Physical limitation? Does anyone in his right mind believe that the horses that run these fast numbers are doing it via hay, oats, water alone? Please! THEY'RE ALL STEROIDED UP THE WAZOO! [On that note, Barry Bonds hit 714 today.] And the drugs have serious contraindications that change physiology, effect bone and promote the possibility of breakdowns. Just once, I'd like someone from the established racing press to gather the lifelong detailed vet history of a few of these fast horses and correlate the month-by-month injections to the performance figures. Fat chance.