well if birds are basket trainned as ybs they'll fair better than those that aint and those that travel better and eat and drink well will be in the running if there ability is up to it in my view you have 3 types of feed , 1st is protein which aids growth and repair , 2nd is instant energy , 3rd is stored energy such as fats , like any engine a bird has its requirements and needs to be fueled according to how many miles it would be doing , you could take the various fuels for car racing into consideration , rocket fuel for a very fast funny car a short load of fuel for a quick journey at high speed , and a formula one car loaded with fuel to cover a course but with a big difference , not a very great comparison but i hope you get my gist