Knighton-Slatter is competing in her 50th triathlon—her fifth Ironman—on her 50th birthday.
A former couch potato, Knighton-Slatter is poised for her big Florida Five-O day.
"I want to hear, 'Brenda, you are an Ironman,' " Knighton-Slatter said about what she considers to be the perfect ending to her birthday party and milestone achievement.
Living in Illinois in 2000, Knighton-Slatter decided to get off the couch.
"It was just before I turned 40, and I was overweight," Knighton-Slatter said. "My dad was diagnosed with cancer and was told he has 'x' amount of time to live. To handle it, I started walking."
Knighton-Slatter temporarily moved to Florida and started riding a bicycle.
"I met with a whole group of people, and I entered a bunch of bike races," she said.
In 2001, Knighton-Slatter entered her first half-marathon.
"After I finished it, I told my husband, 'Never let me do that again,' " Knighton-Slatter said.
Despite her decree, the seeds had been planted. Knighton-Slatter was hooked on competition. She continued training.
In 2002, at age 42, Knighton-Slatter finished the Great Floridian, her first Ironman-distance event, in 16.5 hours.
"It went well," Knighton-Slatter said. "And I finished it."
There was no turning back.
"For me, it's the challenge," said Knighton-Slatter, who manages RCI Donor Services, a tissue recovery agency for organ donations. "I enjoy the physical fitness that it brings me. It makes me feel good, and I love the people I meet."
One of Knighton-Slatter's favorite people is training partner Kitty Cole of Janesville.
"We ran Door County, and we ran what I thought was the hardest triathlon in Branson, Mo.," Knighton-Slatter said. "I've trained with her for five years."
Cole has completed marathons on all seven continents, but she is 0-for-3 in finishing the Ironman Wisconsin. Knighton-Slatter is determined to get Cole to the finish line in Florida.
"We trained together and became good friends," Cole said. "She said she'd like to share her big day in Florida with me. She is my biggest cheerleader."
Knighton-Slatter makes it clear: Cole is going to finish.
"That girl is going to finish it this year," Knighton-Slatter said. "I've been there for her. Her running is strong, but her weakness is the bike. If she can get off the bike, I know she can rock the run."
Cole said it's all good with Knighton-Slatter.
"We have a healthy competition," Cole said. "I run faster, but she swims and bikes."
Besides giving and receiving inspiration from Cole, Knighton-Slatter has family and friends traveling with her, including her son, Janesville Parker graduate Enio Perez.
"It will be (Perez's) first Ironman and a growing and learning experience for him," Knighton-Slatter said.
Janesville's Charlie Meyer is also entered in Saturday's Ironman.
Once Knighton-Slatter weighed 250 pounds. She has pared down to 170. She admits she is not an elite triathlete but an average athlete who has become a stronger person through competition.
"I'm the everyday person that works a full-time job, manages a household with a husband, two boys and a poodle," Knighton-Slatter said. "Triathlon is a way of life for me.
"I love the required discipline, the hard work and the challenge."