Open hand or closed Fist sprinting

How do you guys prefer to sprint? with your hands spread open or clinched into a fist?

What are the benefits and disadvantages of these styles and does it effect your ability to push,relax, accelerate etc…

http://www.charliefrancis.com/community/viewthread.php?tid=1885

Kweli, how did u do this season?

I was always taught that your hands should be relaxed.

I have seen athletes with both closed & open hands look like they are about to hit/slap somebody-hands are so tight.

I run with hands closed but relaxed. How I have don’t it for years.