Endurance Induced Insomnia

Have you ever finished a tough race or a training day, 

come to the that "bed time" time of day 

and find yourself completely unable to get to sleep?

Well, after my 20 mile run on Saturday, that's exactly where I found myself.  I came home around 5PM, took my post-race snacks, showered, ate, and then laid down hoping that doing a bit of reading would put me to sleep for a couple hours.  I usually read 3-4 chapters of a book before going to bed every night and it winds me down very easily.  About 10 chapters later I realized that this wasn't going to work. 

I put on a movie thinking that might work.  Nope.

I went back to reading.  Nothing.  I even finished the book (Digital Fortress - great read!)

Around 1AM in the morning I went and made some more food thinking my body was still craving nutrients. I don't know if that was it or what, but the next thing I remember I was turning off my alarm at 5:40AM and getting up for work.

It's weird that despite being up late and waking up early, I didn't feel an ounce of sleep deprivation.  Did my body simply fall into a deeper sleep and get all the rest it needed?  I've heard that Dean Karnazes sleeps something like 4 hours a night and attributes it to deeper sleeping because of his fitness level.  

I did a Google search and most of what I found fell into advice for normal insomnia, iron deficiency issues, late night/off schedule running, and such.  I never have an issue sleeping, I'm pretty sure my iron is ok since I take my vitamin religiously and also took one before AND after my run, and I was done running well before bed time.  So what gives?

Finally I stumbled upon a thread that touched on the idea of hormones.  As a science geek, my ears perked!  I think we can all agree that during extended exercise, it makes sense that our bodies are pumping some extra hormones around.  One hormone they mentioned was Cortisol, a hormone which has many roles in the body including stress responses as well as influencing our circadian rhythms (sleep/wake cycles).  As a science geek, I find this very interesting.

So...is it my body reacting to the stress of the run and releasing a bunch of extra hormones that are keeping me awake?  If it doesn't affect my sense of being rested after sleep, is this a free ticket to more training, less sleep?  Or is this something completely different?  Whatever it is, it has a definite pattern.

After my rest day yesterday, I had a completely normal night of sleep.  My scientific mind says that points directly to the run.  Additionally, the same episode of insomnia happened at both Ironman 70.3 Rhode Island and Vegas.  However, after my Sprints and Oly's last year, I would fall asleep easily.  There's definitely a threshold somewhere in either the distance, time, or the expended energy.

Has this ever happened to you?

Any ideas on what this could be?

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Questions

1.  Have you ever experienced insomnia after a race or tough training day?

2.  Any thoughts (or votes) on what might be causing the insomnia?


Stay fit.  Stay healthy.  Stay safe.