Energy gels deliver concentrated carbohydrate in a small package that is easy to carry during running, cycling and triathlon. They are convenient, not magical. A gel supports performance when the session is long or hard enough to require fuel, and when the athlete can absorb it without overwhelming the stomach.
Most standard gels contain roughly 20–30 g of carbohydrate. For exercise lasting 60–150 minutes, many athletes aim for 30–60 g of carbohydrate per hour. Longer events may justify 60–90 g/h after gut training. Take gels in small planned doses, usually with water unless the product is explicitly isotonic, and practise before race day.
What is an energy gel?
A gel is a concentrated mixture of carbohydrates, water, flavouring and sometimes sodium, caffeine or amino acids. Common carbohydrate sources include maltodextrin, glucose and fructose. Different transportable carbohydrates become increasingly useful at higher hourly intakes.
How to read an energy-gel label
| Label item | Why it matters |
|---|---|
| Carbohydrate | Determines how many gels are needed for the hourly target |
| Serving size | Some packets contain more than one serving |
| Caffeine | Must be counted across all food, drink and supplements |
| Sodium | May contribute to a hydration plan but varies widely |
| Carbohydrate types | Glucose-fructose combinations may support higher intake |
| Water instructions | Concentrated and isotonic gels are used differently |
When do you need an energy gel?
| Duration | Typical approach | Gel relevance |
|---|---|---|
| Under 60 min | Usually no carbohydrate needed when starting well fueled | Low |
| 60–90 min | Optional for hard sessions or racing | One gel may be useful |
| 90–150 min | 30–60 g carbohydrate per hour | Regular planned intake |
| Over 2.5–3 hr | Progress toward 60–90 g/h when tolerated | Combine gels with drinks or food |
Use How Many Carbs per Hour? to build the full target. Count grams rather than assuming every gel is identical.
When should you take gels?
For a long event, begin fueling early—often within the first 20–30 minutes—and continue at regular intervals. Waiting until energy collapses makes recovery difficult. A 60 g/h plan could use one 30 g gel every 30 minutes, or one gel plus carbohydrate drink.
Low target
One 25–30 g gel each hour, supported by water.
Moderate target
One 25–30 g gel every 30 minutes, or gels plus drink.
High target
Requires multiple carbohydrate sources and gradual gut training.
How much water should you drink with a gel?
Follow the product instructions. Concentrated gels are generally easier to tolerate with water, but fluid needs depend on sweat rate and conditions. Do not force excessive water merely to match a gel schedule. Isotonic gels contain more water and may be designed for use without an additional drink, although total hydration still matters.
Concentrated gel plus concentrated drink can create a very high carbohydrate load in the stomach. Test the exact combination in training.
Why do gels cause stomach problems?
| Cause | What it feels like | Possible fix |
|---|---|---|
| Too much carbohydrate too quickly | Bloating, nausea | Reduce hourly intake and progress gradually |
| Too little water with concentrated gel | Heavy stomach, thirst | Take with water as directed |
| Drink mixed too strongly | Sloshing or nausea | Measure powder and bottle volume |
| Intensity too high | Intake becomes difficult | Lower pace or use smaller doses |
| Heat and dehydration | Loss of appetite, nausea | Cool and adjust fluid strategy |
| Caffeine overload | Jitters, urgency, nausea | Count total dose and use non-caffeinated gels |
| Ingredient intolerance | Repeated symptoms with one product | Test another formula or food source |
How to train your gut
-
Start with 30–40 g/h
Use a familiar long session at moderate intensity.
-
Repeat the same products
Change only one variable at a time so symptoms are interpretable.
-
Add 10–15 g/h
Progress only after the previous amount is comfortable.
-
Test race intensity
Tolerance at easy cycling may not equal tolerance while running hard.
-
Rehearse timing and storage
Practise opening packets, carrying waste and drinking under race conditions.
Example six-week gut-training progression
| W | Target | Session |
|---|---|---|
| 1 | 30 g/h | 90 min easy bike |
| 2 | 40 g/h | 2 hr endurance bike |
| 3 | 50 g/h | 2 hr bike with steady blocks |
| 4 | 50–60 g/h | Long run or brick at controlled effort |
| 5 | 60–75 g/h | Race-specific long bike |
| 6 | Target race plan | Full rehearsal with exact products |
Do not continue increasing when symptoms worsen. Some athletes never need 90 g/h, and running tolerance is often lower than cycling tolerance.
