The Role of Carbohydrates in a Cyclist's Diet — How Much, When, and What Kind

Carbohydrates are the first fuel your body reaches for during exercise. For cyclists they matter more than for almost any other athlete — multi-hour rides drain glycogen stores like nothing else.

How many carbs does a cyclist need?

ActivityCarbs (g/kg body weight/day)
Rest day3–5 g/kg
Moderate training (1–2 h)5–7 g/kg
Hard training (2–4 h)7–10 g/kg
Extreme (4+ h, racing)10–12 g/kg

For a 75 kg cyclist, that's 375–750 g of carbs a day on training days. Sounds like a lot? It is — cycling is an energy-hungry sport.

Timing — when to eat

Before training (2–3 h out)

A meal rich in complex carbs: oatmeal, rice, pasta, whole-grain bread. The goal: top off glycogen stores. Avoid a lot of fiber — it can cause GI discomfort.

During training (over 90 min)

30–60 g of carbs per hour — gels, bars, bananas, dates. For efforts over 3 hours: up to 90 g/h (requires gut training and a glucose-fructose blend).

After training (0–2 h)

The recovery window — 1–1.2 g/kg body weight of carbs plus protein. A shake with banana, oats, and milk is a classic. The goal: replenish glycogen before your next session.

Simple vs. complex carbs

Don't demonize simple sugars — during exercise your body needs fast-available energy. An energy gel during a 4-hour ride isn't "unhealthy sugar," it's fuel.

Carbo-loading before a race

Carb-loading before an important event is a proven strategy: 3 days out, increase carb intake to 10–12 g/kg while reducing training volume. Glycogen stores rise by 20–40%, which translates to noticeably longer endurance.

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