Continuous glucose monitoring and long-distance running


“As a coach, I also need to train myself to form better habits,” says Rebeka Stowe, a NYC-based athlete and running coach. “Having a real-time flow of objective metabolic data helps validate whether what I’m doing is positive or negative. Nutrition for performance has been an extensive experiment: I’ve built a much better understanding of my recovery and optimal food choices that are best suited for my body.”

Rebeka Stowe is an athlete with accolades that run the gamut: Big 12 Champion, Woman of Distinction, Olympic Trials Finalist, 7-time US Outdoor Championship Qualifier, 3-time All-American, and 3-time All-American school record holder. Today, she finds herself training for the 2021 Olympic Trials and coaching runners of all backgrounds individually, through Team Fortitude, and as a coach with NIKE Running.

“I primarily wanted to learn how my glucose levels impacted different training sessions and vice versa,” says Rebeka. “I loved the idea of having an internal view of what is actually happening in my body, and how to optimally fuel before and after my sessions without putting my metabolic system through any unnecessary strain.”

As an athlete and coach, gaining first-hand insight into her personal nutrition and recovery has been a clarifying experience, both for herself and for her athletes.

“Levels gives me concrete evidence of whether I’m making optimal choices, and the fact that I can move closer to my goals without starving or undergoing unnecessary strain is ideal,” says Rebeka. “Many runners would be shocked at what’s going on in their body. Running should be a vehicle to become the most holistically well version of yourself–not an excuse to eat poorly and put your metabolic system under undue strain.”

Rebeka has a methodical and philosophical approach to running that any athlete or performance-oriented individual can gain from.

Metabolic Data and Behavioral Change for Optimal Performance

In her pursuit to better understand how her nutrition impacted her performance, Rebeka also discovered that stabilizing her glucose levels could have a profound impact on her daily mood.

“A primary life goal of mine is showing up every day at the highest capacity possible for the people around me,” says Rebeka. “I’ve experienced sharp fluctuations in my mood and those moments have affected the relationships I have. When you get ‘hangry,’ you may end up lashing out at someone or carrying yourself in a way that you otherwise wouldn’t have.”

In order to show up at her best, Rebeka believes, one needs to own both their emotional and physical experiences and push for improvement on all fronts– and that starts with metabolic awareness and equipping oneself with the ability to navigate their emotional experience, which Rebeka distinguishes as separate from the physical experience.

 High-quality data should precede and coincide with any significant behavioral change, and that’s what Levels has provided me,” says Rebeka. “I’ve built a stronger understanding of how glucose levels impact my mood, which is very helpful to avoid irregularities.” 

Being able to see how her blood sugar influences her emotional state in real-time has been a rewarding experience for Rebeka, and these insights have transcended into her training. 

Glucose Levels and Training Psychology

There’s a heavy emotional coil that often comes with pushing your body for optimal performance as a career. Rebeka runs an average of 70 miles a week, but her BMI has frustratingly stayed relatively stagnant despite her efforts. Performance goals, particularly those tied to BMI or body image, can be incredibly demoralizing– especially when one is doing seemingly everything in their power to achieve them.

“There’s a sense of deep frustration to work extremely hard and do everything you think is right only to miss it– especially when you’re training at a high athletic level,” says Rebeka. “BMI is my target focus because it’s something I’ve always personally struggled with. In the past month of using Levels and focusing on my metabolic health, I’ve dropped 1% in my BMI, which is huge for me. For someone who runs as much as I do and still has a tough time dropping weight, finally seeing a decrease in BMI is very encouraging.”

By focusing on her metabolic data, Rebeka found small tweaks she could make in her nutrition routine that yielded favorable results on the scale.

“I recognized some of my choices actually weren’t supporting this goal. Knowing what type of food my body prefers to store as fat rather than burn as immediate fuel, I can better teach my body to lean out,” says Rebeka.

The psychological component of running is a penultimate point of focus for the world’s ambitious, and as a coach and athlete, Rebeka has come to know it well. 

“If you have a bad session, or when you feel terrible or too tired, it’s easy to believe that you’re not getting better,” says Rebeka. “It’s very easy and super common for athletes to fall into negative psychological spirals. What starts with a bad session can end up in a deep dark unmotivated place. If you were able to catch that on the front end with some objective data and understand what’s happening internally, you could severely improve the mental burden that comes with pushing your body to perform its best. “

By building metabolic awareness, Rebeka posits, runners may be able to mitigate some of the mental strain that accompanies running. 

“If you can correlate an athlete’s blood sugar in a 48 to 72 hour window of training, you may be able to tie positive or negative subjective feelings to an objective number and work on improving something tangible, like meals, timing, or pairings. I look forward to a day where I can sit down with my athletes as a coach and look at their metabolic data together and troubleshoot runs.”

Being able to take the emotion out of training by looking at raw data and science, Rebeka notes, she’s better able to mitigate the super intense highs and lows around running professionally.

“I missed the 2016 Olympic trials by one spot; I was 31st on a list of 30 people,” says Rebeka. “My goal was to go back and compete in 2020, so now I’m training for the trials in 2021. It’s been great to have another year’s worth of time to deepen my knowledge of myself and incorporate my metabolic health learnings into my training routine. If I’m on the starting line in the summer of next year, metabolic health will have played a very impactful role in getting me there.”

Rebeka’s Metabolic Health Learnings

Rebeka seems to relish the opportunity to make such significant impacts on her BMI and training routine with simple acts such as portion control and pairings.

“My metabolic improvements were basically the result of small tweaks,” says Rebeka. “For example, just a half cup of oats may work better for one specific type of training session versus ¾ of a cup. I can test where my personal line is for energy consumption by playing with serving sizes. It’s just so helpful to have an objective viewpoint rather than guessing and hoping I was doing the right thing.”

