Strange issue, YAWNING during workouts!

I'm another one that yawns during work outs. I never saw it as a particular problem since yawns are supposed to mean that your system is seeking more oxygen than it's getting, and it was never accompanied by anything concerning.

You yawn when your body is trying to get more oxygen, focus on you breathing more and try to keep it regular.
I used to have the same thing happen to me, I would hold my breath a lot during a workout and that resulted in a lot of yawning!

It seems to me that the information regarding this phenomena is not very credible or convincing. Lack of oxygen (O2/CO2 regulation), is a very problematic explanation. People traveling from lower to higher altitudes dont spontaneously yawn, (though I am sure there are anecdotal experiences to the contrary). Next time you have a lay over at Stapleton Int'l, take a look around you and see if everyone getting off the airplanes is spontaneously yawning. Same problem is also true with the idea that yawning is way of cooling the brain. If you get off the plane in Phoenix in July when its 118 degrees, tell me that everyone is yawning incessantly and cant help themselves as their bodies try to cool down their brains. So to prevent yourself from yawning during exercise, you put an ice pack on your head? Yea, try that!! (Well, you might not yawn, but that would be for other reasons....that is, you could put an ice pack, bengay, or even a heat pack anywhere on your body and you probably wouldnt yawn!).

My own experience is something a little different. My sense is that exercise is affecting dopamine, seratonin levels and the general chemistry of the brain. My own hypothesis is that there is a transition period where the body (and the brain) is going from a relatively at rest chemistry to an active chemistry (and vice versa). During these transition periods, (regardless of whether the transition is to a higher or a lower state), the resulting chemical state within the brain triggers the yawning response as a type of motor stimulus "wake up" call.

I havent done any research on this, but, my own experience is that the yawning doesnt immediately begin when I start exercising. When it does begin after about 5 mins or so, it will last for about 20 mins. It then begins to wain to the point where it is stops after about 30 - 45 mins even if my activity level remains high for several hours (skiing, backpacking, cycling, kayaking). My guess is that folks that have low dopamine and seratonin levels will tend to yawn more than individuals who have normal levels, but it is just as likely that the yawn stimulus is due to some other chemical effect occuring in the brain during these transition periods. That is, those who find themselves relaxed and calm after taking a small amount of a stimulant (or brief exercise), are more likely to yawn than those who feel edgy when they take a stimulant. (Most people will experience a general feeling of physical well being after exercise but not everyone will have a feeling of mental calm)

If a yawn is a motor stimulus whereby the brain can mechanically stimulate itself to "wake up" as a result of a chemical state affecting the brain, (like wiping your face and neck with a damp towel...if you will), it would seem to potentially account for the different circumstances where people tend to yawn. (Of course, the most inexplicable thing about yawning is that it does seem to be contagious. Its such a strange physiological characteristic.)