It’s not from boredom or exercise fatigue.
Some days it could be related to energy levels, amount of sleep, and what time of day it is.
Most of the time it seems there is no reason to be yawning.
I’ve looked up this phenomenon and have found that no one knows for sure why some people yawn during exercise.
I think we yawn during exercise for the same reasons we yawn when we are tired.
Our brains and muscles are seeking more oxygen.
When we are tired and our body systems are trying to slow down and go into sleep mode, we start yawning because the extra burst of oxygen peps us up slightly, compensating for the systems slowing down.
When exercising, our muscles and brains are using an increased amount of oxygen, and there is also adrenaline and other fun chemicals being released that kick us into GO mode. Increasing the supply of oxygen is key to making the body perform and respond to mental and physical demands.
The body doesn’t know you are swinging bell in a studio. For all it knows you are running away from a bear in the wild! Either way, your body is going do whatever it can to see you through the period of exertion.
This all ties in to the importance of learning how to breathe while exercising.
Breathe out when you exert your muscles, and breathe in during the other times.
For example, while squatting you will want to breathe in on the way down, and breathe out as your push up with your legs and hips.
This also help protect against hernias, but that’s another blog entry all together.
*YAWN*, oh my, talking about yawns makes me yawn.