Some polevaulters shave thier armpits because they thaink that it will make them run fast because of less weight. Some do it just because of religion.
Vaulters
You say, "Mom, I have hairy armpits and I need to shave them." :). Then you go buy a razor and shaving cream and you SHAVE 'EM!
they cant reach their own armpits
I don't know of any "pole volter", but of "pole vaulters", the most famous is Sergei Bubka.
French girls used not to shave their armpits, but that is centuries ago, nowadays, you'd have to go to France to check it out.
you dont
no
Yes
I believe they supply them themselves and can have up to around 3 poles each.
Every guy does it
The pole acts like a spring, that is why it bends so much at the start of the jump.
Most of them don't.