I wear shoes alot and it helps some... shoes should be banned.
It might just be thought effecting your times. You think "Coca Cola makes me do better", and it can actually make you perform better, not the Coca Cola.
No, but I've held competitions where food and drink have been banned in the venue. This makes breaks and lunch time important features of the schedule.
It's also nice when competitors aren't spilling slushies everywhere...