Protein vs. “Super Carbing”: Are Endurance Athletes Fueling the Right Way?
If you spend any time in endurance sports right now, you’ve probably noticed a major shift in fueling advice.
For years, endurance athletes were told to eat plenty of carbohydrates. Now, the message has evolved into something more extreme: “super fueling.” Athletes are encouraged to consume 90–120 grams of carbohydrate per hour during training and racing.
At the same time, another conversation is happening, one that focuses less on maximizing carb intake and more on improving metabolic health and prioritizing protein.
In a recent episode of the Maximum Mileage Running Podcast, Coach Faye Johnson and I spoke with sports dietitian Bob Seebohar, founder of eNRG Performance, about this growing divide in endurance nutrition.
Bob has spent decades working with endurance athletes, Olympic programs, and national governing bodies. His work focuses on improving metabolic health, reducing gastrointestinal distress, and helping athletes fuel in ways that support both performance and long-term health.
The takeaway from our conversation? The real answer isn’t as simple as “more carbs” or “low carb.” Instead, it starts with health, metabolic flexibility, and a strong daily nutrition foundation.
Let’s unpack the debate.
The Rise of Super Carbing
The current fueling trend in endurance sports emphasizes very high carbohydrate intake during training and racing.
Elite athletes are often encouraged to consume:
- 90–120 grams of carbohydrate per hour
- Multiple sugar sources such as glucose and fructose
- Frequent fueling every 15–20 minutes
This approach can absolutely benefit athletes performing at very high intensities, particularly at the elite level where maximizing carbohydrate oxidation can support peak performance.
However, there is a catch. This strategy is often applied broadly to recreational endurance athletes training at much lower intensities.
That is where problems can start.
Many runners and endurance athletes experience gastrointestinal distress, including bloating, nausea, cramping, or vomiting when attempting these fueling strategies.
According to Bob Seebohar, this isn’t surprising.
“GI distress has almost become normalized in endurance sports,” he explained on the podcast. “But it shouldn’t be.”
Why Gut Issues Are So Common
Endurance training places significant stress on the digestive system.
During exercise:
- Blood flow shifts away from the gut
- Mechanical impact disrupts digestion
- Stress hormones increase
- Large quantities of simple sugars are introduced
If the digestive system isn’t healthy to begin with, or if fueling strategies are mismatched to the athlete’s metabolic needs, this combination can quickly lead to problems.
Rather than treating symptoms on race day, Bob recommends a proactive approach that begins months before competition.
His strategy starts with improving gut health, reducing stress on the system, and building a strong daily nutrition foundation.
The Missing Piece: Protein
One of the most common nutrition gaps Bob sees in endurance athletes is surprisingly simple.
Not enough protein.
Protein plays critical roles in:
- Hormone production
- Muscle repair
- Immune function
- Blood sugar regulation
- Satiety and metabolic health
Yet many endurance athletes structure their diets almost entirely around carbohydrates.
Bob’s recommended eating order is straightforward:
- Protein first
- Fruits and vegetables
- Whole-grain carbohydrates if additional energy is needed
This sequence helps regulate blood sugar and insulin while ensuring the body gets the nutrients it needs for long-term health.
For many athletes, simply correcting this imbalance dramatically improves energy levels, recovery, and overall well-being.
Metabolic Efficiency: Burning More Fat
Bob’s approach centers around a concept called Metabolic Efficiency Training (MET).
The goal is to teach the body to:
- Burn more fat for energy
- Preserve limited carbohydrate stores
- Maintain stable blood sugar levels
This is achieved through a combination of:
- Daily nutrition strategies
- Lower-intensity aerobic training
- Periodized carbohydrate intake
The result is that athletes who become metabolically efficient often require less carbohydrate during exercise, sometimes as little as 10–60 grams per hour, depending on intensity and duration.
This stands in contrast to the current trend that suggests more carbohydrate intake is always better.
Health Before Performance
Perhaps the most important point from our conversation with Bob is this:
Performance should never come at the expense of health.
Before experimenting with fueling strategies, Bob strongly encourages athletes to understand what is happening inside their bodies.
That means looking at biomarkers such as:
- Blood lipids
- Blood sugar regulation
- Hormonal health
- Inflammation markers
Feeling good during a workout does not always mean the body is functioning optimally.
As Bob put it during the podcast, sometimes we need to “pop the hood” and see what is really going on internally.”
So Which Approach Is Right?
The truth is that endurance nutrition is not one-size-fits-all.
High-carbohydrate fueling strategies may work well for:
- Elite athletes racing at extremely high intensities
- Events where carbohydrate oxidation is maximized
However, many recreational endurance athletes may benefit from:
- Improving metabolic efficiency
- Prioritizing protein intake
- Supporting gut health
- Building a sustainable daily nutrition strategy
In other words, the question is not simply:
“How many carbs should I take during a run?”
A better question might be:
“How healthy and metabolically flexible is my system in the first place?”
A Simpler Framework for Endurance Nutrition
Bob shared a simple four-step framework he uses with athletes:
- Testing to understand biomarkers and metabolic function
- Daily nutrition to support health and stabilize blood sugar
- Nutrient timing for training and racing
- Supplements, only if needed after the first three steps are in place
The key idea is simple.
Health first. Performance second.
When the body is functioning well internally, performance tends to follow.
The Bottom Line
The protein versus super-carb debate is not about choosing one extreme over the other.
It is about recognizing that endurance performance depends on more than just carbohydrate intake.
Gut health, metabolic efficiency, protein intake, and overall nutrition quality all play important roles.
For many runners, the solution is not adding more gels.
It is building a healthier foundation first.
Want to Learn More About Metabolic Efficiency and Athlete Testing?
If this conversation sparked your curiosity about your own fueling strategy, working directly with a qualified professional can provide valuable insight.
Bob Seebohar, founder of eNRG Performance, works with athletes around the world to evaluate metabolic efficiency, analyze key biomarkers, and develop individualized nutrition strategies that support both health and performance. His approach begins with data, including metabolic efficiency testing and bloodwork, to create a clear picture of how an athlete’s body is functioning.
If you’re interested in learning more about testing or working with Bob, you can explore his services here:
https://www.enrgperformance.com/bob-seebohar
At Maximum Mileage Coaching, we share a similar philosophy. We believe the best endurance training comes from science-based principles and a long-term view of athlete health.
Our coaching approach focuses on helping runners build durable training habits, progress gradually, and support their running with balanced lifestyle and nutrition strategies. Rather than chasing quick fixes or extreme approaches, we help athletes develop sustainable routines that support both performance and longevity.
Whether you’re training for your first half marathon, returning to running after injury, or preparing for your next big endurance goal, our goal is to help you run stronger, stay healthy, and enjoy the process along the way. Click "Enquire Now" to learn more.
