Sep 17, 2026 · 1 hr 4 min · 13 segments
[\[Download\] Nutrition Blueprint](https://learn.sparkhealthyrunner.com/nutrition) Are you carb loading correctly before your marathon, or could your nutrition strategy be setting you up to hit the…
Brooke CzarneckiGuest[upbeat music] You've been told to eat a big pasta dinner the night before a marathon, and I'm here to tell you that might actually be what's causing you to hit the wall at mile 20.
As a running physical therapist and coach, I've worked with hundreds of runners, and one of the most common mistakes I see isn't about training at all.
It's actually about fueling, and specifically what happens when the two or three days before your actual race day.
And the truth is, most runners, even experienced ones, are getting their carb-loading strategy completely wrong, whether that's eating the wrong foods, timing it incorrectly, or just not taking nearly enough carbs to top off those glycogen stores, and then they wonder why they're struggling at mile 18, 19, 20, hitting that dreaded wall.
So today, I have a very special guest with me, Brooke Sarnacki, registered dietitian, nutritionist, endurance sports nutrition expert, and host of the Actively Fueled podcast.
She works specifically with runners, and today she's gonna break down everything you need to know about carb loading, what to eat, when to start, and the biggest mistakes she sees runners making all of the time.
You're always bringing, bringing the heat, bringing the goodness, um, and bringing the knowledge.
So kinda getting right into it, like, we hear hitting the wall at mile 20 constantly.
Like, how much of that is actually nutrition failure versus training failure? And could proper carb loading prevent this type of thing?


Um, carb loading could potentially prevent it, but we also need to look at all the other factors too, um, like how did the rest of your training cycle go? Are you trained up to actually run this marathon? How does your during-run fuel look? Are you f- well-fueled throughout your days? How have your, has your nutrition been throughout your entire training cycle? So long story short Carb loading can be very powerful, but it is not like this, you know, one size fits all and that you absolutely have to do it, and yes, it's gonna prevent that hitting the wall.

There's lots of other factors at play, of course, um, but it can definitely, definitely help prevent or delay the hitting of the wall.
So yeah, if you've only done like a 16-mile long run, and you're wondering, like, why you're hitting the wall for your marathon, then maybe, like, that is related to training.
But I think for those of you who have been following the plans, if you've been doing an 18-miler or a 20-miler, um, you've been feeling good during training, but you really just haven't put the pieces together on race day, I think this could definitely apply to you in terms of, like, the nutrition bucket, um, whether it is the carb load itself or, like you mentioned, um, possibly, like, under-fueling throughout your day and how you're feeling during your training, which kind of spills over into, um, the race itself.
And really, like, m- Brooke, most runners I work with think of, like, the carb loading just means to eat that big pasta dinner the night before their race.
[upbeat music] You've been told to eat a big pasta dinner the night before a marathon, and I'm here to tell you that might actually be what's causing you to hit the wall at mile 20.
As a running physical therapist and coach, I've worked with hundreds of runners, and one of the most common mistakes I see isn't about training at all.
It's actually about fueling, and specifically what happens when the two or three days before your actual race day.
And the truth is, most runners, even experienced ones, are getting their carb-loading strategy completely wrong, whether that's eating the wrong foods, timing it incorrectly, or just not taking nearly enough carbs to top off those glycogen stores, and then they wonder why they're struggling at mile 18, 19, 20, hitting that dreaded wall.
So today, I have a very special guest with me, Brooke Sarnacki, registered dietitian, nutritionist, endurance sports nutrition expert, and host of the Actively Fueled podcast.
She works specifically with runners, and today she's gonna break down everything you need to know about carb loading, what to eat, when to start, and the biggest mistakes she sees runners making all of the time.
You're always bringing, bringing the heat, bringing the goodness, um, and bringing the knowledge.
So kinda getting right into it, like, we hear hitting the wall at mile 20 constantly.
Like, how much of that is actually nutrition failure versus training failure? And could proper carb loading prevent this type of thing?


Um, carb loading could potentially prevent it, but we also need to look at all the other factors too, um, like how did the rest of your training cycle go? Are you trained up to actually run this marathon? How does your during-run fuel look? Are you f- well-fueled throughout your days? How have your, has your nutrition been throughout your entire training cycle? So long story short Carb loading can be very powerful, but it is not like this, you know, one size fits all and that you absolutely have to do it, and yes, it's gonna prevent that hitting the wall.

There's lots of other factors at play, of course, um, but it can definitely, definitely help prevent or delay the hitting of the wall.
So yeah, if you've only done like a 16-mile long run, and you're wondering, like, why you're hitting the wall for your marathon, then maybe, like, that is related to training.
But I think for those of you who have been following the plans, if you've been doing an 18-miler or a 20-miler, um, you've been feeling good during training, but you really just haven't put the pieces together on race day, I think this could definitely apply to you in terms of, like, the nutrition bucket, um, whether it is the carb load itself or, like you mentioned, um, possibly, like, under-fueling throughout your day and how you're feeling during your training, which kind of spills over into, um, the race itself.
And really, like, m- Brooke, most runners I work with think of, like, the carb loading just means to eat that big pasta dinner the night before their race.
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