The defending world champion will compete at Ironman Switzerland with the goal of validating her spot on October's Ironman World Championship start line.

One week after winning the Challenge Roth title, 2015 Ironman world champion Daniela Ryf will compete in another iron-distance triathlon—this time with the goal of validating her spot on October’s Ironman World Championship start line.

The 29-year-old competed at July 3’s Ironman European Championships in Frankfurt, Germany, but struggled with the conditions and had to pull out of the race early on the bike.

“Yeah, the water itself wasn’t so crazy, but I think the problem was I really underestimated the temperature difference, so the air was quite cold,” Ryf told Triathlete.com about her Frankfurt performance. “I don’t know if it was just a day where it was hard for my body, but it was definitely hard conditions. In the swim I felt good until maybe 1500-1800 meters, and then it really just started to get me and I knew I had to go quick so I could get out. I’ve never experienced something like this, where you’re kind of starting to—not hallucinate, but everything is in slow motion. That’s how it felt. On the bike too, I pedaled in slow motion! And I tried; I really wanted to finish that race. That was the most important thing, also for the Kona qualification. And to have a DNF is never great.”

Ryf turned lemons into lemonade with a last-minute decision to compete at the iconic Challenge Roth triathlon. She dominated that race to take the victory in 8:22:04. Though Ryf technically completed the 140.6 miles, only a finish at an Ironman event will “validate” her Kona spot. To get that validation before the July qualifying cutoff (which is this weekend), she has chosen to compete at her home country’s Ironman Switzerland in Zurich—a race she won in 2014—this Sunday, July 24.

She chatted with Triathlete.com a little bit about the back-to-back attempt in the lead-up to Challenge Roth, saying “so if I survive these two races—Roth and Zurich—that will make me stronger for Kona. If I’m not able to finish Zurich, then I might have to find other races than Kona!”

Though Ryf will simply need to cross the finish line before the 16-hour cutoff, the triathlon world will be watching closely to see if the reigning world champion will ensure her starting spot. This race isn’t technically her last shot—the final cutoff is Aug. 21—but she implies that she wouldn’t do another Ironman.

RELATED PHOTOS: 2016 Challenge Roth Pro Race