Race-day gut issues followed Marie Stevenson through 8 years of triathlon, and she’s a family doctor. So how did she race the IRONMAN 70.3 World Championship in Nice without them?

Marie is a family doctor from Calgary, Canada, who has been racing triathlon for 17 years. She thought her nutrition was great, yet for 8 of those years she planned every run around where the portaloos were. She shares what she used to eat on race day, the everyday fuelling gap she had no idea she was carrying and the 3 changes she credits for her first race without gut issues in 8 years. She also explains how she rebuilt her carb load in a foreign country when the bag holding her race food was stuck in Amsterdam during race week.

WHAT YOU’LL LEARN
What Marie ate on race day for years, and why it kept letting her down
What 8 years of trial and error did and didn’t fix
The daily fuelling gap hiding behind a diet she believed was great
How she rebuilt her carb load when her race bag went missing before 70.3 Worlds
The 3 changes she credits for racing Nice with no gut issues
Why it’s never too late for a masters athlete to change how they fuel

TIMESTAMPS:

01:22 From marathon runner to reluctant triathlete

06:14 Her race nutrition before TNA

07:30 8 years of race-day gut issues

10:54 Why a doctor finally fixed her fuelling

12:31 The daily fuelling gap she missed

16:03 Carb loading properly for the first time

18:25 Fuelling a 1,500km cycling trip

20:57 Race week chaos at 70.3 Worlds

29:51 What fixed her gut in Nice

32:34 Better sleep and changes for her patients

34:59 Advice for masters triathletes

ABOUT MARIE

Dr Marie Stevenson is a family doctor from Calgary, Canada, and a Triathlon Nutrition Academy athlete. She took up running at 47, has run 30 marathons and qualified for the Boston Marathon along the way. She has been racing triathlon for 17 years and finished 12th in the 65 to 69 age group at the 2026 IRONMAN 70.3 World Championship in Nice, France.

RESOURCES MENTIONED
Ep 259: How 5 Masters Triathletes Fuelled the Hilliest 70.3 in the World

FUELLING THAT HOLDS UP WHEN RACE WEEK FALLS APART

Marie’s fuelling held up in Nice because she understood why her plan worked, which meant she could rebuild it on the fly. That’s what I teach inside the Triathlon Nutrition Academy, my education program where you learn how to fuel properly for training, racing and the rest of your life. Register your interest for the next cohort

SUPPORT THE PODCAST HERE

CONNECT WITH TARYN

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The Triathlon Nutrition Academy® is a podcast by Dietitian Approved®. All rights reserved.

Race-day gut issues followed Marie Stevenson through 8 years of triathlon, and she&rsquo;s a family doctor. So how did she race the IRONMAN 70.3 World Championship in Nice without them?
Marie is a family doctor from Calgary, Canada, who has been racing triathlon for 17 years. She thought her nutrition was great, yet for 8 of those years she planned every run around where the portaloos were. She shares what she used to eat on race day, the everyday fuelling gap she had no idea she was carrying and the 3 changes she credits for her first race without gut issues in 8 years. She also explains how she rebuilt her carb load in a foreign country when the bag holding her race food was stuck in Amsterdam during race week.
WHAT YOU&rsquo;LL LEARN
<ul>
<li aria-level="1">What Marie ate on race day for years, and why it kept letting her down</li>
<li aria-level="1">What 8 years of trial and error did and didn&rsquo;t fix</li>
<li aria-level="1">The daily fuelling gap hiding behind a diet she believed was great</li>
<li aria-level="1">How she rebuilt her carb load when her race bag went missing before 70.3 Worlds</li>
<li aria-level="1">The 3 changes she credits for racing Nice with no gut issues</li>
<li aria-level="1">Why it&rsquo;s never too late for a masters athlete to change how they fuel</li>
</ul>
TIMESTAMPS:
01:22 From marathon runner to reluctant triathlete
06:14 Her race nutrition before TNA
07:30 8 years of race-day gut issues
10:54 Why a doctor finally fixed her fuelling
12:31 The daily fuelling gap she missed
16:03 Carb loading properly for the first time
18:25 Fuelling a 1,500km cycling trip
20:57 Race week chaos at 70.3 Worlds
29:51 What fixed her gut in Nice
32:34 Better sleep and changes for her patients
34:59 Advice for masters triathletes
ABOUT MARIE
Dr Marie Stevenson is a family doctor from Calgary, Canada, and a Triathlon Nutrition Academy athlete. She took up running at 47, has run 30 marathons and qualified for the Boston Marathon along the way. She has been racing triathlon for 17 years and finished 12th in the 65 to 69 age group at the 2026 IRONMAN 70.3 World Championship in Nice, France.
RESOURCES MENTIONED
<ul>
<li aria-level="1"><a href="https://www.dietitianapproved.com/podcast/episode-259">Ep 259: How 5 Masters Triathletes Fuelled the Hilliest 70.3 in the World</a></li>
</ul>
FUELLING THAT HOLDS UP WHEN RACE WEEK FALLS APART
Marie&rsquo;s fuelling held up in Nice because she understood why her plan worked, which meant she could rebuild it on the fly. That&rsquo;s what I teach inside the Triathlon Nutrition Academy, my education program where you learn how to fuel properly for training, racing and the rest of your life. <a href="https://www.dietitianapproved.com/academy">Register your interest for the next cohort</a>
SUPPORT THE PODCAST <a href="https://www.dietitianapproved.com/legend">HERE</a>
CONNECT WITH TARYN
<a href="https://www.dietitianapproved.com">Website</a> | <a href="https://www.instagram.com/dietitian.approved/">Instagram</a> | <a href="https://www.facebook.com/DietitianApproved">Facebook</a> | <a href="https://www.youtube.com/@dietitianapproved">YouTube</a>
The Triathlon Nutrition Academy&reg; is a podcast by Dietitian Approved&reg;. All rights reserved.

Welcome to the Triathlon Nutrition Academy Podcast! Brought to you by Advanced Sports Dietitian, Taryn Richardson. Listen as I break down the latest science to give you practical, easy to digest strategies to transform yourself into a Supercharged Triathlete! You have so much untapped potential...and I want to help you unlock that with the power of nutrition.