OK, did a web search on this race, it does start at 7 am. The winner will take less than 20 minutes to complete the course, the walkers about 45 minutes. (I have been a runner over 20 years - lots of experience in this area!), so if Epcot opens at 9:00, there will probably be minimal impact. Believe me, even large races have much less participants than your daily guests at Disney! And I had not previously heard of this race and live only an hour away, and cannot find much more info besides what time it starts, so outsite of the Orlando area it is probably not that well known of. If you plan to go in first thing in the morning and drive, that is probably the only encounter with the race you would have. I do know that participants do NOT get tickets with their race fee, so once they run, most will probably leave.