The biggest sporting event to ever hit Huntsville is taking place this Sunday.

The full-Ironman is a worldwide event as racers from all over the world will be swimming, running, and biking through different parts of town.

The race is expected to run the whole day as close to 1,300 athletes are registered. Manager Myke Malone says as every athlete crosses the finish line, there will be one thing he will be thankful for.

The swimmers kick things off early Sunday morning. Malone says the last person could be expected to cross the finish line by midnight.