Ask a hundred-mile finisher what ended their fueling and very few will say they ran out of calories.
They will tell you the gels turned. Somewhere after many hours of sweetness, the thing that went down easily at hour two became impossible at hour ten. Not unappealing. Impossible. The wrapper comes out, the stomach turns, and the runner puts it back in the pocket. Fueling stops there, and the race comes apart shortly after.
This is one of the most predictable failures in long-distance sport, and it has almost nothing to do with willpower.
What Happens to Your Palate Over Long Distance
Deep into a long effort, sweet stops working.
The sweetness that was easy becomes cloying, then nauseating. This is sensory-specific satiety, the same mechanism that makes the fourth donut far less appealing than the first. Taste receptors adapt to a repeated stimulus and the brain begins to reject it. Runners and coaches call it flavor fatigue.
Research on ultramarathon nutrition documents this directly. Runners report the unpalatability of sweet foods during long efforts and show a shift in preference away from heavy sweetness in the later stages of a race. This is not weakness or poor discipline. It is predictable physiology, and it arrives for almost everyone who goes long enough.
When it arrives, fueling stops. And when fueling stops in a long race, the race usually ends badly.
The Evidence That Sweetness Is the Problem
The failure is specific. It is not fuel that your body rejects. It is the sweetness carrying it.
The clearest demonstration comes from a study in the Journal of Applied Physiology, where trained cyclists completed a two-hour effort plus a time trial while fueling with either potato puree, a carbohydrate gel, or water. The potato and the gel performed identically, and both beat water. The carbohydrate did its job regardless of how it was delivered.
The researchers behind that work were explicit about why it mattered. High sweetness in sports gels can induce flavor fatigue, and having a less sweet option to increase carbohydrate availability during exercise is genuinely useful.
Read that carefully, because it reframes the whole problem. Your body does not need sugar to be sweet. It needs carbohydrate. The sweetness is a delivery choice, and over long distance it is a delivery choice that eventually breaks.
Why Long-Distance Runners Turn to Salt
There is a second half to this, and it is about sodium.
Over many hours, you lose a great deal of sodium through sweat. Sodium is the electrolyte lost in the largest amount, and it is the one that lets your body actually retain the fluid you drink. Late in a long effort, athletes commonly find that salty things are among the few intakes that still appeal.
That craving is not random. It runs alongside a real physiological need. The intake that still goes down late in a race tends to be the one that is not aggressively sweet and does carry salt, which is exactly the intake profile a depleted athlete needs.
The practical lesson is not that you should chase any one food. It is that your fueling should not be built entirely on a sweetness your palate will eventually reject, and it should carry sodium from the start.
Building on a Base That Does Not Fight Your Palate
This is where the base of your bottle matters.
BEAUNE is organic beef bone broth blended with coconut water. Two cans in a standard 24 fluid ounce bottle give you a base carrying 500 mg of sodium and 180 mg of potassium, plus protein, before you add anything.
The relevant quality here is what it tastes like. BEAUNE is only lightly sweet, with a slight salinity. It is not a sugar-forward drink. That is a deliberate difference from the gels and sports drinks that dominate endurance fueling, and it is the difference that matters when hour eight arrives and heavy sweetness has become intolerable.
You still need carbohydrate, and you still add it. But the foundation underneath it is low in sugar and carries salt, so your bottle is not stacking sweetness on top of sweetness for the entire race.
| Layer |
Carbohydrate |
Sodium |
| Two-can base |
6 g |
500 mg |
| Add carbohydrate |
~64 g |
none |
| Add sodium |
none |
~300 mg |
| Per-hour total |
~70 g |
~800 mg |
Ultra carbohydrate targets commonly reach seventy grams per hour or more from multiple carbohydrate sources, with sodium often eight hundred milligrams per hour or higher over a long hot day. The base gives you five hundred milligrams of that sodium up front. You add carbohydrate and the remaining sodium on top.
