17 Miles! (And Some Interesting Science About Long Runs)
On Saturday I did the unthinkable and got up at 4:15am to get ready for a MORNING long run. I am so not cut out to be an early riser.
My pace was a good 15 seconds slower than normal for the first 7-ish miles because my body was in total shock that it wasn’t just dreaming that I was running.
But guess what???? I MADE IT 17 MILES!
And guess what else???? It was way easier than when I did 16 miles and had a crappy finish!
My legs were definitely sore by the end, but thanks to eating more chomps than usual I finished with energy still left in the tank.
On Thursday I was talking to my coach about the rest of my marathon training plan. We started talking about what the longest run I would do will be.
My coach mentioned that I could top out at just 18-miles for a long run, though I said I would prefer 20 miles. Why only 18? As it turns out, any long run over 2.5 hours provides more mental training than any physical benefit.
“Research has shown that your body doesn’t see a significant increase in aerobic development, specifically mitochondial development, when running over 90 minutes. The majority of physiological stimulus of long runs occurs between the 60 and 90 minute mark. That means after running for 3 hours, aerobic benefits aren’t markedly better than when you run for only 2 hours.” (Competitor)
If this is true, why do most people run 20 and 22-milers as part of marathon training?
“The foundation of marathon training still comes from the 1970s and 1980s at the beginning of the running boom. Marathoning hadn’t quite hit the numbers it has today, and the average finishing time at most races was closer to 3 hours. As such the basis for how to train for a marathon came from runners who averaged close to 6 minutes per mile for the entire race. Therefore, 20 and 22 milers were common for these athletes as a run of this distance would only take them about 2.5 hours to finish at an easy pace.” (Competitor)
According to Marathon Nation and multiple other sources, this is why splitting up a long run (or simply not running more than 2.5 hours) during marathon training can be beneficial for slower runners.
Most of the things that I read seem to suggest that it’s better to focus on shorter runs during the week that work to increase your aerobic base rather than focusing on running for many hours just to reach the proverbial 22-miler.
Basically, focusing on shorter, high-intensity runs during the week will help a runner get faster and also allow a runner to train on fatigued legs more often which simulates the late-race feeling. This helps the runner build up mental strength when it comes to fighting off the “I’m sore, I just want to stop” feeling.
I thought all that research was really fascinating! (Although I still intend to run a 20-miler).
Cheryl has been using split runs for the marathon training cycle she is in now, and I will be so interested to see what she thinks about it after running her marathon. (She’s not doing it because she is a slower runner, but rather for other benefits).
I’ll definitely be keeping this split idea in mind for when I start 50K training. I had noticed that a few elite ultrarunners do two-a-days in training and I assumed that it was just because they like running so much, but maybe it’s for similar reasons.
It makes sense that running on fatigued legs from the morning would benefit them for the later stages in an ultra race, especially if simply running longer in the morning isn’t providing them additional aerobic benefit.
Have you ever split up a long run?
What is the longest you like to run during marathon training?