Pace Changes - First vs. Second Half of Austin Freescale Marathon

Intro

Maintaining a constant pace through out a marathon is tough even in perfect conditions. Last Sunday's heat and humidity were anything but perfect for marathons. As would be expected, very few were able to keep a consistent pace.

I did these split stats a little differently than what I did for the 2004 marathon. The stats at doitsports for 2005 were in a little different format than previous marathons. The 2005 split times and paces were cumulative. So I haven't yet repeated the stats that I did for the 2004 marathon.

For now, I've coded up some new programs to look at the paces between the first and second half of the marathon. I partitioned the paces into speedup/slowdown minutes. For example, those who ran the second half 1 to 2 minutes faster than the first half were put into the "-2:00 to -1:00" category. For those who ran the second half 1 to 2 minutes slower than the first half were put into the "1:00 to 2:00" category.

Note, I had to exclude some runners who had fields with invalid data. So that's why my total is less than the 4958 total given at doitsports. Also note that I used the chip times. This created a little complication since the halfway pace provided in the stats was based on clock time. I had to do a little math to ensure both halves were based on chip times. This helps avoid having the stats skewed by runners who started far behind the starting lines.

Results

The first set of stats show the pace changes for all runners. Out of 4576 runners, I found only 147 (about 3%) who ran faster in the second half as compared to the first half. Out of these 147, only 9 ran 1 to 2 minutes/mile faster. The rest just ran up to 1 minute/mile faster.

About 97% of all runners ran the second half slower. 61% of the runners had second half paces up to 2 minutes/mile slower. 29% had paces between 2 and 4 minutes/mile slower, and 6% had paces over 4 minutes/mile slower. The missing 1% is due to roundoff errors.

I then wanted to know how this compared based on marathon finish times. I would expect the more experienced runners to have more consistent paces. So I looked at these pace for runners who ran the marathon under 3 hours, between 3 and 4 hours, between 4 and 5 hours, and over 5 hours.

As would be expected, the sub 3 runners were very consistent. 95% of them ran the second half within a minute/mile pace of the first. Only 5 out of 104 runners had slowdowns of over 1 minute/mile.

There were 1297 sub 4 runners. The consisteny starts to fall here. Only 59% maintained a second half pace within a minute/mile of the first. But most were able to keep a decent pace to finish sub 4.

Most of the runners fell into the sub 5 category (finishing between 4 and 5 hours). There were 1954 runners in this category. And you can see that the consistency again went down. 74% of these runners ran the second half over a minute/mile slower than the first.

Finally, the runners who ran the marathon in over 5 hours had even more second half slowdowns. About 87% of them ran the second half over a minute/mile slower than the first.

I'm sure a lot of these folks probably were hit hard by the heat and the humidity. One thing I'm going to work on is to compare these 2005 stats with those from 2004 and earlier. Also, I would like to see how paces vary based on age and sex. If you have any stats that you would like to see, feel free to leave a comment. I can't promise anything, but I can give it a try.

'Change In Pace' is the change in mintues/mile
between the first half and the second half.
Negative means faster second half.


All those who ran the marathon at all different paces.

 Change In Pace       #     %
 --------------    ----   ---
 -2:00 to -1:00       9    0%
  -1:00 to 0:00     138    3%
   0:00 to 1:00    1369   30%
   1:00 to 2:00    1403   31%
   2:00 to 3:00     890   19%
   3:00 to 4:00     477   10%
      over 4:00     290    6%
 --------------    ----   ---
          Total    4576

Those who ran the marathon in under 3 hours.

 Change In Pace       #     %
 --------------    ----   ---
  -1:00 to 0:00       3    3%
   0:00 to 1:00      96   92%
   1:00 to 2:00       4    4%
   2:00 to 3:00       1    1%
 --------------    ----   ---
          Total     104

Those who ran the marathon between 3 and 4 hours.

 Change In Pace       #     %
 --------------    ----   ---
  -1:00 to 0:00      61    5%
   0:00 to 1:00     700   54%
   1:00 to 2:00     426   33%
   2:00 to 3:00      96    7%
   3:00 to 4:00      14    1%
 --------------    ----   ---
          Total    1297

Those who ran the marathon between 4 and 5 hours.

 Change In Pace       #     %
 --------------    ----   ---
 -2:00 to -1:00       6    0%
  -1:00 to 0:00      51    3%
   0:00 to 1:00     449   23%
   1:00 to 2:00     714   37%
   2:00 to 3:00     477   24%
   3:00 to 4:00     192   10%
      over 4:00      65    3%
 --------------    ----   ---
          Total    1954

Those who ran the marathon in over 5 hours.

 Change In Pace       #     %
 --------------    ----   ---
 -2:00 to -1:00       3    0%
  -1:00 to 0:00      23    2%
   0:00 to 1:00     124   10%
   1:00 to 2:00     259   21%
   2:00 to 3:00     316   26%
   3:00 to 4:00     271   22%
      over 4:00     225   18%
 --------------    ----   ---
          Total    1221