Louisville, Ky. (WHAS11) - More than 2,000 athletes from around the world will begin the day with a 2.4 mile swim in the Ohio River.
The pros start their swim at 6:50 a.m.
Then everyone else begins at 7 a.m.
Afer the swim, they'll complete a 112 mile bike ride. Then a marathon, 26.2 miles.
The swim course is a point to point swim, starting with a jump into the Ohio near the Tumbleweed and finishes at the Great Lawn.
The bike course will take athletes outside of Louisville toward Oldham and Henry Counties with a loop section in La Grange.
Finally, the marathon, the last leg, takes competitors south from Waterfront Park by Churchill Downs with the turnaround near Iroquis Park.
The race officially ends at midnight. Any competitor who doesn't finish by then is marked as a non-finisher.
Massage and cool-down areas at Fourth Street Live will open this afternoon.
The pro division is expected to finish around 3 p.m.
There's an official finisher party from 10 p.m. to midnight. Help come out and cheer on the finishers.