Triathlon and Running Nutrition Calculator

How to use the calculator

Start with the Needs tab to frame your carbohydrate, fluid and sodium intakes from duration and conditions. Move to the Product plan to convert your target into gels, drink and bars. The Sweat tab helps personalize hydration through a simple field test.

How many carbs per hour?

For efforts under one hour, carbs stay optional: 0 to 30 g/h is enough. Between 1 and 2 h 30, target 30 to 60 g/h. Beyond that, climb to 60 to 90 g/h, and up to 90 to 120 g/h on very long events if your gut is trained. To exceed 60 g/h, combine multi-transportable carbs (glucose and fructose, often 2:1 ratio) to saturate several absorption pathways. The gut adapts with training: rehearse high intakes on long sessions weeks before the race. On hard efforts, sit at the top of the range; in steady endurance, the middle is enough.

Hydration and sodium

In temperate conditions, 400 to 700 ml/h cover most athletes, with 300 to 600 mg of sodium per hour. In hot conditions, climb to 600 to 1000 ml/h and 500 to 1000 mg of sodium per hour. Drinking large volumes of plain water without sodium raises the risk of hyponatremia on long events, which is why sports drinks and salt capsules help. Personalize through your sweat rate, which varies a lot between athletes.

Test before race day

Nothing new on race day: validate every product and intake cadence on your long sessions and bricks. Note what sits well and what does not, and tune quantities week after week.

Related resources

• Long-distance fueling
• All training resources