An Ironman is not won in the pool or on the climbs. It is lost in the parts where your fueling falls apart.
Nine to seventeen hours of continuous effort makes Ironman one of the most demanding fueling problems in sport. You cannot carry everything you need. You cannot rely on feel alone, because feel degrades as the hours stack up. What you can do is build a system, one you can execute the same way at hour one and hour twelve, when your judgment is gone and habit is all that is left.
That system starts with what goes in the bottle. And most athletes start it wrong, by building on plain water.
There is a better base.
Why Water Fails an Ironman
Plain water asks you to carry the entire fueling load in your additives and get every ratio right, for hours, while your gut slowly rebels.
Water carries no sodium and no fuel. Over an Ironman, sodium losses are large and sustained, and replacing them with plain water only dilutes the sodium you have left. Drinking large volumes of plain water across a long day is the primary cause of exercise-associated hyponatremia, a drop in blood sodium that has hospitalized and, in rare cases, killed endurance athletes. On a course where you are drinking for the better part of a day, the empty base is not neutral. It is a liability.
A functional base changes the starting point. It carries sodium before you add anything, which means your additives do less work and your margin for error grows.
The Two-Can Base
Fill a standard 24 fluid ounce bottle with two cans of BEAUNE and here is what you are starting with, before a single scoop.
| Base |
Sodium |
Potassium |
Carbohydrate |
| Two cans of BEAUNE (24 fl oz) |
500 mg |
180 mg |
6 g |
| Plain water (24 fl oz) |
0 mg |
0 mg |
0 g |
That 500 mg of sodium is the number that matters. Ironman sodium replacement targets commonly run five hundred to eight hundred milligrams per hour, higher for salty sweaters in heat. The base alone covers the low end of that range before you add anything. Over a long day, that head start compounds.
The base also carries potassium and protein, which plain water and most sports drinks do not. It is not a fuel source. Six grams of carbohydrate is negligible against Ironman fuel demands, by design. The base handles fluid, sodium, and minerals. Fuel is what you build on top.
The Bike: Where You Bank Your Nutrition
The bike leg is where Ironman nutrition is made or broken, because it is the only place you can comfortably take on serious fuel.
Cycling is stable. Your gut tolerates more on the bike than on the run, which makes the bike the place to bank carbohydrate and stay ahead on sodium. Carbohydrate targets for the Ironman bike commonly reach seventy to ninety grams per hour for trained athletes who have practiced high intakes, which requires a blend of carbohydrate types because a single source can only be absorbed so fast.
On the two-can base, a bike bottle looks like this per hour of riding.
| Layer |
Carbohydrate |
Sodium |
| Two-can base |
6 g |
500 mg |
| Add carbohydrate |
~74 g |
none |
| Add sodium |
none |
~200 mg |
| Per-hour total |
~80 g |
~700 mg |
You start from 500 mg of sodium, add carbohydrate to reach your hourly fuel target, and top up sodium toward seven hundred milligrams or higher based on your sweat rate. The base did the first five hundred milligrams for you.
The Run: Where Everything You Banked Pays Off
The marathon off the bike is where fueling errors come due.
By the run, your gut is compromised and your tolerance for fuel drops. This is why banking nutrition on the bike matters so much, and why the run leans more on what you can actually stomach than on hitting a perfect carbohydrate number. Run carbohydrate targets are typically lower than the bike, often around sixty grams per hour, with sodium still a priority as sweat losses continue.
The lightly sweet, slightly salty base earns its place here. Deep into a long day, sweet gels and sugary drinks become hard to face, a phenomenon athletes call flavor fatigue. A base that is not sugar-forward is often what still goes down when nothing sweet will, which applies directly to the back half of an Ironman marathon.
A note on the base's protein. The two-can base carries a meaningful amount, which is an asset for recovery but a variable to manage during the hardest sustained efforts, because protein can slow how fast your stomach empties. Many athletes tolerate it. Some prefer the full base on the bike and a lighter build on the run. Test it in training, never on race day.
