I noticed while looking at the London press materials that Meb and Ritz will both be wearing USA singlets, which I've seen them both do before. Hall wore his Asics singlet at Boston, but I've seen Meb wear USA at Boston. He doesn't ever seem to wear USA at half marathons/15ks, however. My question is, how is it determined what the runner is going to wear? Is it simply a matter of personal preference for that runner? Do they need some sort of okay from USATF? It seems obvious that a particular runner would need to have represented the US in an official championship event already. Does Ryan forgo wearing the USA simply because it's a Nike singlet? Same with Brian Sell?
I've also noticed a similar thing with international runners. Lel has worn his Kenya singlet at London in the past, but has been wearing a more generic Nike team singlet more recently.