The Chicago Triathlon canceled its swim portion Sunday due to “unfavorable” beach conditions.

The National Weather Service issued a beach hazard statement for northern and central Cook County and Lake County warning of waves of 3 to 6 feet and “life-threatening currents” that could lead to unsafe swimming conditions. The weather service recommended staying out of the water and not going onto piers, breakwalls or other shoreline structures.

The warning was in effect until 3 p.m., well past the start time for the swim portion of the triathlon. The swim portion was also canceled in 2019 because of unsafe conditions.

Instead of swimming, participants could compete in the duathlon — or run-bike-run option — beginning at the swim start area on the lakefront path next to DuSable Lake Shore Drive and Balbo Avenue, according to organizers. Runners would then go 0.75 miles to the transition area to grab their bikes before heading to their respective courses.

The international distance participants were set to start at about 6 a.m., with the sprint distance participants beginning at 8:10 a.m.

Thousands of athletes were expected to compete in Sunday’s duathlon, normally a 0.93-mile swim, a 24.8-mile bike and a 6.2-mile run, with the sprint roughly half that. The bike portion of the race shuts down Lower Wacker and southbound lanes of DuSable Lake Shore Drive.