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Yawning O:

Fun facts: An average yawn lasts 6 seconds but increases your heartbeat by 30%

So, what exactly is yawning

yawningpresent participle of yawn (Verb)

1. Involuntarily open one's mouth wide and inhale deeply due to tiredness or boredom.

2. Be wide open

 What causes yawning?

The 4 popular theories:

• The physiological theory: Our bodies induce yawning to draw in more oxygen or remove a buildup of carbon dioxide. This theory helps explain why we yawn in groups. Larger groups produce more carbon dioxide, which means our bodies would act to draw in more oxygen and get rid of the excess carbon dioxide. However, if our bodies make us yawn to draw in needed oxygen, wouldn't we yawn during exercise? Robert Provine, a developmental neuroscientist at the University of Maryland, Baltimore County and a leading expert on yawning, has tested this theory: Giving people additional oxygen didn't decrease yawning, and decreasing the amount of carbon dioxide in a subject's environment also didn't prevent yawning [source: University of Washington].
• The evolution theory: Some think that yawning began with our ancestors, who used yawning to show their teeth and intimidate others. An offshoot of this theory is the idea that yawning developed from early man as a signal for us to change activities [source: University of Washington].
• The boredom theory: Although we do tend to yawn when bored or tired, this theory doesn't explain why Olympic athletes yawn right before they compete in their event or why dogs tend to yawn just before they attack. It's doubtful either is bored [source: Patterson].
• The brain-cooling theory: A more recent theory proposed by researchers is that since people yawn more in situations where their brains are likely to be warmer -- tested by having some subjects breathe through their noses or press hot or cold packs to their foreheads -- it's a way to cool down their brains. What does it matter if our brains are cold or hot? Cool brains can think more clearly; hence, yawning might have developed to keep us alert [source: Nagourney].

So is yawning good or bad?

In the book entitled "How God Changes Your Brain: Breakthrough Findings from a Leading Neuroscientist”.  The author lists 8 activites which can help to enhance brain health and the 5th one is yawning. Here are some examples of how it does:

1)   Stimulates alertness and concentration
2)   Optimizes brain activity and metabolism
3)   Improves cognitive function
4)   Improve memory recall
5)   Enhances consciousness and introspection
6)   Lowers stress
7)   Relaxes every part of your body
8)   Improves voluntary muscle control
9)   Enhances athletic skills
10) Fine-tunes your sense of time
11) Increases empathy and social awareness
12) Enhances pleasure and sensuality

yawning - bad?

Yawning is a normal response to fatigue and drowsiness, but excessive yawning can be caused by a vasovagal reaction. This reaction is caused by the action of a nerve, called the vagus nerve, on the blood vessels. It may indicate a heart problem.

On the overall, yawning might not be necessarily be bad.

Sources:

• http://www.onlinebraingamesblog.com/brain-fitness/yawning-can-improve-memory-brain-fitness-and-overall-brain-health
• http://www.google.com.sg/search?q=whats+yawning&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-GB:official&client=firefox-a&safe=active
• http://en.wikipedia.org/wiki/Yawning
• http://reallyworks.org/blog/2009/01/29/what-causes-yawning-the-real-reason-why-people-yawn/
• http://answers.yahoo.com/question/index?qid=20070815193955AAFrci6
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• http://www.nlm.nih.gov/medlineplus/ency/article/003096.htm