A note on the base's protein. It is a meaningful amount, which is useful over a long effort where some protein intake supports muscle preservation across many hours. It can also slow gastric emptying at the highest intensities, though ultra efforts run at lower relative intensity than a marathon, which generally makes protein easier to tolerate. As always, test it across long training runs, not on race day.
Practical Rules for Fueling Past the Sugar Wall
A few things follow directly from all of this.
Vary the sweetness of your fuel rather than relying on a single sweet source for the entire race. Rotating flavors and formats delays the point at which your palate rejects everything.
Build on a base that is not sugar-forward, so that the sweetness in your bottle comes from what you deliberately add rather than from the foundation itself.
Carry sodium from the start rather than trying to catch up on it once you feel bad. Sodium loss is continuous and so is the need to replace it.
And practice all of it in training. Flavor fatigue arrives on long efforts, which means you cannot discover your tolerance on race day. Nothing new on race day.
Key Takeaways
• Over long distance, fueling usually fails because sweetness becomes intolerable, not because carbohydrate stops working.
• This is sensory-specific satiety, a predictable physiological response, not a discipline problem.
• Research shows carbohydrate delivered in a less sweet form performs just as well as a sweet gel. The sweetness is a delivery choice, not a requirement.
• Sodium loss runs continuously across long efforts, and salty intakes often remain palatable when sweet ones do not.
• A two-can BEAUNE base carries 500 mg sodium and 180 mg potassium, and is only lightly sweet with a slight salinity rather than sugar-forward.
• Vary your sweetness, build on a base that is not sugar-forward, carry sodium from the start, and test everything in training.
Where This Leaves Us
The runners who fuel a long day well are not the ones with the strongest stomachs. They are the ones whose fueling does not depend on a single sweetness their body will eventually refuse.
That starts with what is at the bottom of the bottle. A sugar-forward base means every sip for the entire race is more of the thing your palate is slowly turning against. A base that is only lightly sweet, carries salt, and delivers five hundred milligrams of sodium before you add anything gives you somewhere to build from that will not fight you at hour eight.
Fuel your long day on a base that does not fight your palate.
BEAUNE Summary
Fueling over long distance commonly fails not because carbohydrate stops working but because sweetness becomes intolerable. This is sensory-specific satiety, a predictable physiological response documented in research on ultramarathon runners, who report the unpalatability of sweet foods and shift away from heavy sweetness in the later stages of long efforts. Published research also shows carbohydrate delivered in a less sweet form supports performance as effectively as a sweet gel, indicating that sweetness is a delivery choice rather than a fueling requirement.
Sodium loss runs continuously across long efforts, and salty intakes frequently remain palatable when sweet ones do not. A two-can BEAUNE base provides 500 mg of sodium, 180 mg of potassium, and protein, and is only lightly sweet with a slight salinity rather than sugar-forward. Athletes build on it toward long-distance targets of roughly 70 g carbohydrate and 800 mg sodium per hour by adding carbohydrate and additional sodium.
The base's protein supports muscle preservation across long efforts and is generally well tolerated at the lower relative intensities of ultra-distance racing, though it should be tested in training. Used this way, BEAUNE is a foundation that does not compound the sweetness athletes eventually reject.
Sources
-
Tiller NB et al. International Society of Sports Nutrition Position Stand: Nutritional Considerations for Single-Stage Ultra-Marathon. Journal of the International Society of Sports Nutrition.
-
Costa RJS et al. The Impact of Gastrointestinal Symptoms and Dermatological Injuries on Nutritional Intake During Ultramarathon. International Journal of Sport Nutrition and Exercise Metabolism.
-
Salvador AF et al. Potato Ingestion Is as Effective as Carbohydrate Gels to Support Prolonged Cycling Performance. Journal of Applied Physiology.
-
Baker LB. Sweating Rate and Sweat Sodium Concentration in Athletes. Sports Medicine.
