The Woodlands' Ironman draw 3,000 athletes

Supporters pose for a photograph at the 2018 Memorial Hermann IRONMAN® North American Championship Texas Triathlon on The Woodlands Waterway on Saturday, April 28, 2018, in The Woodlands. The IRONMAN features 2.4 miles of swimming, 112 miles of biking and 26.2 miles of running. less Supporters pose for a photograph at the 2018 Memorial Hermann IRONMAN® North American Championship Texas Triathlon on The Woodlands Waterway on Saturday, April 28, 2018, in The Woodlands. The IRONMAN features ... more Photo: Yi-Chin Lee, Houston Chronicle Photo: Yi-Chin Lee, Houston Chronicle Image 1 of / 108 Caption Close The Woodlands' Ironman draw 3,000 athletes 1 / 108 Back to Gallery

Nearly 3,000 athletes from across the country and world are in The Woodlands this weekend for the Ironman triathlon.

Racers began with a swim from North Shore Park to the canal at Town Green Park at 6:30 a.m. Saturday. They then bike through The Woodlands and Northern Harris County, including on two loops on the Hardy Toll Road.

Participants run 26.2 miles through The Woodlands toward the finish line on Waterway Avenue. The top runners are expected to arrive there around 2 p.m., with the last racers expected around midnight.

Among the racers this year will be Marcus Cook, a 45-year-old Houston native who lost 256 pounds through a gastric bypass, and changes to his exercise and diet. Cook said he was inspired to become more healthy after watching his friend die of cancer.

"Before he died, he said 'I'm dying because I have an incurable disease, and you're dying because you have a choice,' " Cook wrote in his biography for the race.

Here are the best places to watch the race, according to Ironman officials:

Swim: Along the Lake Woodlands Pkwy Bridge just East of North Shore Park. Also, along the canal between Lake Woodlands and the swim finish (best accessed from the stairs down to the waterway off Grogan's Mill).

Bike: The streets and neighborhoods are heavily congested during the bike portion of the event. In order to avoid getting stuck out on the course, the best option for the bike start and finish is along Lake Robbins.

Run: Along the waterway (3 loop course), especially near the restaurants close to Waterway Ave and near the transition area. No tents are per­mitted on the waterway; however, North Shore Park is a good place for families/kids mid-day.