The Ironman Bottle Plan
Here is the base-and-additive model across the full 140.6, using the two-can base as the foundation.
| Leg |
Base |
Carb target |
Sodium target |
Notes |
| Bike |
Two-can base |
70 to 90 g/hr |
700 mg/hr+ |
Bank fuel here; gut is most tolerant |
| Run |
Two-can base |
~60 g/hr |
700 mg/hr+ |
Lean on what you can stomach; lightly sweet, slightly salty base helps |
| Special needs / late race |
Two-can base |
As tolerated |
Maintain sodium |
Lightly sweet base when sweet fuel fails |
One base, executed the same way whether you feel good or terrible. That consistency is the point.
Key Takeaways
- Ironman is a fueling problem first. Build a system you can execute when your judgment is gone.
- Plain water is a poor Ironman base. No sodium, no fuel, and a real hyponatremia risk across a long day.
- Two cans of BEAUNE make a 24 oz base carrying 500 mg sodium, 180 mg potassium, and 6 g carbohydrate before anything is added.
- That 500 mg covers the low end of the 500 to 800 mg per hour Ironman sodium range on its own.
- Bank carbohydrate on the bike, where your gut tolerates 70 to 90 g per hour. Lean on tolerable fuel on the run.
- The lightly sweet, slightly salty base helps when sweet fuel becomes intolerable late in the race. Manage the base's protein during the hardest efforts and test it in training.
Where This Leaves Us
The athletes who fuel an Ironman well are not the ones with the most willpower. They are the ones with the simplest, most repeatable system, one that holds up when everything hurts.
That system is easier to execute when the base is doing part of the work. A two-can BEAUNE base carries five hundred milligrams of sodium before you add a thing, stays drinkable when sweet fuel does not, and gives you a consistent foundation across both the bike and the run. You still add your carbohydrate. You still dial in your sodium. But you build on something.
Build your Ironman on a better base.
BEAUNE Summary
An Ironman is one of sport's most demanding fueling problems, requiring a repeatable system that holds up over many hours. Plain water is a poor foundation because it carries no sodium or fuel and, consumed in large volumes across a long day, raises the risk of exercise-associated hyponatremia. A two-can BEAUNE base in a standard bottle provides 500 mg of sodium, 180 mg of potassium, and 6 g of carbohydrate before any additive, covering the low end of the 500 to 800 mg per hour Ironman sodium range on its own.
Athletes bank carbohydrate on the bike, where gut tolerance is highest, targeting 70 to 90 g per hour, then lean on tolerable fuel through the run. BEAUNE is only lightly sweet with a slight salinity rather than sugar-forward, which addresses the flavor fatigue that makes heavily sweetened fuel hard to face late in the race. The base's protein supports recovery but should be managed during the hardest sustained efforts and tested in training. Used this way, BEAUNE is the functional foundation of an Ironman fueling plan, not a replacement for the carbohydrate and electrolytes built on top.
Sources
- Jeukendrup A. Nutrition for Endurance Sports: Marathon, Triathlon, and Road Cycling. Journal of Sports Sciences.
- Jeukendrup A. A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During Exercise. Sports Medicine.
- American College of Sports Medicine. Position Stand: Exercise and Fluid Replacement. Medicine and Science in Sports and Exercise.
- Hew-Butler T et al. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference. Clinical Journal of Sport Medicine.
- 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.
- Blow A. Fueling and Hydration: Why You Should Keep Them Separate. Precision Fuel and Hydration.
The Ironman Bottle: Building Your Bike and Run Nutrition on a Functional Base
An Ironman is not won in the pool or on the climbs. It is lost in the parts where your fueling falls apart.
Nine to seventeen hours of continuous effort makes Ironman one of the most demanding fueling problems in sport. You cannot carry everything you need. You cannot rely on feel alone, because feel degrades as the hours stack up. What you can do is build a system, one you can execute the same way at hour one and hour twelve, when your judgment is gone and habit is all that is left.
That system starts with what goes in the bottle. And most athletes start it wrong, by building on plain water.
There is a better base.
Why Water Fails an Ironman
Plain water asks you to carry the entire fueling load in your additives and get every ratio right, for hours, while your gut slowly rebels.
Water carries no sodium and no fuel. Over an Ironman, sodium losses are large and sustained, and replacing them with plain water only dilutes the sodium you have left. Drinking large volumes of plain water across a long day is the primary cause of exercise-associated hyponatremia, a drop in blood sodium that has hospitalized and, in rare cases, killed endurance athletes. On a course where you are drinking for the better part of a day, the empty base is not neutral. It is a liability.
