(CBS) — The Chicago Marathon is still two weeks away, but thousands of runners raced along the southern part Lake Shore Drive Sunday morning, reports WBBM’s Nancy Harty.

The Chicago Half Marathon is in its 19th year and it provides a final tune-up for some runners doing the full 26.2 miles, says spokesman Scott Hutmacher.

“It gives them an idea to go through race day conditions,” he said. “Using aid stations, going through the gear check process, resting well in advance and eating well before the race, so this is their final tune-up before the big Chicago Marathon in two weeks.”

Starting and finishing in Jackson Park provides a different view of the city for 12,000 runners. Hutmacher says 36 countries and 48 states are represented.

Hutmacher says while the marathon attracts more than three times that many runners, the distance is the most popular in the country and his calls Chicago’s version the pinnacle of middle distance races.