"Leo, a big yawn to get as much oxygen into the system as possible"

I don't think that it is a matter of getting as much oxygen as possible as it is to help him relax during a very tense moment (the lead up to the start). There is a lot of anxiety going through those athletes especially since they have to stand there and listen to one another get introduced and it gives them time to let their mind begin to worry. A yawn for Leo might just be a way to manage the anxiety to center himself before starting.

This past Winter Olympics (and the last 2) Apolo Ono is notorious for doing that to 1) Calm himself and 2) To fake out his opponents that he is tired.

thats why you yawn when sleepy. to get as much oxygen to awake the brain.

you don't have to cover your mouth. no evil spirits will wonder in.

I remember hearing about how Apollo does that. but personally, I will sometimes yawn when I'm really nervous before a big race (I don't know why, it just happens). Are these guys embarrassed to admit that they're nervous, or is there really something else behind it?

don't be silly. no, that has no significant bearing on the percentage of o2 within "the system".

I always cough before the start of a race.

Get them lungs ready for some serious punishment.

actually, i doubt toni understands the physiology of it but it was actually a true statement.

when you breathe, you only bring in around 60-80% of your maximal inspiratory volume. yawning often brings this up closer to 80-90%. that said, just walking around we'll feel just fine breathing in 50-60% of our max. there's a reason that it "feels good" to yawn, thats pretty much it, the improved alertness that comes from a rush of higher o2 concentraion/volume.

Look up the sympathetic/parasympathetic 'yo-yo' effect with your nervous system. It's your fight or flight reaction when you are under stress.

Yawning can help bring the two back into line when you cranking the stress side (sympathetic) a little too much.

Yawning (and it is not a real yawn, it is a fake yawn) is done for one reason and one reason only. It is your way of trying to convince yourself and those around you that you are relaxed and feeling no pressure. When in reality you are a bundle of nerves, and a real yawn is the last thing your system could actually do.

Everyone is wrong on this one.

A big yawn stretches your type II alveolar cells and stimulates them to secrete more surfactant (think detergent). This lowers the surface tension of the water on your alveoli, makes it easier for you to inflate your lungs (alveoli) and thus increases gas exchange.

This one has to be right:

North Coast wrote:

It's your fight or flight reaction when you are under stress.

It's subconscious. I always yawn at the starting line, too.

View some of the older youtube racing videos. You be surprised how many people yawn on the starting line.

shortshorts wrote:

Everyone is wrong on this one.

A big yawn stretches your type II alveolar cells and stimulates them to secrete more surfactant (think detergent). This lowers the surface tension of the water on your alveoli, makes it easier for you to inflate your lungs (alveoli) and thus increases gas exchange.

Please back this up with data.

shortshorts wrote:

Everyone is wrong on this one.

A big yawn stretches your type II alveolar cells and stimulates them to secrete more surfactant (think detergent). This lowers the surface tension of the water on your alveoli, makes it easier for you to inflate your lungs (alveoli) and thus increases gas exchange.

This is actually correct, or at least most likely to be correct. (It has yet to be proven, but by an large this is the most widely excepted theory).

Source: Not going to waste my time linking articles that no one here would read. Take it or leave it, but this is the most widely held theory.

80% of people reading this thread have already yawned by the time they reach this post.

i always yawn a lot before races. its a nervous thing for me i think

Who yawns when they're nervous? Most people breathe less when they're nervous.

El Mastero wrote:

shortshorts wrote:

Everyone is wrong on this one.

A big yawn stretches your type II alveolar cells and stimulates them to secrete more surfactant (think detergent). This lowers the surface tension of the water on your alveoli, makes it easier for you to inflate your lungs (alveoli) and thus increases gas exchange.

Please back this up with data.

Just because I am bored and putting off doing homework.

Sorry for no full text link. Science is pretty reputable, right?

Michael Scott wrote:

Who yawns when they're nervous?

i just told you- i yawn when im nervous. not too bright are you?

MedSchoolRunner wrote:

(It has yet to be proven, but by an large this is the most widely excepted theory).

Hey MedSchool, I think you have to repeat grade school English...

It's "accepted", not "excepted".