How a 43-Year-Old Dad Lost 60 Pounds and Became a Triathlete
From losing 60 pounds to training for a Half Ironman, 43-year-old David Cantrell hasn't met a challenge he didn't take on headfirst. Between working long hours in private practice as an attorney and growing his family, his fitness and diet fell by the wayside. But his entire focus changed after a major health wake-up call forced him to reevaluate the direction he was heading.
"The turning point was when I was diagnosed with high cholesterol and high blood pressure, and started taking medication to manage those," Cantrell said. "I had gained about 10 pounds per year for three years in a row, and I was concerned my physical health was headed in a bad direction."
Once he committed to a complete lifestyle change, the results followed. Over the course of 14 months, Cantrell dropped from 230 pounds to 170 pounds. What started as a mission to improve his health eventually evolved into a passion for racing and pushing his own limits.
Dietary Changes
When it comes to losing weight, there's no way around a consistent and intentional diet, which is exactly what Cantrell says was the biggest factor along his journey. Off the bat, he dropped 25 pounds fairly quickly, but after that initial progress, his weight loss stalled, and he found himself struggling to move the scale any further.
That's when he recruited help from Virta Health and started following a keto diet. Using Virta's tools, he tracked both his ketone and glucose levels to better understand how his body was responding to food and exercise. He even structured workouts around those readings. For instance, when ketone levels were elevated, he knew his body was more likely to burn stored fat instead of carbohydrates, so he'd engage in high-intensity training sessions. Over the next six to eight months, he lost an additional 35 pounds.
"I meal prepped every week, mostly preparing grilled chicken breasts, turkey burgers, and boiled eggs," he said. "I ate those for dinner with a green vegetable for months and didn't get tired of the food or the diet because it was working so well."
Workout Routine
As with many people on a fitness journey, Cantrell's has been anything but one-dimensional. At first, he focused heavily on strength training, lifting four to five days a week while sprinkling in short runs whenever he could. At the time, even brief runs felt difficult because he was so out of shape, but his endurance improved, and running became a regular part of his routine. Soon, he was running every other day while still doing strength workouts afterward.
"In March 2025, I decided to sign up for a triathlon, so I incorporated swimming into my workout routine a few days a week," he shared. "I also borrowed a road bike from a friend and would ride with him on the weekends, and ride the Peloton at the gym a few days a week as well."
Cantrell had officially caught the training bug, and by May 2025, he completed his first triathlon-a 19-mile sprint. After that race, his workouts evolved significantly. Cantrell started biking around 60 miles per week on his trainer, swimming 4,000 yards per week, and running about 10 to 12 miles while strength training two to three times a week.
Later that year, he completed a 33-mile Olympic triathlon before deciding he wanted to complete a 70.3-mile half Ironman. Today, his workouts have the same bones, with higher distances across the board.
Training for a Half Ironman
Cantrell says law school played a major role in shaping the mindset that fueled his weight loss transformation. The experience made him intensely goal-oriented and showed him he was capable of far more than he originally believed. As the weight started coming off and he continued hitting milestones, that sense of accomplishment became addictive.
"I had never done any sort of race before, but signed up for my first race in March 2025, which was a 5k," he shared. "I had never run three miles at once before in my life until two weeks before the race. I felt a different level of motivation than I had felt before leading up to that race that allowed me to push myself further and harder than I'd been able to before."
After the 5K, he immediately signed up for a sprint triathlon, then an Olympic triathlon and a half-marathon, chasing that same feeling each time. Things escalated once again after he attended a full Ironman race to support a friend. Watching athletes compete in that environment lit another fire under him. Inspired by the energetic atmosphere, he couldn't wait for registration to open for the Chattanooga 70.3 Half Ironman.
"I registered for the Chattanooga race the day it opened," Cantrell added. "I'm also registered for the Omaha 70.3 half Ironman next month and the Florida 70.3 half Ironman in December. The motivation is still there and feels as good as it did the first time I experienced it over a year ago. I'm grateful to be 40 years old and have a healthy, strong body and mind that allows me to pursue these goals."
Related: This Weight Loss Hack Helped People Lose 6 Percent Body Fat
This story was originally published by Men's Journal on May 26, 2026, where it first appeared in the Health & Fitness section. Add Men's Journal as a Preferred Source by clicking here.
2026 The Arena Group Holdings, Inc. All rights reserved.
This story was originally published May 26, 2026 at 12:54 PM.