Meet Mark. He’s an experienced runner preparing for the Tucson Marathon. He’s completed marathons before, but this time, he has a specific goal: achieve a personal record.
Mark is consistent with his training and knows the basics of running nutrition. He’s read articles about carbohydrate intake, how much protein he should eat, understands that fueling before a run is important, and has experimented with different strategies.
Despite these efforts, he continues to experience the same frustrating problem: around miles 10–12 of his longer runs, his energy starts to decline.
Some days, he feels great. Other days, he struggles to maintain his pace despite feeling physically prepared for the workout.
He’s putting in the training, but he doesn’t feel like he’s reaching his full potential.
That’s where working with a sports dietitian comes in.
Credit: Sam Siliton
Step 1:
Understanding the Runner, Not Just the Miles
During our first appointment, we’re not immediately jumping into a marathon meal plan.
Instead, we start by looking at the bigger picture.
We discuss Mark’s training schedule, running history, current eating habits, recovery, hydration, and previous fueling experiences. We explore what he’s eating throughout the day, what his nutrition looks like before and during long runs, and how he feels afterward.
One of the first things we identify is that while Mark is eating carbohydrates before his runs, he may not be consuming enough throughout the day to consistently support his training demands.
This is an important distinction. Fueling for a marathon isn’t just about what you eat the morning of your run. It’s about how you fuel throughout the day, the week, and the entire training cycle.
Together, we develop a few realistic goals to increase his carbohydrate availability and support his overall energy intake. We focus on incorporating more carbohydrate-rich foods into meals and snacks while maintaining adequate protein, healthy fats, and micronutrient intake.
Rather than overhauling everything at once, we choose changes that fit Mark’s schedule, food preferences, and lifestyle.
Step 2:
Building Consistency Before Adding Complexity
Within our next few appointments, we evaluate how those changes are going.
Mark reports that he’s feeling more energized throughout the day, and his runs have started to feel easier.
Now that he’s consistently fueling his daily training, we can turn our attention to his longer runs.
We discuss the importance of carbohydrate intake during prolonged exercise, including how much he may need based on the duration and intensity of his workouts.
We also explore practical options: does Mark prefer gels, sports drinks, applesauce, bars, chews, or a combination? What is easiest for him to carry? Which products sit comfortably in his stomach?
Together, we create an initial fueling strategy and begin practicing it during training.
This is where individualization becomes especially important.
Two runners completing the same mileage may require different approaches depending on their training intensity, gastrointestinal tolerance, food preferences, and fueling experience.
Our goal isn’t simply to give Mark a carbohydrate target. It’s to help him consistently meet that target in a way that works for him.
Credit: VAF Photos.
Step 3:
Practicing Race-Day Nutrition Before Race Day
As Mark’s training progresses, we start preparing for an upcoming half marathon that he plans to use as a trial run for his full marathon.
We develop a nutrition plan that includes his meals the day before, pre-race breakfast, hydration, carbohydrate intake during the race, and recovery nutrition afterward.
We calculate individualized fueling targets and select foods and products that he enjoys and can tolerate.
The half marathon gives us an opportunity to test his strategy in a race environment.
And it goes well.
Mark reports more consistent energy, improved confidence in his fueling strategy, and no significant gastrointestinal discomfort.
However, the process doesn’t stop there.
A half marathon is a valuable opportunity to practice, but it doesn’t completely replicate the demands of a full marathon. As Mark’s long runs increase in duration, we continue adjusting his fueling plan to match those demands.
We practice higher carbohydrate intakes when appropriate, evaluate his hydration needs, and develop a realistic plan for the days leading up to his marathon.
By the time race day approaches, Mark isn’t trying anything new. He’s following a strategy that has already been practiced, evaluated, and refined throughout his training.
Step 4:
Adjusting the Plan as Training Changes
One of the biggest benefits of ongoing nutrition coaching is that your needs don’t remain the same throughout a training cycle.