Caffeinated vs non-caffeinated gels
Caffeine can support endurance performance, but total dose matters. Check every gel, drink, coffee and pre-workout product to avoid accidental stacking. A practical approach is to use non-caffeinated gels for most intake and add caffeine deliberately later in a race.
| Strategy | Advantage | Risk |
|---|---|---|
| All non-caffeinated | Simple and lower side-effect risk | No planned stimulant benefit |
| One caffeinated gel late | Controlled dose and timing | May be too late if unfamiliar |
| Alternating gels | Gradual intake | Total dose can be forgotten |
| All caffeinated | High total dose | Greater risk of nausea, jitters and sleep disruption |
Read Caffeine for Endurance Athletes.
Gels for running, cycling and triathlon
Running
Impact reduces tolerance. Small frequent doses and water are often easiest.
Cycling
Carrying and consuming fuel is easier, making the bike ideal for larger intake.
Triathlon
Fuel sufficiently on the bike without arriving at T2 with an overloaded stomach.
Example gel strategies by event
| Event | Example approach |
|---|---|
| 5K | Usually no gel needed during the race |
| 10K | Usually no gel; optional pre-race carbohydrate |
| Half marathon | One gel every 30–45 min depending on target |
| Marathon | Planned intake from early in the race, often 40–75+ g/h |
| Long cycling event | Gels plus drink and solid food for variety |
| Half Ironman | Higher intake on bike, smaller frequent run doses |
| Ironman | Mixed sources and careful caffeine timing |
These are examples, not prescriptions. Body size, intensity, duration and tolerance matter.
Alternatives to energy gels
Sports drink, chews, bananas, rice cakes, low-fibre bars and other familiar foods can provide carbohydrate. Long events often benefit from texture and flavour variety. Gels are most useful when speed, portability and precise counting matter.
Gels
Portable and precise, but concentrated and repetitive.
Sports drink
Combines fluid and carbohydrate, but concentration changes with mixing.
Chews
Easy to divide into small doses, but require chewing.
Real food
Provides variety and satisfaction, but can be harder to carry and digest at high intensity.
Race-day practical tips
- Pre-open packets only when they will not leak.
- Know where each gel is stored and how many are available.
- Secure empty wrappers rather than dropping litter.
- Carry one backup serving where practical.
- Separate caffeinated and non-caffeinated products clearly.
- Do not rely on aid-station flavours you have never tested.
Common energy-gel mistakes
Waiting until energy collapses
Fueling is more effective when started early.
Counting packets, not grams
Gel carbohydrate content varies substantially.
Ignoring drink carbohydrate
Total hourly intake may be much higher than planned.
Testing only on easy rides
Running and race intensity can change tolerance.
Accidental caffeine stacking
Multiple products can create an unexpectedly high dose.
Trying a new gel on race day
Flavour, texture and ingredients should be rehearsed.
Frequently asked questions
How many gels per hour?
Usually one to three depending on gel size and total carbohydrate target. Read the label.
Can I take a gel before running?
Yes, particularly before a hard or long session, but it is not a substitute for adequate meals.
Do energy gels expire?
Yes. Follow the date and storage instructions, and discard damaged packaging.
Can I race without gels?
Yes. Any tolerable carbohydrate source can work when it meets the practical target.
Do I need water with every gel?
Follow the product instructions. Concentrated gels generally pair well with water, while isotonic gels may be designed differently.
Why do gels make me nauseous late in races?
Heat, dehydration, rising intensity, excessive concentration and flavour fatigue can all reduce tolerance.
Final verdict
Energy gels are a precise and portable way to fuel endurance exercise. Read the label, count total carbohydrate and caffeine, begin early enough, use water appropriately and build tolerance in training. The best gel is the one you can consume repeatedly without compromising pace or stomach comfort.
Carbohydrate recommendations are informed by the joint position statement Nutrition and Athletic Performance. Persistent gastrointestinal symptoms should be discussed with an appropriate clinician or sports dietitian.
