, often while exercising. Now, the not-so-great news: No one really knows why, and though it’s likely an innocuous, if annoying, condition, it could be the sign of something more serious and should be checked out by your doctor. Yawning, in general, is a medical mystery. Scientists once chalked it up to your body needing more oxygen. As you take normal, shallow breaths, many of the lungs’ air sacs, or alveoli, go unused and partially collapse. The theory was that your brain would trigger a yawn to move air deep into the lungs and keep all the alveoli in use. But studies haven’t proven that theory. Even when researchers had volunteers inhale 100 percent pure oxygen, it didn’t decrease the number of yawns. Some experts believe that a yawn is your body’s way of gearing up for energetic or difficult activity. Physiologically, yawning boosts your blood pressure and your heart rate. It’s well documented that Olympic athletes often yawn before competition and paratroopers yawn before a jump. Obviously, if you’re sleep deprived, as the majority of people are, then you may just be yawning because you’re tired, especially if, as you say, you’re exercising in the morning and evening, which are common low-energy times of day. In the animal world, yawning is often a response to stress. Watch your dog. When she’s really excited, she’ll yawn a lot. Dogs use yawning as a “calming signal,” a way to tell other dogs–and people–that they’re feeling anxious and need a break. Some experts believe stress can stimulate a similar reaction in people. Finally, you can bring on a yawn just thinking about it. So if you’re obsessing about yawning, well, you’re bound to start yawning. All that said, excessive yawning is clearly not the norm. You may want to rule out the obvious first. Are you fully rested when you’re working out? If not, fatigue could be the cause. Next, consider medications. You don’t mention any, but certain drugs, particularly SSRI-class antidepressants like Prozac, can cause excessive yawning. Finally, non-stop yawning is a possible sign of an underlying vasovagal (heart rate and blood pressure) problem. So, call your doctor and set up an appointment. You can help him diagnose your condition by tracking how often you’re yawning each day, how much sleep you’re getting, and what medications (including herbs and over-the-counter drugs) you’re taking.
