Although she is usually not overly concerned with her race time, Walker keeps a mental tally of the dogs she pets each race – her record is 67 pets.

“They’re like my aid station,” Walker, who lives in Tampa, told The Washington Post. “If I feel like I’m running slow, and I’m just like, ‘Ugh, I don’t feel like running anymore,’ then I see a dog and I’m petting them, and I start running again, and my pace is so much faster.”

Walker completed her first Ironman in Panama City Beach, Florida, in November 2007. She began competing alongside her eventual husband, Dougin Walker, after they met at a triathlon in Tuscaloosa, Alabama, in 2010.

But Jill Walker didn’t think about completing 100 races until 2018, when her friend Tom Kennedy suggested she reach the milestone. At that point, Walker had finished about 25 Ironmans but was still as energetic as ever on race days, waking Dougin in bed in the mornings so he would get ready.

As Walker competed in double-digit Ironmans in recent years, she raised the bar for the number of dogs she patted.

Walker said she and her family have always owned dogs, and she has four Australian shepherds now: Kona, 12, who’s named after the Ironman World Championship in Kailua-Kona, Hawaii; Maverick, 6; Rinny, 5, who received her name from professional triathlete Mirinda Carfrae’s nickname; and Eiko, an 11-month-old named after a triathlete Walker met at an Ironman in Busselton, Australia, in December 2022.

During races, Walker said, she always stops when she sees Australian shepherds or Bernese mountain dogs (she adopted a Bernese mountain dog and Australian shepherd mix named Balian in 2016).

While competing in an Ironman in Lake Placid, New York, in July 2022, she stopped to pet two Bernese mountain dogs. When Walker returned to the competition the next year, the dogs’ owner stood in the same spot and recognised Walker, who pet the dogs again.

The running portion of an Ironman in Kalmar, Sweden, in August 2022 consisted of running the same loop three times. Walker said the route maximised her “dpm,” a term she coined for dogs per mile. After she met four dogs on the first loop, the owners tracked Walker online by her bib number, 161, to ensure she could pet them on each lap.

Walker’s record of 67 pets came in Vitoria-Gasteiz, Spain, in July 2023. Dougin, 60, calculated her dpm during the running portion to be an impressive two-and-a-half dogs per mile (1.6km).

Walker spends about 30 seconds with each dog, she said. Her best time was 11 hours and 21 minutes at an Ironman in Tempe, Arizona, in November 2015, but when she stops for pets, she usually finishes in between 12 and 15 hours.

Walker said she’s used to people’s confused looks and questions when she stops to pet their dogs, including “shouldn’t you be running?” Sometimes on hot days, she’ll carry ice from an aid station to toss to a dog on the side of the course.

Last month, Dougin stood off course next to a Labradoodle during a race in Conway, New Hampshire, because he figured his wife would stop there. She did – and didn’t notice her husband until after she pet the dog.

Walker’s mid-race ideas haven’t been limited to dogs, though.

She and Dougin hired a wedding planner and an officiant for a wedding ceremony on a triathlon’s bike course in Cozumel, Mexico, in November 2022. After biking one loop, they stopped at the Cozumel Palace, the hotel where they were staying, and kissed in their cycling shoes and short tights among pink rose petals scattered on the ground.

Jill Walker wore a pink shirt with a flowery pattern, mimicking a wedding gown, and Dougin Walker donned a black shirt with a tuxedo design on the front. Jill’s friend even found someone nearby walking an Austrian shepherd and asked if Jill could take a photo with the dog at the ceremony.

About 30 minutes after beginning the ceremony, the couple returned to their Trek bikes. The wedding planner taped signs to the back of their shirts that said “JUST MARRIED,” including colourful ribbons on the bottom that swayed as they rode. Jill Walker zip-tied a white veil on to the back of her white biking helmet and one on to the back of the white visor she ran in.

For Walker’s 100th Ironman in Panama City Beach in November, dozens of family members and friends will compete alongside her. She’s even encouraging strangers to join her. She ordered 100 blue bandannas that say “100” – with paws inside the zeros – that she hopes to distribute to dogs along the course.

She’ll wear a blue and black one-piece that shows a picture of her four Australian shepherds on the back. Three spots on the uniform list the routine Walker will complete for the 100th time: “SWIM. BIKE. RUN. PET. FINISH.”