For a full marathon in Singapore, plan to carb load for the last 2 to 3 days, eat a light, familiar breakfast 2 to 4 hours before the start, then take in 30 to 60 g of carbohydrate per hour during the race. Trained runners can build toward 90 g per hour. Add fluids and sodium to match your sweat rate, and rehearse the whole plan in warm, humid training runs. We walk through each step below, so you can show up on race morning with a plan you have already tested.
TL;DR
- Final days: carb load for 2 to 3 days with simple, low-fiber, familiar foods.
- Race morning: a light breakfast 2 to 4 hours before the start, then small top-ups of fluid and a gel about 15 minutes before.
- During the race: 30 to 60 g of carbohydrate per hour, up to 90 g per hour if your gut is trained and your gels mix glucose and fructose.
- Heat: 400 to 800 ml of fluid per hour depending on sweat rate, plus sodium. Never drink more than you sweat.
- Practice: rehearse the exact plan in warm, humid long runs. Nothing new on race day.
Table of Contents
- Why Singapore changes the plan
- Carb loading: the last 2 to 5 days
- Race morning: breakfast and the hydration timeline
- Fueling during the race: how many grams per hour
- Fluids and sodium in the heat
- Train your gut before race day
- Our perspective
- Pick your products from Racepack
- Practical tips for the final week
- FAQ
- Sources
Why Singapore changes the plan
The carbohydrate numbers for a marathon are the same everywhere. What Singapore changes is how your stomach and sweat rate cope with them. One Singapore race guide points out that heat and humidity do not change the carb targets but make a full stomach feel worse, which is why rehearsing in warm, humid conditions matters more than tweaking the grams.
The same guide reports typical December conditions of a daily low around 24.3°C and a high around 30.5°C, with relative humidity usually above 90% just before sunrise. You start sweating early and keep sweating. That makes fluids, sodium and a steady carbohydrate drip the three pillars of your plan.
Our Singapore coach’s 36 to 48 hour plan for humid races covers the final two days in more detail. Here is the full picture from the first carb-loading meal to the finish line.
Carb loading: the last 2 to 5 days
Carb loading means topping up your muscle glycogen so you start with full tanks. Timelines vary by source. Cleveland Clinic advises that carb loading typically starts 3 to 5 days ahead of the marathon, with simple, low-fiber carbohydrate foods such as white pasta, rice, bread and low-fiber fruits, and familiar foods only. Another approach is 2 to 3 days at 8 to 12 g of carbohydrate per kg of body weight per day, which for a 70 kg runner works out to 560 to 840 g daily.
That is a lot of food, so make it easy on your gut:
- Swap high-fiber foods (wholegrain bread, beans, big salads) for white rice, noodles, potatoes, bread and bananas.
- Spread carbs across 5 or 6 smaller meals and snacks rather than two giant plates.
- Add carbohydrate drinks to your day if you cannot finish your meals.
- Keep protein and fat modest, and skip anything you have not eaten before a long run.
If you want to go deeper, read our guide to the benefits of carb loading for a marathon.
A simple two-day example
For a 65 kg runner, a daily target in the 8 g/kg range is about 520 g of carbohydrate. That could look like this: a large bowl of white rice porridge with a banana and honey for breakfast, a mid-morning bagel with jam and a carbohydrate drink, a big plate of rice or noodles with lean protein for lunch, an afternoon snack of bread or rice cakes, a pasta or rice dinner, and a light evening snack. Adjust to your body size and appetite, and note that your body weight may go up by a kilo or so as you store glycogen with water. That is normal.
Race morning: breakfast and the hydration timeline
Most Singapore marathons start before sunrise, so your breakfast may come at 2 or 3 a.m. Do not skip it. Sources differ on the exact numbers, so pick a target and rehearse it in training:
- RUN Singapore recommends a light, easily digested breakfast with 1 to 4 g of carbohydrate per kg of body weight.
- Runner’s World reports a target of 2 to 4 g per kg 2 to 4 hours before the race, followed by extra carbs shortly before the start, such as dates or a gel 15 minutes before.
- For a 65 kg runner, 2 g/kg is 130 g of carbohydrate: think two slices of white toast with jam, a banana, and a sports drink.
Choose foods that are low in fiber and fat. If you need ideas for what sits well in your stomach, this list of the best foods to eat before running is a good starting point for your breakfast trials.
