I get that pretty regularly and forgive me if this sounds stupid, but it's because I don't get enough sleep. I've found that getting enough sleep has been the biggest challenge in training for my first marathon.

This is actually pretty dangerous. I've gotten so sleepy that my eyes lose focus and start rolling up in my head. Tripping becomes likely not to mention the fact that often you're running in the street and there's oncoming traffic.

Get more sleep and you'll be fine.

Oh yeah, I get that all the time. For me I figure it's because I go running at 3-4:00am when most sensible people are still asleep! It seems to happen to me most often during the winter. Last year I distinctly remember thinking that curling up at the end of my neighbor's driveway and going to sleep sounded like a good idea.

I don't know that there's any way to prevent it other than getting more sleep...

I don't think lack of sleep is his problem. That would be too easy to figure out and he's had the problem for 20 years. When I get it, I don't feel tired before or after the run and I'm sure I would if sleep were the issue.

I also feel this way on occasion. It makes me feel silly but it's kinda fun. I thought it was due to sleeplessness and hard training.

Here is a different spin on what may be the problem. First of all, I too have felt so relaxed during a run that I wanted to just curl-up right then and there. It doesn't matter whether I've had 6 or 10 hrs of sleep.I also find myself during the day, even like 8:00am -9:00am. feeling so sleepy that if I happen to nod off, even for 30 seconds, I can go right into REM sleep. This I found out, is a symptom of perhaps a mild case of Narcolepsy. Haven't gone to see a Dr. yet, but am hoping to soon.

Actually, I've only ever had that "extremely sleepy" feeling once. I was starting to develop a case of conjunctivitis, but foolishly I did not take antibiotics right away.

I went on an 8 mile run, and the run was SO hard for me to do (very unusual). I just plodded along at 10 minute mile pace (pretty slow for me). It was extremely exhausting and I had never felt anything like that before. I don;t even remember what my rationale was at the time, but I went ahead and finished the run even though I felt like ****.

Sure enough, the next day I became extremely sick (cold/fever etc with full fledged pink eye), and had to take a week off.

So the moral is, if sleepiness during runs is not common for you, then when it DOES happen, STOP!!! and take those stupid antibiotics if you're sick