A gel can help you maintain marathon pace, but taking a non-isotonic gel without enough water may leave you nauseated, bloated, or unable to fuel. The problem becomes harder when the next aid station is crowded or farther away than expected. Learning how to take non-isotonic gels with water during a marathon means planning the gel, the fluid, and the timing as one action—not treating them as separate tasks.
Quick Answer
Take a non-isotonic gel with water, not a mouthful of sports drink, unless the product label specifically says otherwise. A practical starting point is about 150–250 ml of plain water with a standard gel, taken in several swallows over a minute or two.
Plan to take the gel shortly before an aid station, then collect water immediately afterward. If stations are difficult to reach, carry a small soft flask so the gel does not depend on perfect station timing. Do not wait until you are thirsty, and do not chase a gel with a large amount of fluid all at once.
Check the label first. Some gels are designed to be consumed with water, while isotonic or hydrogel products may require less additional fluid. Higher-carbohydrate gels also commonly need more water than smaller gels.
Why This Happens
A gel is a concentrated source of carbohydrate. It contains much less water than a sports drink, so your stomach must dilute it before it can move comfortably through digestion. When a concentrated gel is taken with too little fluid, the mixture can sit heavily in the stomach and draw water into the gut. That may contribute to nausea, cramping, sloshing, or diarrhea during a hard effort.
This does not mean every gel needs exactly the same amount of water. The required volume depends on the gel size, carbohydrate concentration, texture, your sweat rate, weather, pace, and what else you are drinking. A 20-gram gel and a 40-gram high-carbohydrate gel should not automatically be treated as identical.
Aid stations create a second problem: coordination. A runner may take a gel 30 seconds before a station, miss the first table, slow down to grab a cup, and then drink too quickly. The result is often more stressful than the original fueling plan. The solution is to use a repeatable sequence that works even when a station is crowded.
It is also easy to confuse isotonic with non-isotonic products. Isotonic gels are formulated with a higher water content and may be easier to take without a separate drink. Non-isotonic gels are usually thicker or more concentrated and are commonly intended to be followed by water. Packaging is the final authority, so read the directions and test the product in training.
Step-by-Step Method
1. Identify the gel’s fluid requirement
Before race day, check the nutrition panel and instructions. Look for serving size, carbohydrate grams, caffeine, and any statement about taking the gel with water. If the product is thick, contains a large carbohydrate dose, or clearly says to consume with water, treat it as a non-isotonic gel for planning purposes.
As a practical starting point, pair a standard concentrated gel with 150–250 ml of water. This is a planning range, not a medical rule. You may need less if you take the gel slowly and are also drinking regularly, or more if the gel is particularly concentrated and conditions are hot.
2. Map gels to aid stations before the race
Do not simply write down a goal such as one gel every 30 minutes. Mark where each gel will happen on the course map. Then identify the nearest reliable water source after each gel.
A useful race plan has three points:
- The time or distance when you will take the gel.
- The aid station where you will collect water.
- A backup plan if that station is missed.
Taking the gel 30–90 seconds before an aid station often works well. You can open and consume it while approaching the station, then take water as soon as you reach the tables. This gives you enough time to swallow without stopping and avoids carrying an opened gel through several kilometers.
3. Make the gel easy to open
Pinch or tear the top of the gel before the race becomes difficult. Some runners partially open gels and store them in a belt or shorts pocket. Practice this during training because a slippery packet is harder to manage when your hands are sweaty.
If you use a race-provided gel, check its flavor and texture in advance if possible. Do not make an unfamiliar gel your main source of carbohydrate on race day.
4. Slow down the intake
Take two or three squeezes, swallow, and continue over roughly 30–60 seconds. You do not need to force the entire gel down in one instant. A short reduction in pace is usually less damaging than keeping marathon effort high while your stomach is overloaded.
If the gel is very thick, take smaller amounts and follow with water. Avoid holding a large quantity in your mouth while trying to breathe hard. For runners who struggle with gels, a few smaller servings may be easier than one large serving, provided the total carbohydrate plan still makes sense.
5. Collect water without stopping abruptly
As you approach the station, move toward the side where the water tables are located. Choose the first practical table rather than aiming for a specific brand or flavor. Take one cup, pinch the top to reduce splashing, and drink several controlled swallows.
