How many energy gels do I need? Guide by distance for cycling and trail running

One of the most common questions before a race: how many gels do I actually need? Take too few and you bonk. Take too many and your stomach rebels. The answer depends on three things: distance, duration and intensity.

This guide gives you the numbers for cycling and trail running, with practical examples you can apply directly to your next race.

The basic rule: one gel every 30–45 minutes

The general guideline for endurance sports is one gel every 30–45 minutes once you're past the first hour of effort. Before that, your glycogen stores are sufficient and you don't need external carbohydrates.

This translates to 40–60g of carbohydrates per hour — the recommended range for most athletes in efforts under 2.5 hours. For longer efforts, you can push to 60–90g per hour if your gut is trained for it.

With PICO gels (40–47g carbs each), one per 45 minutes covers the standard recommendation comfortably.

Road cycling — how many gels by distance

60–90km (2–3h): 2–3 gels. Start at km 40–50, then every 45 minutes. Keep 1 in reserve for the final push.

90–130km (3–4h): 3–5 gels. Start at km 40, every 40–45 minutes. Combine with a bar or solid food around the halfway point to avoid gel fatigue.

130–180km (4–6h): 5–7 gels. After 3 hours, alternate gels with solids. Your gut needs variety on long efforts.

Gran Fondo / sportive (180km+): 7–10 gels minimum, complemented with real food at feed stations. Plan one gel every 40 minutes and adjust based on perceived effort.

Mountain biking — the intensity variable

MTB is more complex because intensity varies dramatically between climbs and descents. On a 3-hour trail ride with 1,500m of elevation, your average heart rate might be similar to a road ride — but the peaks are higher and the gut gets more physical stress from the vibration.

2–3h XC or trail ride: 2–3 gels. Take them on descents or flat sections, never mid-climb when blood flow to the gut is at its lowest.

Marathon MTB (4–6h): 4–6 gels, alternating with energy bars. Hydration becomes critical — always wash gels down with water.

Trail running — how many gels by distance

Half marathon trail (21km, 1.5–2.5h): 1–2 gels. One at km 7–8, one at km 14–15 if the effort continues past 1.5 hours.

Marathon trail (42km, 3–5h): 3–5 gels. Start at km 10, every 35–40 minutes. After km 30, have one ready every 30 minutes — the final section is where glycogen critically drops.

Ultra 50–80km (5–8h+): 6–10 gels, combined with real food at aid stations. In ultras, digestive tolerance becomes the limiting factor — natural gels without maltodextrin make a measurable difference from hour 4 onwards.

Ultra 100km+ (10h+): Gels are just one part of the nutrition strategy. Plan 1 gel per hour as the base, and complement with solids, broths and whatever your gut accepts. After 8 hours, many runners can't tolerate sweet flavours — salty options become critical.

Road running — marathon and beyond

Half marathon (sub-1:45): 1 gel at km 10. Short enough that glycogen stores cover most of the distance.

Half marathon (1:45–2:15): 2 gels. At km 8 and km 16.

Marathon (sub-3:30): 4–5 gels. Every 7–8km from km 10. The wall hits around km 30–32 — have a gel ready before you feel you need it.

Marathon (3:30–4:30): 5–6 gels. Every 35–40 minutes from km 10. At this pace, glycogen depletion is the main enemy.

The golden rule: test in training, never race

The worst time to discover a gel doesn't agree with you is kilometre 25 of a marathon. Test your gel strategy in long training sessions that replicate race conditions — same intensity, same timing, same hydration.

With natural gels like PICO, digestive tolerance is rarely the problem. But the timing, the quantity and the combination with hydration need practice.

Why PICO works for any distance

40–47g of carbohydrates per gel, 2:1 glucose-to-fructose ratio, no maltodextrin, no artificial additives. Dense texture that absorbs gradually — no spike, no crash.

Whether you need 2 or 10, the formula is the same: real ingredients that your body recognises at kilometre 1 and at kilometre 80.

Discover the PICOS — start with the Tasting Pack for €8.50 →