CHICAGO (CBS) — Approximately 4,000 triathletes were descending on Chicago, for one of the world’s largest triathlons this weekend along the lakefront.

WBBM Newsradio’s Regine Schlesinger reports Chicago is only the third American city to host the ITU World Triathlon.

Besides the 4,000 athletes who will swim, bike, and run in the race, some 75,000 spectators were expected to attend.

The course includes a 1,500-meter swim at in Monroe Harbor, followed by a 40-kilometer bike ride stretching from the Museum Campus to Lower Wacker Drive, and then a 10-kilometer run in a circuit through Grant Park. The shorter sprint course is a 750-meter swim, a 20-kilometer bike ride, and a 5-kilometer run along the same routes.

The event will be televised in more than 160 countries.

Watch & Listen LIVE