Energy gels and chews deliver 20–25 g of fast-digesting carbohydrates per serving and do work on trail — but only when you are working hard enough to need rapid glucose delivery. For moderate day hikes under 4 hours, whole-food snacks are equally effective and far cheaper. Above 4 hours of sustained moderate-to-vigorous effort, gels help you hit the 60 g/hour carbohydrate absorption target that sports science consistently links to maintained endurance performance.
How Do Energy Gels Work During Exercise?
Energy gels are concentrated solutions of fast-absorbing sugars — typically a blend of maltodextrin and fructose in a 2:1 ratio. This combination engages two separate intestinal transport pathways simultaneously, allowing the gut to absorb more carbohydrate per hour than a single-sugar formula. Sports science research from the University of Birmingham's Human Performance Laboratory — led by Professor Asker Jeukendrup over more than a decade — has consistently shown that 2:1 maltodextrin-fructose gels improve endurance performance by 8–10% compared to glucose-only formulations in exercise bouts over 90 minutes. For hiking, where intensity is lower and duration longer than a cycling time trial, the practical ceiling for most hikers is 45–60 g of carbohydrates per hour before gut discomfort limits absorption.
The critical difference between gels and whole foods is delivery speed: a gel's simple sugars enter the bloodstream within 5–10 minutes, while a banana or energy bar takes 20–30 minutes. On a flat walk, this lag doesn't matter. On a sustained summit push or a 10-hour mountain day, the 20-minute gap between eating and feeling the energy effect can tip you into an energy crash. Our guide to avoiding bonking on long hikes covers the full energy management strategy, of which gels are one component.
Energy Gels vs Chews vs Real Food: Which Is Best for Hiking?
Energy Gels
Gels (22–27 g carbs per 40–45 g packet) are the fastest-delivering format and the most consistent for dose control. They require water to digest properly — taking a gel without at least 150 ml of water is the most common cause of nausea and GI cramps on trail. Best used during sustained climbs or high-mileage days where precise energy timing matters. Caffeine gels (typically 50–100 mg per packet) add an alertness boost useful in the final hours of a long day.
Energy Chews
Chews (18–22 g carbs per 3–6 piece serving) are the most palatable format for most hikers — their solid texture satisfies the urge to chew and they're less prone to nausea than gels. Delivery is slower by 5–10 minutes. More easily portioned in small amounts, making them better for moderate-intensity hiking where you want a steady supplement rather than a rapid spike.
Real Food Alternatives
For hikes under 6 hours at moderate intensity, dates, rice cakes with nut butter, gummy bears (23 g carbs per 100 g) and oat flapjacks deliver carbohydrates effectively at a fraction of the cost. The trade-off is slower absorption and more bulk per calorie. Our nutrition timing guide covers how to combine real food and gels for optimal all-day energy management on long trail days.
Best Energy Gels and Chews for Hiking 2026
| Product | Carbs | Caffeine | Kcal | Price | Best For |
|---|---|---|---|---|---|
| Maurten Gel 100 | 25 g | No | 100 | £3.50 | Sensitive stomachs |
| SiS GO Isotonic Gel | 22 g | Optional (75 mg) | 87 | £1.60 | No extra water needed |
| GU Energy Gel | 22 g | Optional (20–40 mg) | 100 | £1.50 | Best value per gram carb |
| Huma Chia Energy Gel | 21 g | No | 90 | £2.20 | Real-food ingredient fans |
| Clif Bloks Energy Chews | 24 g | Optional (50 mg) | 100 | £2.00 | Best texture and palatability |
Hydration When Using Gels on Trail
Gels require adequate water — without it they sit in the gut as an unabsorbed syrup and cause the nausea and cramps that give gels a bad reputation among hikers. The minimum water volume per gel is 150 ml (three average mouthfuls from a 500 ml bottle). SiS GO Isotonic gels are formulated as a pre-diluted solution and can be taken without extra water — the most practical option when water sources are scarce or when stopping to drink is difficult on a technical scramble.
For remote mountain routes, maintaining hydration for effective gel use demands reliable water access. The Katadyn BeFree 1L filter bottle (55 g) allows drinking directly from streams without stopping to fill a separate container — the fastest field filtration system available at that weight. For situations where streams may be contaminated by livestock or glacial outflow, the SteriPen Adventurer Opti UV purifier (80 g) treats 0.5 L in 48 seconds using UV light, with no physical filter to clog. Tracking your hydration and effort level helps calibrate gel timing — the Garmin Instinct 2 Solar measures heart rate continuously and its Body Battery metric reflects real-time energy status, signalling when you need to fuel before you feel it. For a deep look at caffeine gels specifically, see our guide to caffeine and hiking performance.
Frequently Asked Questions
When should I take an energy gel on a hike?
Take your first gel at the 60–90 minute mark of a sustained hard effort — before you feel depleted. Gels take 5–10 minutes to raise blood glucose, so waiting until you feel empty means you are already behind the curve. On extended summit days, aim for one gel or equivalent every 45–60 minutes during the main climbing sections.
Do energy gels cause stomach problems on trail?
GI distress from gels most often results from taking them without enough water, at too high a frequency, or when gut blood flow is already compromised by heat and dehydration. Hydrogel-format products (Maurten, Precision Hydration) are significantly better tolerated in athletes with sensitive guts. Start with half a gel per session to test tolerance before relying on them on a high-stakes day.
Are energy gels worth the cost compared to real food?
For most day hikes under 6 hours, no — dates, gummy bears or oat bars deliver identical carbohydrates at under £0.50 per serving versus £1.50–£3.50 for a single gel. For sustained high-effort days over 6 hours, technical terrain requiring precise pacing, or thru-hike start days, the dose precision and delivery speed of gels justifies the cost.
Can I use running or cycling energy gels for hiking?
Yes — the formulation is identical regardless of the sport shown on the packaging. Choose based on your carbohydrate target per serving (22–27 g is the sweet spot for hourly fuelling), caffeine preference and gut tolerance. The sport-specific branding is purely marketing.