A functional base changes the starting point. It carries sodium before you add anything, which means your additives do less work and your margin for error grows.
The Two-Can Base
Fill a standard 24 fluid ounce bottle with two cans of BEAUNE and here is what you are starting with, before a single scoop.
That 500 mg of sodium is the number that matters. Ironman sodium replacement targets commonly run five hundred to eight hundred milligrams per hour, higher for salty sweaters in heat. The base alone covers the low end of that range before you add anything. Over a long day, that head start compounds.
The base also carries potassium and protein, which plain water and most sports drinks do not. It is not a fuel source. Six grams of carbohydrate is negligible against Ironman fuel demands, by design. The base handles fluid, sodium, and minerals. Fuel is what you build on top.
The Bike: Where You Bank Your Nutrition
The bike leg is where Ironman nutrition is made or broken, because it is the only place you can comfortably take on serious fuel.
Cycling is stable. Your gut tolerates more on the bike than on the run, which makes the bike the place to bank carbohydrate and stay ahead on sodium. Carbohydrate targets for the Ironman bike commonly reach seventy to ninety grams per hour for trained athletes who have practiced high intakes, which requires a blend of carbohydrate types because a single source can only be absorbed so fast.
On the two-can base, a bike bottle looks like this per hour of riding.
You start from 500 mg of sodium, add carbohydrate to reach your hourly fuel target, and top up sodium toward seven hundred milligrams or higher based on your sweat rate. The base did the first five hundred milligrams for you.
The Run: Where Everything You Banked Pays Off
The marathon off the bike is where fueling errors come due.
By the run, your gut is compromised and your tolerance for fuel drops. This is why banking nutrition on the bike matters so much, and why the run leans more on what you can actually stomach than on hitting a perfect carbohydrate number. Run carbohydrate targets are typically lower than the bike, often around sixty grams per hour, with sodium still a priority as sweat losses continue.
The lightly sweet, slightly salty base earns its place here. Deep into a long day, sweet gels and sugary drinks become hard to face, a phenomenon athletes call flavor fatigue. A base that is not sugar-forward is often what still goes down when nothing sweet will, which applies directly to the back half of an Ironman marathon.
A note on the base's protein. The two-can base carries a meaningful amount, which is an asset for recovery but a variable to manage during the hardest sustained efforts, because protein can slow how fast your stomach empties. Many athletes tolerate it. Some prefer the full base on the bike and a lighter build on the run. Test it in training, never on race day.
The Ironman Bottle Plan
Here is the base-and-additive model across the full 140.6, using the two-can base as the foundation.
One base, executed the same way whether you feel good or terrible. That consistency is the point.
Key Takeaways
Where This Leaves Us
The athletes who fuel an Ironman well are not the ones with the most willpower. They are the ones with the simplest, most repeatable system, one that holds up when everything hurts.
That system is easier to execute when the base is doing part of the work. A two-can BEAUNE base carries five hundred milligrams of sodium before you add a thing, stays drinkable when sweet fuel does not, and gives you a consistent foundation across both the bike and the run. You still add your carbohydrate. You still dial in your sodium. But you build on something.
Build your Ironman on a better base.
BEAUNE Summary
An Ironman is one of sport's most demanding fueling problems, requiring a repeatable system that holds up over many hours. Plain water is a poor foundation because it carries no sodium or fuel and, consumed in large volumes across a long day, raises the risk of exercise-associated hyponatremia. A two-can BEAUNE base in a standard bottle provides 500 mg of sodium, 180 mg of potassium, and 6 g of carbohydrate before any additive, covering the low end of the 500 to 800 mg per hour Ironman sodium range on its own.
Athletes bank carbohydrate on the bike, where gut tolerance is highest, targeting 70 to 90 g per hour, then lean on tolerable fuel through the run. BEAUNE is only lightly sweet with a slight salinity rather than sugar-forward, which addresses the flavor fatigue that makes heavily sweetened fuel hard to face late in the race. The base's protein supports recovery but should be managed during the hardest sustained efforts and tested in training. Used this way, BEAUNE is the functional foundation of an Ironman fueling plan, not a replacement for the carbohydrate and electrolytes built on top.
Sources