Tuesday, October 1, 2013

How Not to "Pace" a Marathon in Three Simple Graphs

As the 2013 Chicago Marathon approaches, I am thinking quite a bit about my marathon pace. After running a 5k a couple of weeks ago, I was able to use the McMillan calculator to determine that my marathon pace should be about 7:13/mile, which if I run the tangents correctly, should get me a course PR (sub-3:10). Lots of coaches say that even pacing is the best way to run a marathon. However, I seem to run the fastest when I run the second half of the race faster than the first (i.e. negative splits). So, it would seem that for me to run my best on marathon day, I need to run either even or negative splits. However, looking over graphs of my paces for three of my past marathons, I have done quite the opposite. Take a look at my average mile pace for each 5k split in the following marathons:

Whoa, this one was bad. What I wouldn't have given that day
to swap the pace of the first 5k with the pace for last 5k!
When your legs aren't ready for 26.2, and you run way too fast early on,
then you'll end up walking it in (if you're lucky)!
Okay, this one isn't too bad (it was a course pr), but I wish I could
have swapped out those 7:05s for 7:17s. I might have been faster overall.
My speedy marathon starts are usually the result of early race adrenaline and being overly aggressive (i.e. not targeting a realistic race pace). The downside of running those big positive splits (besides losing gobs of time) is that the last few miles are a painful struggle and in a couple of cases, simply a death march. I have to walk and watch lots better-paced runners fly by me after I've hit the wall near the end of the race. If only I had adjusted my mile paces upward by 20 seconds in each of these three races, I could have put off "the wall" a little later or maybe entirely.

So, I guess what I'm saying is that I need to take it way easy for the first few miles of the Chicago Marathon on October 13th. I want the graphs to have a slope line going from the upper left to lower right, or just plain flat, rather than the other way around. We shall see...

8 comments:

  1. Oh, negative splits. I love the idea of it and know that I would finish so many races or long runs stronger, but it's just SO HARD to actually do! Funny enough, I think you were one of the first people to give me the advice to start out a little slower to speed up/finish stronger at the end! I suppose you could hang out with a pace group, but still, I imagine it'll be hard for you and Declan to take it easy right out of the gate.

    The only thing I can suggest if you want to help control your pace a little is to check out a site like jog.fm, find a few songs at your target "easy" pace for the first few miles, and see if that may help you get a feel for your starting pace on your last few runs before the marathon. What's funny is that I use this to help me go faster, but it may work the other way too :)

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    1. Yes, running negative splits is easier said than done! I am seriously thinking of keeping an eye on the 3:10 pace group, but not stress out if they get too far ahead of me in the first 20 miles. There will be plenty of time to catch up with them if that happens. I will consider your jog.fm idea. Since I don't race with music, I will have to hum an "easy" tune in my head to help me slow down! :)

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  2. well if you are starting with me, i'm sure I'll be slowing you down anyways! shadow 3:10 for at least half and see how you feel,
    We should aim for another fun run before the marathon to plan things out

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    1. Yeah, we need a race strategy. I am thinking about lining up behind the 3:15 pace group and hunt down 3:10 slowly to ensure negative splits. How many you running on Sunday? I have 8 penciled in.

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  3. Starting with the 3:15 group sounds smart. In my experience, you can only make one real move in a marathon (a deliberate picking up of the pace) so hold back as long as you can and enjoy that final 10K for a change (of course, I've told myself to do this a number of times and never succeeded). Good luck whichever way you decide to run!

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    1. Good thought about only making one move. If I run smart I should have an enjoyable, relaxed race (for the most part). I'd rather be the one passing runners that the one being passed. It can be quite defeating in a long race to have no juice left in the tank and watching other runners pass me by! Thanks!

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  4. I almost always start off slowly and pick up the pace for longer races. I usually start in the corrals behind my goal pace so that I don't get sucked up into everyone else speeding out at the start, and then focus on keeping my heart rate on the lower end until mile 4 (since it usually takes me until then to feel fully warmed up) and then work on building my HR. But sometimes I wonder if I start off too slowly. Looking at the Garmin data from some of my best races, my last mile is almost always the fastest, usually 30 seconds or more faster than my overall average pace. The nice thing is, I always finish feeling strong but spent.

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    1. I like your heart rate based/scientific strategy. Running by heart rate is probably a good way to go. I seem to run 75% of my workouts within or near my target heart range and the other 25% way over my target heart range. I wonder if how strong of a correlation there is to pace predictior paces and heart rates. Say my 5k predicts a pace is 7:15/mile, will I always be within my target heart rate at 7:15/mile? I guess I need to wear my heart rate monitor during the race to find out. I was hoping not to wear one, but now I am intrigues! :)

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