-	-	+	-	-	+	31
fifties	2:06:51	-	-	+	-	+	-	-	+	69
Male median runner
twenties	2:01:52	-	-	-	+	-	+	-	+	44
thirties	2:02:25	-	-	-	+	-	+	-	+	41
forties	2:05:53	-	-	-	+	-	-	-	+	43
fifties	2:17:55	-	-	-	+	-	-	-	+	39
Female 10th place runner
twenties	1:29:04	-	+	+	-	+	-	+	+	21
thirties	1:28:46	-	+	-	-	+	-	+	+	13
forties	1:33:36	-	-	-	+	-	+	+	+	21
fifties	1:50:36	-	-	-	-	-	+	+	+	23
Female 100th place runner
twenties	1:44:39	-	-	-	-	+	-	-	+	30
thirties	1:45:03	-	-	-	-	+	-	+	+	28
forties	1:53:26	-	-	+	-	+	-	-	+	31
fifties	2:18:17	-	-	+	-	+	-	+	+	43
Female 500th place runner
twenties	2:01:14	-	-	-	-	+	-	-	+	44
thirties	2:03:18	-	-	-	-	+	-	+	+	47
forties	2:17:00	-	-	+	-	+	-	+	+	52
fifties	3:08:42	-	-	+	-	+	-	+	+	51
Female median runner
twenties	2:24:14	-	-	-	-	+	-	+	+	30
thirties	2:35:26	-	+	+	-	+	-	+	+	16
forties	2:51:49	+	+	+	-	+	-	+	-	-19
fifties	3:05:50	+	+	-	+	+	-	+	-	-35

For information about how to use this table and for more background, refer to my previous post.

The above stats are based on results from the Indianapolis 500 Festival Mini-Marathons for 2005, 2004, 2003, 2002, 2001, 2000, 1999, and 1998.

The temperatures are based on data from weatherunderground.com history for Indianapolis, Indiana for 05/07/2005, 05/08/2004, 05/03/2003, 05/04/2002, 05/05/2001, 05/06/2000, 05/01/1999, and 05/02/1998.

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