Austin middle-school teacher devises and executes Ironman route

Why he did it: "I wanted to do an Ironman, but I didn't want to travel for it," Natenberg, a sinewy, evidently indefatigable former U.S. national team ultimate frisbee player, told Axios. "I wanted a shortened timeline to train — seven weeks to minimize the impact on my family — and I wanted something really challenging, something that I could possibly fail at."

• Plus: He wanted to do something self-supported — he sketched out gas stations where he could pop in for water and food — though day-of about 20 friends and family came out to hand him food, coconut water and cold towels — crucial as temps reached 97 degrees.

Details: Natenberg, 41, who is married to another Kealing teacher (an athlete in her own right) and has two daughters (ages 6 and 3), started his day at 5am at Barton Springs for the 2.4-mile swim.

• He then hopped on his bike and headed west, on a hilly 112-mile route with a 6,500-foot gain.

• He finished the last leg, a full marathon, taking in Austin landmarks like the Capitol and UT Tower, as well as his East Austin neighborhood, by 9pm, completing each stage ahead of Ironman cut-off times.

What he's saying: "I don't need to do that again," Natenberg, known as Tank to his friends, told Axios. "I'm proud of my accomplishment and now it's on to something else."

• Natenberg is due to compete on a club ultimate team in the spring.

The bottom line: The day after his self-made Ironman circuit, Tank was back in the classroom.