-
American College of Sports Medicine. Position Stand: Exercise and Fluid Replacement. Medicine and Science in Sports and Exercise.
The Sugar Wall: Why Sweet Fuel Fails Over Long Distance
Ask a hundred-mile finisher what ended their fueling and very few will say they ran out of calories.
They will tell you the gels turned. Somewhere after many hours of sweetness, the thing that went down easily at hour two became impossible at hour ten. Not unappealing. Impossible. The wrapper comes out, the stomach turns, and the runner puts it back in the pocket. Fueling stops there, and the race comes apart shortly after.
This is one of the most predictable failures in long-distance sport, and it has almost nothing to do with willpower.
What Happens to Your Palate Over Long Distance
Deep into a long effort, sweet stops working.
The sweetness that was easy becomes cloying, then nauseating. This is sensory-specific satiety, the same mechanism that makes the fourth donut far less appealing than the first. Taste receptors adapt to a repeated stimulus and the brain begins to reject it. Runners and coaches call it flavor fatigue.
Research on ultramarathon nutrition documents this directly. Runners report the unpalatability of sweet foods during long efforts and show a shift in preference away from heavy sweetness in the later stages of a race. This is not weakness or poor discipline. It is predictable physiology, and it arrives for almost everyone who goes long enough.
When it arrives, fueling stops. And when fueling stops in a long race, the race usually ends badly.
The Evidence That Sweetness Is the Problem
The failure is specific. It is not fuel that your body rejects. It is the sweetness carrying it.
The clearest demonstration comes from a study in the Journal of Applied Physiology, where trained cyclists completed a two-hour effort plus a time trial while fueling with either potato puree, a carbohydrate gel, or water. The potato and the gel performed identically, and both beat water. The carbohydrate did its job regardless of how it was delivered.
The researchers behind that work were explicit about why it mattered. High sweetness in sports gels can induce flavor fatigue, and having a less sweet option to increase carbohydrate availability during exercise is genuinely useful.
Read that carefully, because it reframes the whole problem. Your body does not need sugar to be sweet. It needs carbohydrate. The sweetness is a delivery choice, and over long distance it is a delivery choice that eventually breaks.
Why Long-Distance Runners Turn to Salt
There is a second half to this, and it is about sodium.
Over many hours, you lose a great deal of sodium through sweat. Sodium is the electrolyte lost in the largest amount, and it is the one that lets your body actually retain the fluid you drink. Late in a long effort, athletes commonly find that salty things are among the few intakes that still appeal.
That craving is not random. It runs alongside a real physiological need. The intake that still goes down late in a race tends to be the one that is not aggressively sweet and does carry salt, which is exactly the intake profile a depleted athlete needs.
The practical lesson is not that you should chase any one food. It is that your fueling should not be built entirely on a sweetness your palate will eventually reject, and it should carry sodium from the start.
Building on a Base That Does Not Fight Your Palate
This is where the base of your bottle matters.
BEAUNE is organic beef bone broth blended with coconut water. Two cans in a standard 24 fluid ounce bottle give you a base carrying 500 mg of sodium and 180 mg of potassium, plus protein, before you add anything.
The relevant quality here is what it tastes like. BEAUNE is only lightly sweet, with a slight salinity. It is not a sugar-forward drink. That is a deliberate difference from the gels and sports drinks that dominate endurance fueling, and it is the difference that matters when hour eight arrives and heavy sweetness has become intolerable.
You still need carbohydrate, and you still add it. But the foundation underneath it is low in sugar and carries salt, so your bottle is not stacking sweetness on top of sweetness for the entire race.
Ultra carbohydrate targets commonly reach seventy grams per hour or more from multiple carbohydrate sources, with sodium often eight hundred milligrams per hour or higher over a long hot day. The base gives you five hundred milligrams of that sodium up front. You add carbohydrate and the remaining sodium on top.
