For many runners, crossing the finish line of their first 100-miler is a life-changing experience. For Osmo Ambassador Mark Marzen, his first finish was more than just difficult—it was torturous.
Twelve years ago, Mark set out to complete his first 100-mile race, pushing his body and mind to the absolute limit. With 20 miles to go, his body shut down, forcing him to crawl to the finish in 31 hours and 39 minutes. The moment he crossed the line, he swore he’d never attempt another 100-miler. But, as time passed, that struggle became a turning point. He discovered a deep passion for running, coaching, and most importantly, the process of continuous improvement. And so, he set an ambitious goal:
Could he run a 100-miler in half the time of his first?
A few weeks ago after over a decade of dedication, Mark accomplished his dream. He completed the Jackpot 100 in 15 hours and 37 minutes, proving that with consistent training, smart fueling, and hydration dialed in, the impossible becomes possible.
The Training: 100+ Mile Weeks Fueled by Osmo
Mark’s journey to cutting his time in half didn’t happen overnight. It took years of methodical training, during which he refined his approach to running, recovery, and most importantly, fueling his body for optimal performance.
Leading up to Jackpot 100, Mark logged 100+ mile training weeks, incorporating Osmo Fuel and Hydration daily. These products became essential in sustaining his energy, preventing bonks, and ensuring proper recovery. After every run, he relied on Osmo Recovery—keeping it readily available in his kitchen and car to jumpstart muscle repair and minimize fatigue after long sessions.
When training for a 100-mile race, long training runs are essential. Mark regularly tackled runs over 30 miles, and on those days, he didn’t just take one serving of Osmo Recovery—he took multiple throughout the day to replenish his body and prepare for the next challenge.
Race Day Strategy: Hydration and Nutrition on Lock
Mark knew that hydration and nutrition would be the key to maintaining a consistent pace and minimizing the gradual slow-down that happens in ultra races. He developed a strategic fueling plan to keep his energy levels stable throughout the 100-mile effort:
✔️ 80-100g of carbohydrates per hour
✔️ 600-800mg of sodium per liter, adjusting based on temperature
✔️ 900g of carbs from Osmo products, with zero GI distress
Given that the Jackpot 100 was run on a 1.19-mile loop course, Mark had a unique advantage—seeing his crew every 10 minutes. This setup allowed him to fine-tune his hydration and fueling throughout the race.
The Role of Osmo Fuel
Mark relied on Osmo Fuel for the majority of his carb intake, ensuring he had steady energy without GI issues. He began the race with regular Osmo Fuel and then, at mile 60, switched to Osmo Fuel with Caffeine—which provided the extra boost he needed to stay strong for the final 40 miles.
With 400mg of sodium per serving, Osmo Fuel played a critical role in maintaining electrolyte balance, preventing dehydration, and keeping his muscles firing efficiently.
Adjusting for the Heat
In the heat of the afternoon, when temperatures climbed into the 60s, Mark adjusted by incorporating extra water and additional servings of Osmo Hydration to stay ahead of dehydration. The ability to customize his intake based on conditions was key to maintaining a steady effort from start to finish.
The Results: A PR and a Breakthrough
Mark’s meticulous approach to training, nutrition, and hydration paid off in a massive personal best. He cut his 100-mile time in half, finishing in 15 hours and 37 minutes—a feat that once seemed like a dream.
Perhaps the most remarkable part?
“Ever since I started using Osmo in ultramarathons, I have yet to bonk or have GI issues—all while gradually increasing my carbohydrate intake rate.”
For ultra runners, avoiding bonking and digestive distress is often the hardest part of race execution. By dialing in his hydration and fueling with Osmo, Mark has not only improved his performance, but he’s also eliminated common ultra-running pitfalls that derail so many athletes.
The Takeaway: Fuel Smart, Train Smart, and Reimagine Your Limits
Mark’s journey is an inspiration to runners everywhere. His experience proves that when you trust the process, fuel properly, and stay persistent, you can redefine what’s possible.
Hydration and nutrition aren’t just side elements of training—they’re cornerstones of performance. Whether you're tackling your first ultra or chasing a new PR, Osmo can help you optimize your hydration, fueling, and recovery.
