Key takeaway
Carbohydrate is a tool to match to the work: easy days need less targeted fuel than long or high-intensity sessions.
Why intensity changes the equation
As exercise intensity rises, carbohydrate becomes an increasingly important fuel. Liver and muscle glycogen stores are limited, so long or demanding sessions can benefit from carbohydrate before and during exercise.
Before and during training
A carbohydrate-rich meal one to four hours before a key session can support available fuel. Closer to exercise, smaller and lower-fibre choices may be more comfortable.
For prolonged exercise, commonly used starting ranges are around 30–60 g carbohydrate per hour. Higher intakes, sometimes up to 90 g per hour, require progressive practice and suitable mixed carbohydrate sources.
Train the gut
Gastrointestinal tolerance is trainable. Test product type, concentration, fluid pairing and timing during sessions that resemble the event. Do not introduce an ambitious fuelling plan on race day.
Use this information in context
This article is general education for adults. It is not a diagnosis, treatment plan or individualized medical nutrition advice. See the methodology and references and the nutrition disclaimer.