When should I take energy gels?

Start taking gels 30-45 minutes into a ride, then every 20-30 minutes depending on intensity. Always take with water (unless they are isotonic gels). Do not wait until you feel depleted.

How many carbs per hour can I absorb?

The gut can absorb 60g/hr of a single carb source (glucose/maltodextrin). Using dual-source gels (glucose + fructose) allows absorption up to 90-120g/hr for trained athletes.

Should I use caffeine gels?

Caffeine (1-3 mg/kg) improves endurance performance. Save caffeinated gels for the second half of a ride or before a hard effort. Do not exceed 200-300 mg total caffeine per ride.

What about isotonic gels?

Isotonic gels (e.g., SIS Go, Maurten) do not require water to be consumed alongside them. Standard gels should always be taken with 200-300 ml of water to aid absorption and prevent GI issues.

Can I use food instead of gels?

Absolutely. Bananas (25g carbs), jam sandwiches (30g), fig rolls (10g each), and flapjacks all work well. Gels are just more convenient for higher intensities when eating solid food is difficult.

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Energy Gel Calculator — How Many Gels for Your Ride

Calculate how many energy gels to carry for your ride duration and intensity.

Ride Duration

Total planned ride time in minutes — the main driver of how many carbs you need

IntensitySecondary modifier — nudges the duration-led carb target up or down within the band

Carbs Per Gel

Carbohydrate per gel sachet (GU ~22 g, SIS Go ~22 g, Maurten Gel 100 ~25 g, SIS Beta Fuel ~40 g)

Start Fuelling At

Minutes into the ride before your first gel — start early (30-45 min) to bank carbs ahead of depletion

Other Carb Sources

Carbs per hour from bars, drink mix or food — subtracted from the gel total

How We Calculate This

Gel Requirement Calculation

Carb target is set mainly by ride duration (Jeukendrup 2014): ~30 g/hr up to 2 h, ~60 g/hr for 2–3 h (the single-source glucose ceiling), up to ~90 g/hr for rides over ~3 h using a 2:1 glucose:fructose blend. Intensity is a secondary modifier within the band.
Total carbs needed = Carbs/hr × whole ride duration (the per-hour target applies across the entire ride, not just after your first gel)
Carbs from gels = Total needed − Carbs from other sources (bars, drink mix, food)
Gels needed = Carbs from gels ÷ Carbs per gel, rounded up
Gel interval spreads the gels evenly from your first-gel time to the end of the ride

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.