I was comparing the paces from my three fastest marathons and I noticed a trend:
In all three marathons there was a consistent increase in pace per mile starting right after mile 15:
During all three marathons, between miles 16 and 24, my speed gradually got slower until mile 24. At mile 24 I start to "kick" and use up any energy reserves, hence the faster paces for 24 through 26.2. This chart shows that I always seem to start slightly sucking wind at right around mile 16. This is the point where my race should actually start, however in each case I started to slowly to lose ground.I'm not quite "hitting the wall" at mile 16, but this upward trajectory is a tell-tale indicator that I need to figure out how to stay strong through mile 24 when my kick starts. I am guessing one thing I need to NOT do is to increase my speed dramatically after mile 13, which is what I think I have done in the past (consciously or unconsciously).
Just curious...do you think it has anything to do with that fact that you don't do longer runs than 16-18? Supposedly, it doesn't make a difference. I'm wondering what the science is here...looks like I have something to research for a blog post after the marathon!
ReplyDelete~Wendy
Good observation! When I wrote this post, I also thought about the 16 mile long run as a reason I'm not able to hold pace past mile 16 since they are the same number. But I'm guessing (hoping?) that it has more to do with when I choose to increase in my pace at mile 13. I guess subconsciously, I say to myself: "Halfway done, now let's see what these legs can do", then I speed up, but I speed up too quickly and start to fatigue after 3 miles. Then I slowly pay for my "mini surge" from miles 16 to 24 via slower paces. If I eliminate the "surge" I can hopefully save my legs some fatigue until much later.
DeleteInteresting, because I always though negative splits were the way to go, but the more I read, it looks like keeping a steady pace=success. That's my plan for this marathon, but we'll see since I've turned everything upside down this time!
Delete~wendy
Yes, after several years of positive splitting, I am a pretty good negative splitter now - in all distances except in the marathon. Maybe the steady pace = success way is the way to go. I am seriously thinking about hooking up with a pace group and try learn what a even-paced marathon feels like. :)
DeleteThis is such a cool analysis. Thinking back to the marathons I actually raced, my fade came at 19 and 17. The early fade was due to going out waaaay to fast. Live and learn.
ReplyDeleteYes, going out too fast is another nemesis of mine. You can see that during my three marathons in the chart that I start with relatively slow miles, but maybe: 1) They are not slow enough or 2) I don't run enough slow miles in the beginning. I am hoping to figure out the right balance before October 12!
DeleteYes, the chart is a useful reality check of how I really run marathons. Sometimes, it's better to get a dose of cold, hard reality than pull some "pie-in-the-sky" split chart out of thin air that doesn't fit my style of running. Hoping to make the incline on the right hand side of the chart a decline!
ReplyDeleteWhat a terrific analysis! Wendy's observation is spot-on, too. I think analyses like these are the reason that you have had so much success with your training, because you know exactly where to focus for improvement.
ReplyDeleteI do tend to want to try to speed up at the halfway point of a race, myself. I've become so focused on negative splits. Frequently the recommended strategy is to take things comfortably for the first half and then start speeding up for the second half. But then, I always tend to hit a mental wall around the last quarter of the race (e.g. mile 10 or 11 in a half marathon, mile 8 in a 10-miler)!
Thanks. I hope my analysis leads me to the right path/pace for the marathon! My mental wall says "go! go! go!" instead of "go just a little faster" after mile 13 . That is, I "put my foot on the gas" too much and try to make up for lost time all at once shortly after the halfway mark. What would be better would be to speed up only a few seconds per mile after 13. For example: If I'm running consistent 7:10s for the first half of the race, I then need to make my splits for 14, 15, 16, 17 something like 7:05, 7:00, 6:55, 6:55 instead of 6:50, 6:50, 6:50, 7:10+. So, my focus will need to be: Do nice and easy increases in speed in the middle of the race. There are still plenty of miles left at that point to get back to my goal pace! We'll see if I can stick to my plan!
DeleteInteresting analysis! I really love charts. I think that looking at the data from your past races and understanding what you did then and what you can improve on for the Chicago Marathon will really help your performance on race day. I totally crashed around mile 16 at the Fox Valley Marathon--there must be something about that distance!
ReplyDeleteThanks! I hope some good comes of this and I don't end up throwing it all out the window once the starting gun fires next Sunday. Sorry to hear about crashing at mile 16. There is definitely something that happens then. :)
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