A note on the base's protein. It is a meaningful amount, which is useful over a long effort where some protein intake supports muscle preservation across many hours. It can also slow gastric emptying at the highest intensities, though ultra efforts run at lower relative intensity than a marathon, which generally makes protein easier to tolerate. As always, test it across long training runs, not on race day.
Practical Rules for Fueling Past the Sugar Wall
A few things follow directly from all of this.
Vary the sweetness of your fuel rather than relying on a single sweet source for the entire race. Rotating flavors and formats delays the point at which your palate rejects everything.
Build on a base that is not sugar-forward, so that the sweetness in your bottle comes from what you deliberately add rather than from the foundation itself.
Carry sodium from the start rather than trying to catch up on it once you feel bad. Sodium loss is continuous and so is the need to replace it.
And practice all of it in training. Flavor fatigue arrives on long efforts, which means you cannot discover your tolerance on race day. Nothing new on race day.
Key Takeaways
• Over long distance, fueling usually fails because sweetness becomes intolerable, not because carbohydrate stops working.
• This is sensory-specific satiety, a predictable physiological response, not a discipline problem.
• Research shows carbohydrate delivered in a less sweet form performs just as well as a sweet gel. The sweetness is a delivery choice, not a requirement.
• Sodium loss runs continuously across long efforts, and salty intakes often remain palatable when sweet ones do not.
• A two-can BEAUNE base carries 500 mg sodium and 180 mg potassium, and is only lightly sweet with a slight salinity rather than sugar-forward.
• Vary your sweetness, build on a base that is not sugar-forward, carry sodium from the start, and test everything in training.
Where This Leaves Us
The runners who fuel a long day well are not the ones with the strongest stomachs. They are the ones whose fueling does not depend on a single sweetness their body will eventually refuse.
That starts with what is at the bottom of the bottle. A sugar-forward base means every sip for the entire race is more of the thing your palate is slowly turning against. A base that is only lightly sweet, carries salt, and delivers five hundred milligrams of sodium before you add anything gives you somewhere to build from that will not fight you at hour eight.
Fuel your long day on a base that does not fight your palate.
BEAUNE Summary
Fueling over long distance commonly fails not because carbohydrate stops working but because sweetness becomes intolerable. This is sensory-specific satiety, a predictable physiological response documented in research on ultramarathon runners, who report the unpalatability of sweet foods and shift away from heavy sweetness in the later stages of long efforts. Published research also shows carbohydrate delivered in a less sweet form supports performance as effectively as a sweet gel, indicating that sweetness is a delivery choice rather than a fueling requirement.
Sodium loss runs continuously across long efforts, and salty intakes frequently remain palatable when sweet ones do not. A two-can BEAUNE base provides 500 mg of sodium, 180 mg of potassium, and protein, and is only lightly sweet with a slight salinity rather than sugar-forward. Athletes build on it toward long-distance targets of roughly 70 g carbohydrate and 800 mg sodium per hour by adding carbohydrate and additional sodium.
The base's protein supports muscle preservation across long efforts and is generally well tolerated at the lower relative intensities of ultra-distance racing, though it should be tested in training. Used this way, BEAUNE is a foundation that does not compound the sweetness athletes eventually reject.
Sources
Tiller NB et al. International Society of Sports Nutrition Position Stand: Nutritional Considerations for Single-Stage Ultra-Marathon. Journal of the International Society of Sports Nutrition.
Costa RJS et al. The Impact of Gastrointestinal Symptoms and Dermatological Injuries on Nutritional Intake During Ultramarathon. International Journal of Sport Nutrition and Exercise Metabolism.
Salvador AF et al. Potato Ingestion Is as Effective as Carbohydrate Gels to Support Prolonged Cycling Performance. Journal of Applied Physiology.
Baker LB. Sweating Rate and Sweat Sodium Concentration in Athletes. Sports Medicine.
American College of Sports Medicine. Position Stand: Exercise and Fluid Replacement. Medicine and Science in Sports and Exercise.