You do not have to finish the entire cup immediately. Carry it for a short distance and drink again if needed. If you miss the water, do not panic or take a second gel to compensate. Use your backup plan and wait for the next suitable opportunity.
6. Use a soft flask when the course demands it
A 150–250 ml soft flask can make fueling much easier on crowded courses or races with widely spaced stations. Carrying water lets you take a gel at the planned time instead of delaying it until a station appears.
A flask is especially useful when you know that you drink slowly, when the course is hot, or when your target pace makes grabbing cups difficult. The trade-off is extra weight and the need to refill. Do not carry a flask for the first time in a marathon. Test the grip, bite valve, belt, and pocket arrangement during long runs.
7. Separate concentrated carbohydrates when necessary
If you use several gels, carbohydrate drink, chews, or sports drink in the same period, your total intake may become too concentrated. Avoid stacking a gel and a large drink immediately together unless you have tested that combination.
A simple approach is to use water with concentrated gels and treat sports drink as part of your carbohydrate intake. You can alternate them rather than consuming every available product at every station.
8. Practice the complete sequence
During long runs, rehearse the exact routine: open the gel, take it while moving, drink the planned water volume, and continue at effort. Practice in the shoes, socks, belt, and clothing you expect to race in. Gear that bounces or rubs can turn a simple fueling plan into a distraction.
Test the routine at marathon effort, not only during easy running. Digestion can change when breathing is hard, so a gel that feels fine at a relaxed pace may feel different near race intensity.
Common Mistakes
Taking a non-isotonic gel with no water
This is the most direct route to a concentrated carbohydrate load in the stomach. Take the gel with plain water or carry enough water to follow it soon afterward.
Waiting until an aid station to decide
Last-second decisions lead to missed stations, rushed swallowing, and overdrinking. Assign each gel to a station before the race and choose a backup station in case the first one is crowded.
Drinking an entire cup too quickly
Large gulps can cause stomach sloshing, especially at marathon pace. Pinch the cup, take controlled swallows, and carry the remainder for a short distance if necessary.
Assuming every gel has the same fluid requirement
A small isotonic gel, a thick 40-gram gel, and a gel with added sodium are not interchangeable. Read each label and test the exact product you plan to use.
Taking gels only after you feel weak
By the time energy levels drop, it can be difficult to recover your rhythm. Start fueling according to a schedule that you have practiced, usually early enough that you are not relying on hunger or fatigue as a signal.
Changing the plan after one uncomfortable gel
Nausea may come from pace, heat, dehydration, too much carbohydrate, or a product that does not suit you. Do not automatically abandon all fueling. Review the amount, fluid, timing, and intensity, then change one variable at a time in training.
Checklist or Decision Table
| Situation | Practical choice | Water approach | Backup plan |
|---|---|---|---|
| Standard non-isotonic gel | Take before an aid station | About 150–250 ml in controlled swallows | Carry a small flask if the station is unreliable |
| Large carbohydrate gel | Take earlier and more slowly | Use the label guidance; usually prioritize plain water | Split the serving only if tested in training |
| Isotonic gel | Follow the product instructions | Additional water may be smaller, but regular hydration still matters | Do not assume every isotonic gel works the same |
| Hot or humid race | Fuel earlier and monitor drinking | Use water regularly without forcing excessive amounts | Carry fluid if stations are widely spaced |
| Crowded aid stations | Take the gel before entering the station | Grab the first available water and keep moving | Use the next station or a soft flask |
| Sports drink is your main fluid | Count its carbohydrate toward your total | Avoid automatically adding a full gel and full cup together | Use water with concentrated gels |
| Sensitive stomach | Use smaller, tested doses | Sip rather than gulp | Reduce pace briefly and avoid introducing new products |
Before the start, confirm that you know the gel flavor, serving size, caffeine content, opening method, planned intake points, water stations, and backup fluid option. This small checklist prevents many race-day decisions.
When This Advice Does Not Apply
The 150–250 ml range is not a universal prescription. Product directions may call for a different amount, and your personal tolerance may be lower or higher. Follow the label and use training to find your workable range.
Do not force fluid if you are already bloated, vomiting, confused, or unable to keep drinks down. Stop pushing the fueling plan and seek help from race medical staff if symptoms are severe or worsening. Persistent nausea, abdominal pain, repeated vomiting, or unusual weakness also deserves medical attention.