A recovery week looks different from a high-mileage week. A 45-minute easy run requires a different fueling approach than a 20-mile long run.
As Mark’s training volume increases, we adjust his nutrition to better support his energy needs, recovery, and performance.
Throughout this process, Mark notices that he’s recovering more consistently, maintaining his energy during longer workouts, and feeling more prepared for the demands of marathon training.
He also avoids the recurring aches and setbacks that had previously interrupted some of his training. While nutrition alone cannot prevent injuries, meeting energy and nutrient needs is an important part of supporting recovery and overall training health.
Perhaps most importantly, Mark becomes more confident in understanding his own fueling needs.
Rather than guessing what he should eat, he has developed the skills to make informed nutrition decisions as his training changes.
How Often Should a Marathon Runner
See a Sports Dietitian?
One of the most common questions I receive is: “How many appointments will I need?“.
The answer is that it depends.
Every runner comes into nutrition coaching with a different background, different goals, and different challenges.
Some individuals, like Mark, are able to implement nutrition changes relatively quickly. They may benefit from an initial appointment to establish a plan, followed by a few weekly follow up appointments to establish education and habit building, then appointments at key points in their training cycle to evaluate progress and adjust their strategy.
Other runners benefit from more frequent appointments.
For example, someone who struggles with eating consistently, experiences frequent gastrointestinal issues, or has difficulty implementing new habits may benefit from meeting every one to two weeks.
These appointments provide an opportunity to troubleshoot barriers, build skills, and make gradual changes without feeling overwhelmed.
As those habits become more consistent, appointments can become less frequent.
The goal of nutrition coaching isn’t to create dependency on a dietitian. It’s to give runners the knowledge, tools, and confidence to fuel themselves effectively.
For some runners, that may take a few targeted appointments initially with monthly follow ups. For others, it may involve weekly or bi-weekly coaching throughout an entire training cycle.
There’s no one-size-fits-all appointment schedule, just as there’s no one-size-fits-all marathon fueling plan.
Why Work With a Sports Dietitian When There's So Much Information Online?
There’s an incredible amount of sports nutrition information available online, and much of it can be helpful.
You can find general recommendations for carbohydrate intake, hydration, recovery, and race-day fueling with a quick search.
But knowing what the recommendations are and knowing how to apply them to your own training are two different things.
You may know that you need carbohydrates during a marathon, but how much can you comfortably tolerate? When should you start fueling? What should you eat the day before a long run? How do you adjust when your training volume changes?
And what happens when you’re following the general recommendations but still struggling with low energy?
A sports dietitian helps connect the science of nutrition to your individual circumstances.
For Mark, that meant identifying gaps in his daily fueling, developing a strategy for his longer runs, and practicing race-day nutrition well before the Tucson Marathon. It also meant making adjustments along the way instead of expecting one plan to work perfectly from the beginning.
Credit: RUN4FFWPU
The Finish Line
By the end of his training cycle, Mark’s biggest improvement wasn’t simply having a marathon fueling plan.
It was understanding how to fuel his body through every stage of training.
He learned how to adjust his intake as his mileage increased, how to recognize when his fueling wasn’t meeting his needs, and how to practice strategies that supported consistent energy and recovery.
His progress wasn’t the result of a single nutrition recommendation. It came from a series of individualized changes, practiced consistently and adjusted over time.
You spend months preparing your body to run 26.2 miles. Your nutrition deserves that same level of preparation.
Whether you’re training for your first marathon or chasing a personal record, working with a sports dietitian can help you develop a fueling strategy that supports your training, recovery, and performance.
Win Your Marathon
Jackie Hatchew, MS, RD is a registered dietitian at Smith Performance Center who helps active adults address fatigue, recovery issues, and performance plateaus by improving energy capacity. Her approach focuses on practical, individualized fueling strategies that support training, injury recovery, and daily life without restriction or rigid diets.