By testing the nuances of her nutrition, Rebeka has been able to improve her metabolic health and training playbooks.

“Recognizing the impact the timing of your calorie and carbohydrate intake can have on your training is a major advantage,” says Rebeka. “I found that consuming the majority of my carbohydrates later in the day is optimal for me because I do my training sessions in the morning. If I eat a more carbohydrate-dense meal at the end of the day, I tend to have much higher quality training sessions in the morning.”

“Experimenting to find the optimal pre-training meal for me is a work in progress, but having that tangible feedback is very helpful.”

“I found food pairings have a significant impact on the release of the energy from carbohydrates,” says Rebeka. “I can prime my metabolic system to utilize carbs over a more gradual period instead of an intense spike by having a meal with more protein and fat earlier than my carbohydrate-dense meals.”

“Many nutritionally-minded people measure their meals to the gram on a scale, but that’s only useful to the extent that you understand what’s happening internally,” implores Rebeka. “Different portions and types of food can impact one person drastically different than another, so you can’t assume every nutritional guide online is even a remotely perfect blueprint for your individual body.”

Today, Rebeka is incorporating training her metabolism alongside her running routines.

“I’ve been able to go out and train my body to be a little bit more metabolically flexible and use fat for less strenuous sessions,” says Rebeka. “Experimenting to find the optimal pre-training meal for me is a work in progress, but having that tangible feedback is very helpful. I’ve been fueling all of my morning aerobic recovery runs with an adaptogen mushroom coffee from a friend’s company called the Human Nutrition Project. It’s got some mushrooms, adaptogens, and some healthy fats, and I’ve had zero issues with spikes or anything in my blood sugar.”

The Psychology of Running

Rebeka works with athletes that come from a wide variety of body types, aspirations, and motivations, and she approaches her training from a single point of mental clarification and refinement.

“Running is a vehicle to become the best version of yourself, which is a balance between physical, mental, and emotional wellness,” says Rebeka. “Being holistically aligned starts with refining your values, and using your actions as a lever to prove what you believe really matters to you.”

In practice, Rebeka urges her athletes to dig deep and understand the full trajectory of their goals.

“Let’s say someone wants me to coach them to hit their goal of running a marathon under three hours,” explains Rebeka. “Before we get granular on a daily basis, we need to explore why someone really wants to do this? What else beyond running makes someone happy? What’s going to keep you disciplined and motivated in your journey if the initial spark of urgency fades? We can’t ignore the other facets of a happy life. You still have work, you have friends, you have all the other things. You’re not shutting the world out for the next year to run.”

Setting an ambitious goal, running or not, requires honoring the other aspects of your life that make you full, seeking out the harmony, and pruning the distractions.

“I like to use the metaphor of shooting an arrow with a thin, fish-line string attached to the back of it,” illustrates Rebeka. “To shoot this arrow effectively, you need to have a clear trajectory of where it’s going– you need to make sure that string isn’t going to get snagged up on something. Similarly, you must understand the trajectory of your goal: what are your values, what people in your life can help you, what tools and equipment can you leverage to have the best possible experience? All of this needs to be accounted for so you’re not just aimlessly sending arrows into the wind. Only once your values and essential considerations are aligned with your path to your goal can you fire away.”

Metabolic health and nutritional wellness, Rebeka suggests, is a crucial component of refining that trajectory. As many avid runners can attest, running goals tend to be great for aligning a life of habitual self-improvement.

“If you value running for three-hours, you probably also value your sleep, recovery, and nutrition, says Rebeka. “You are responsible for the collective minute decisions you make. If you have a decision between X meal or Y meal, and X meal is proven to take you closer to my goal, you should make the intentional decision to vote for that goal. A short feedback loop is critical to validate whether what you’re doing is actually helping.”

“Everyone’s human, and we’re always going to have moments where we don’t always choose the most optimal option,” says Rebeka. “Being cognizant of those things helps us be more aware of what we value, which ties everything together in the goal of being happy, wholehearted, content beings.”

Final Thoughts

Running and goal setting all come down to behavioral modification, and one must constantly  audit themselves to ensure their actions align with their values, and that they’re making full utilization of the tools at their disposal to successfully accomplish their goals.

“The running community stands to benefit from metabolic health because there’s a lot of misinformation,” says Rebeka. “Many people follow the calories-in, calories-out to a fault: ‘I just ran eight miles, I can have three donuts after my session, I’m fueling my body for performance!’ Which, don’t get me wrong, ice cream is one of my favorite foods, but when we’re talking optimization, we must consider the types of foods, quantities, and timing with a bit more precision.”

However, although Rebeka acknowledges the benefits of metabolic awareness for the athletic community, she views it as just the tip of the iceberg.

“I’m excited for Levels to become more readily available for the running community so I have the opportunity to share this with the athletes I work with, but metabolic health is so much more than just performance,” says Rebeka. “My grandmother passed away from diabetes, and I have a history of diabetes in my family, so metabolic dysfunction hits home. There are 90 million people in our country that are prediabetic or have symptoms of prediabetes and don’t even know it.”

Rebeka paints a picture of millions of people plagued by things like irregular moods and poor health that are also negatively impacting their personal lives, and how building a stronger metabolic foundation could potentially alleviate things.

“Making metabolic awareness a priority for just a few months can have a profound impact on your day-to-day life, whether you’re a high-level athlete or not,” asserts Rebeka. “Shaping your wellness education with objective data can also have generational implications. If we can make strides for better metabolic health, we’ll likely also carry those benefits to future generations.”