This guide cannot replace an individualized plan for diabetes, gastrointestinal disease, kidney or heart conditions, or medication-related fluid restrictions. Speak with an appropriately qualified clinician before changing carbohydrate or fluid intake for long races.
The advice also changes in extreme heat, cold, or very long events. Sweat losses and electrolyte needs vary considerably. Water helps dilute a concentrated gel, but it does not automatically replace sodium or other electrolytes lost through sweat.
Realistic Example
A recreational marathon runner plans to take a concentrated 40-gram gel at 35, 70, and 105 minutes. The first gel is taken just before a crowded aid station, but the runner misses the water table and continues for several kilometers. The gel feels heavy, and a second gel is taken early to compensate for fading energy. Nausea follows.
A better plan would be to identify the station before the race, take the first gel 60 seconds before reaching it, and carry a 200 ml soft flask as insurance. The runner could take half the gel while approaching the station, collect water, then finish the gel with controlled swallows. In training, the same sequence should be tested at marathon effort. If the full 40-gram serving still causes discomfort, the runner can test smaller servings or a different product rather than improvising during the race.
Final Takeaway
Treat a non-isotonic gel and its water as one fueling step. Check the label, practice the exact product, take the gel shortly before a reliable water point, and drink in controlled swallows rather than gulping.
The simplest decision rule is this: if the gel is concentrated or the label says to use water, plan plain water immediately after it. When aid stations are unpredictable, carry a tested soft flask. A fueling plan that works under pressure is more valuable than a theoretically perfect schedule that depends on catching every cup.
FAQs
How much water should you drink with a non-isotonic gel during a marathon?
Start with about 150–250 ml of plain water for a standard non-isotonic gel, then adjust based on the label and your training response. Drink in several swallows over roughly one to two minutes instead of forcing the entire amount at once. Larger or higher-carbohydrate gels may need more fluid, while regular drinking between gels also contributes to hydration. The right amount depends on pace, weather, sweat rate, and stomach tolerance. Test the exact gel-and-water combination during long runs before race day.
Should you take a non-isotonic gel before or after an aid station?
Take it shortly before an aid station when possible, then collect water immediately afterward. A gap of about 30–90 seconds gives you time to open and swallow the gel without stopping, while the station provides the fluid needed to dilute it. If you take the gel after the station, you may have to carry water or wait several kilometers for the next one. Always identify a backup station because crowds, spilled cups, or course congestion can make the nearest table difficult to use.
Can you take a non-isotonic gel with sports drink instead of water?
You can sometimes do so, but plain water is usually the safer default for a concentrated gel. Sports drinks already contain carbohydrate and electrolytes, so combining a full gel with a large serving may create a high carbohydrate concentration that your stomach has not practiced handling. Check the gel directions and count the drink as part of your total fueling. If you want to use sports drink with gels, test the exact combination during long runs and avoid adding every available product at the same aid station.
What should you do if you miss the aid station after taking a gel?
Do not panic or immediately take another gel. Keep moving at a manageable effort, use water from a soft flask if you carry one, and wait for the next practical station. If you have no fluid, avoid taking another concentrated gel until you can drink. A missed station is a reason to use your backup plan, not to double your intake. For future races, take gels closer to reliable stations, carry a small amount of water, or choose a course strategy that gives you more than one fluid option.
Are isotonic gels easier on the stomach than non-isotonic gels?
Isotonic gels may be easier for some runners because they contain more water and can require less additional fluid, but they are not automatically better for everyone. Texture, carbohydrate type, serving size, caffeine, pace, heat, and individual tolerance all affect digestion. A gel that feels comfortable during an easy run may still cause problems at marathon effort. Read the product instructions, use the same product repeatedly in training, and change only one variable at a time when troubleshooting nausea.
How can you practice taking gels without missing water during training?
Rehearse the full sequence on a long run: take the gel at a planned time, approach a known water source, drink the intended amount, and continue at race effort. You can use a bottle, fountain, parked car, or training partner to imitate an aid station. Practice opening packets while moving and test any belt or soft flask you will race with. Record the gel, water volume, timing, pace, temperature, and stomach response. That log helps you identify whether the problem is the product, concentration, timing, or effort.