Intense Extended Exercise Makes Me Sleepy

February 21, 2006 7:14 AM

Intense Extended Exercise Makes Me Sleepy Why?

I am a little overweight and starting to get active again. I started a workout routine yesterday and pushed a little too hard which resulted in my getting intensely sleepy. This isn't the first time I've experienced it. I was breathing hard, and had been for a while, but not struggling to get air. It seems like oxygen deprivation might be the culprit but I havn't heard of this happening before. Any one else heard of or experienced this before and have an idea of what it is?

Thanks!

Wong

posted by Wong Fei-hung to health & fitness (13 comments total)

Good job! It means you worked yourself hard and your body wants to rest. It's a good thing. This happens to me all the time after intense workouts.
posted by schroedinger at 7:26 AM on February 21, 2006

[fixed post title, first line of post]
posted by jessamyn at 7:28 AM on February 21, 2006

Hmm, I've never really gotten "sleepy" after working out, but I wouldn't worry about it.
posted by delmoi at 7:31 AM on February 21, 2006

Did you get sleepy while you were still exercising hard (how I read your post), or after you were done (how other people seem to have read it)?
posted by crabintheocean at 7:41 AM on February 21, 2006

Oops - thanks for the clarifying question. I started getting sleepy after completing about 60% of the workout. I persisted for about 4 more exercises and stopped when the sleepiness increased.

Today I just worked on trying to complete the entire workout and without pushing myself, maintaining even breathing, and didn't have the sleepiness symptom at all.

(Thanks for Fixing the title Jess!)
posted by Wong Fei-hung at 7:52 AM on February 21, 2006

My workouts used to wipe me out, because I was pushing far too hard. Predictably, I got tired of being tired, and quit.

I've had much more success with a workout suited to my fitness level, and not a bit more.

Take it a little easier. Your workouts should give you energy, not take it away.
posted by frykitty at 7:54 AM on February 21, 2006

How do you feel 20-50 minutes after you end the workout? Do you eat immediately after?
posted by mhuckaba at 7:59 AM on February 21, 2006

Yesterday I felt the sleepiness effect during/after the workout but don't recall feeling it 30-40 minutes afterwords. Breakfast happened about 45 minutes after the workout.

Today I followed the same eating pattern. Physically I felt fine after both workouts. I was never "shaky" or "trembly".
posted by Wong Fei-hung at 8:24 AM on February 21, 2006

Another anecdote: I started working out again a year ago, and have been pretty consistent. When I first started up again, I would get really hungry, and then sleepy - very sleepy- afterwards. After a few months of this, that effect faded away, and I don't get noticeably 'sleepy' anymore. I do, however, have an easier time sleeping.

It's probably normal, just your body getting used to doing extra work. Of course, especially if you're starting a new workout program and you're overweight, it wouldn't hurt getting a checkup and discussing this with an actual doctor.
posted by jeff-o-matic at 9:07 AM on February 21, 2006

Thanks Jeff! "See a Doctor" is never bad advice.
posted by Wong Fei-hung at 9:59 AM on February 21, 2006

Is this an aerobic or anaerobic workout? How long into it do you start to feel sleepy?

Could be your body switching from glycogen to fat. For people new to exercise, this generally feels like they're hitting a wall.

See http://www.faqs.org/faqs/misc-fitness/part1/ (particularly the graph in question 4.)

It also could be bonking (running out of enough carbs for your brain to function) but this usually takes a fairly long workout.
posted by justkevin at 10:09 AM on February 21, 2006

It was a light weight circuit work out with very little time between exercises.

I started to feel sleepy 35-40 minutes into it.

Sleepy = mentally foggy + lots of yawning + feeling that I was going to fall asleep
posted by Wong Fei-hung at 12:13 PM on February 21, 2006

Well, you mentioned you exercised before breakfast. This is good. Your body will burn up any excess carbs on the weight circuit and then if you do cardio, it will burn fat.

Do you eventually do cardio? If so you should feel your energy pop back up.

You're probably spending too much time doing low weight reps, when you should be doing higher weight exercises to start building muscle. You should AIM for 2-4 reps, and maybe 2-3 sets of those 2-4 and you're spent.
posted by mhuckaba at 1:29 PM on February 21, 2006