How much should you eat and drink during a triathlon?

What numbers are useful starting points?

For longer exercise, carbohydrate is usually discussed in grams per hour. Thirty to sixty grams per hour is a common starting range, while longer or harder endurance events may use up to about ninety grams per hour when athletes have trained their intake and tolerate suitable carbohydrate sources.

Fluid needs vary widely. Estimate your own sweat rate across different conditions rather than copying one bottle-per-hour rule. Sodium needs also vary; sports drinks commonly include sodium to support palatability and fluid retention, but more is not automatically better.

How do you build a race fueling plan?

Start with the likely duration and the products available on course. Calculate what each bottle, gel, chew, or food portion actually contains. Build a simple hourly range, then test it during longer rides and bricks in conditions similar to the race.

Record what you consumed and how you felt. Change one variable at a time: concentration, timing, product, total carbohydrate, or fluid. The bike is often the easiest place to eat and drink, but the plan must leave your stomach comfortable enough to run.

Why can copying another athlete go wrong?

Two athletes can have different body sizes, sweat rates, sodium losses, speeds, weather, and gut tolerance. A plan that works for a fast, experienced athlete may provide too much intake or too little fluid for someone else.

Excess fluid can be dangerous, and aggressive sodium or carbohydrate intake can cause problems. A sports dietitian can help when the event is long, conditions are hot, or you have medical or gastrointestinal concerns.

Common triathlon fueling mistakes

Avoid trying a new product on race day, guessing serving sizes, mixing drink powder too strongly, forgetting what the course provides, and waiting until late in a long event to begin fueling. Do not treat thirst, cramps, or stomach symptoms as proof of one simple deficiency.

Keep reading

• Triathlon fueling app guide →
• Race-day checklist →
• Move from Olympic to 70.3 →

Sources and further reading

These references support the general guidance above. Your event's current athlete guide and advice from qualified professionals take priority for your race and health.

• Australian Institute of Sport: sports drinks
• Australian Institute of Sport: electrolyte use
• American College of Sports Medicine: fluid replacement

Frequently asked questions

How many carbohydrates per hour do I need?

For exercise longer than an hour, 30–60 grams per hour is a common starting range. Longer events may use higher intakes, but the amount and carbohydrate mix should be practised and personalised.

How much water should I drink during a triathlon?

There is no safe universal hourly number. Use training in similar weather to estimate sweat loss and tolerable intake. Avoid both excessive dehydration and drinking beyond your losses.

Do I need sodium during a triathlon?

Sodium can support fluid palatability and retention during prolonged exercise, but needs vary with sweat loss, duration, conditions, food, and drink. More sodium is not automatically safer or better.

Should I use gels, drink, or solid food?

Use products that deliver the planned carbohydrate and fluid in a form you tolerate and can carry or collect. Many athletes combine sources. Practise the exact mix before race day.