Widely considered one of the toughest foot races on the planet, the Marathon des Sables (MDS) is a six-stage ultramarathon covering more than 150 miles over seven days. As if that’s not grueling enough, the challenge is elevated by the extreme conditions of the Moroccan Sahara, where desert temperatures regularly exceed 100 degrees and shifting sand dunes test the mind as much as the body. Yet more, competitors must be wholly self-sufficient, carrying all of their food, clothing, sleeping and survival gear with them.

Magdalena Boulet, who captured the MDS crown in 2018, calls the event “unforgiving.”

So, as Boulet prepared for her second MDS run last April, a return trip prompted by an invite from former U.S. Olympian Des Linden, she leaned heavily into her previous MDS experience as well as her position as president of GU Energy Labs to fuel her performance.

“I felt like I could play a role in someone else’s experience and that really drew me back to MDS,” Boulet says.

Preparing with a purpose

Boulet first joined GU in 2000 for a seven-year stint that included serving as director of research and development. She then pursued other endeavors, such as coaching at her alma mater, the University of California, Berkley, launching the Bay Area Track Club and continuing her own athletic pursuits, including earning a spot on the 2008 U.S. Olympic Team in the women’s marathon.

In 2013, Boulet returned to GU as the nutrition company’s vice president of innovation, research and development before moving into the president’s role in November 2021. Over the last five years, Boulet has strengthened the brand’s relationship with premier events such as the Western States 100-Mile Endurance Run (WSER), spearheaded land stewardship initiatives, including joining 1% for the Planet, and supported the development of new products, such as the two new flavors of Liquid Energy (Plain & Simple and Passion Fruit Orange Guava) GU released in late June.

All this to say Boulet knows – and believes in – GU’s capabilities, especially those of its GU Performance Lab helmed by Dr. Roxanne Vogel.

Boulet describes the lab as a place where GU gets to “unlock human potential.” The lab performs physiological testing designed to prepare athletes for whatever adventures they’re chasing. It pairs the study of human physiology with environmental conditions, such as altitude, heat and cold, and then leverages that information to build a nutrition plan for the athlete to inform both training and racing.

“To show up at the starting line as prepared as possible,” says Boulet, a former WSER and Leadville Trail 100 champion.

As Boulet prepped for MDS, she leaned on Vogel and the GU Performance Lab to help her maximize her fueling program. For instance, Boulet ventured to southern California beaches and logged miles in the sand while overdressed to mimic MDS race conditions. Vogel, meanwhile, gathered information on key metrics like sweat rate and caloric expenditure.

“We did a couple of tests to make sure I was only bringing in enough nutrition for what I needed and not extra,” Boulet says.

The supercharged work the GU Performance Lab engages in with Boulet and others benefits the athletes, of course, but also uplifts the company, which uses the testing to drive its innovation engine and develop products for the masses.

“Extreme events are a great playground for us to learn from, to test and personalize the protocols that can help us perform at our best,” Boulet says, adding that GU exists to serve athletes. “More people deserve to feel better.”

Applying lessons to everyday athletes

Boulet’s work with Vogel helped her design her MDS nutritional plan, which included creating “meals” alongside Vogel in the kitchen.

“We put every single calorie together in our little Ziploc bags, so all I needed to do was add water to hydrate my food,” Boulet says, reminding that she needed to pack as light as possible given the MDS’s “self-sufficient” requirements.

For her “moving fuel,” Boulet relied on GU’s performance Roctane products like Roctane Energy Drink, which feature electrolytes, carbs and amino acids. In addition, she used prototype products designed to manage heat, such as a Roctane Cooling Menthol Gel GU has been testing with athletes to reduce thermal discomfort.

“That was kind of a shot of, ‘I’m awake. I’m ready to go. I’m ready to take this on,’” Boulet says of the still-in-development product based on Vogel’s PhD research.

The preparation and assistance from the GU Performance Lab helped Boulet complete the punishing, 168-mile MDS event in 37:31:22.

While Boulet certainly benefited from access to Vogel and the lab, she says the average Joes and Janes of the world can learn more about their physiology and build thoughtful nutritional plans to fuel their own adventures as well. Physiology labs are now scattered around the country, which has democratized access to understanding one’s own body.

In addition, credible research has never been more available to deliver sensible, evidence-backed recommendations. People can start with general guidelines, Boulet says, and then personalize their nutrition through experimentation and testing. Run specialty shops, meanwhile, can help disseminate trustworthy information and be a community nexus providing heightened awareness and understanding as well as product education.

“Part of the impact that GU wants to have on the athletic community is to share that research, to talk about some of these experiences and how you can adapt some of the learnings to your personal challenge and nutritional plan,” Boulet says, adding that there are many lessons GU and others can peel back from an extreme event like MDS and then bring to the masses. “That is where we want to lean in and really serve athletes.”