Fluid timeline before the start
RUN Singapore suggests this sequence: 5 to 7 ml per kg of body weight four hours before, 400 to 500 ml with breakfast, small sips of water 30 to 60 minutes before, and 300 to 400 ml of sports drink or water plus a gel 15 minutes before. Runner’s World adds that keeping the late volumes small, about 5 to 10 ounces half an hour before, helps you avoid starting with a full bladder.
Fueling during the race: how many grams per hour
The consensus for events longer than an hour in the heat is 30 to 60 g of carbohydrate per hour, and up to 90 g per hour for events over 2.5 hours. RUN Singapore echoes this and notes that experienced athletes with a trained gut may handle up to 90 g per hour, especially with glucose-and-fructose mixes.
A finish-time guide from RunDataLab puts sub-3:30 runners at 60 to 90 g per hour, and slower runners at 30 to 60 g per hour. Use these as starting points, then adjust to what your stomach tolerates.
| Target finish time | Carbs per hour | Example with 25 g gels |
|---|---|---|
| Under 3:30 | 60 to 90 g | 2.5 to 3.5 gels per hour |
| 3:30 to 4:30 | 30 to 60 g | 1.5 to 2.5 gels per hour |
| Over 4:30 | 30 to 60 g | 1.5 to 2.5 gels per hour |
The gel column is our own arithmetic for a 25 g carbohydrate gel. Check the carbohydrate content on your gel’s label and do the sum for your product.
Turning grams into a race-day schedule
- Work out your hourly target from your finish time and training experience.
- Divide by the carbs in each gel, chew or drink serving.
- Space intakes every 20 to 30 minutes. Small, frequent doses are easier on the stomach than one big hit.
- Start early. Runnersconnect suggests starting fueling around mile 4, and a first gel in the first 30 to 45 minutes is a common anchor point.
- Line gels up with aid stations so you can take water with each one. One Singapore guide recommends tearing the gel top open before the station so you can grab water with the same hand.
If you are building a plan around one brand, our Maurten Full Marathon Starter Kit is a ready-made place to start. Read our race day nutrition guide for more ways to organize it.
Fluids and sodium in the heat
Heat consensus guidance says sodium is the main electrolyte lost in sweat, and that during exercise longer than one hour you should aim for a drink containing 0.5 to 0.7 g/L of sodium, rising to 1.5 g/L if you get muscle cramping.
In practical terms:
- Fluids: 400 to 800 ml per hour depending on sweat rate, with most runners able to absorb about 180 to 210 ml every 15 minutes in small, frequent sips. Lean toward the high end in hot weather.
- Sodium: 300 to 600 mg per hour. Many gels carry only 40 to 100 mg, so electrolyte drinks or salt capsules often fill the gap.
- Do not overdrink. Guidance summarized in a Singapore race guide says the aim is to limit weight loss from sweat to about 2% while never drinking more than you sweat. Finishing heavier than you started suggests overdrinking, which can dilute blood sodium and be dangerous. If you feel bloated, sloshing or nauseous, ease off the fluids and see the medical team at the next aid station.
Weigh yourself before and after a long, hot training run to learn your sweat rate. For more on salt, see the role of sodium during marathon running and our electrolyte balance guide. If cramping is a recurring problem, talk to a sports doctor or dietitian about your sodium needs.
Train your gut before race day
Your stomach can be trained, just like your legs. Take your target carbs per hour on long runs, and build up gradually: if you normally take 30 g per hour, move to 45 g, then 60 g, and only then test higher. The heat matters here too: guidance on gut training notes that heat combined with high carbohydrate intake and high intensity can slow stomach emptying, so practice in hot conditions that match race day.
On your long runs, do this:
- Use the same gels, drinks and timing you plan to use in the race.
- Run at the time of day you will race, or at least in similar heat.
- Practice taking gels while running at pace, and drinking from cups.
- Note what upsets you, adjust one thing at a time, and log it.
- Test your clothing and gear at the same time. A tip from the apparel side: testing your gear on training runs saves you from chafing surprises on race day.
For a step-by-step progression, see our gut training tips for marathon runners and how to fuel during training runs.
Our perspective
We see the same pattern every race season in Singapore: runners train for months, then change their fueling on the morning of the race. A new gel, a bigger breakfast, an extra cup of sports drink at every station. The stomach does not forgive surprises, especially in this humidity.
Our advice is simple. Choose your products early, write your hourly plan on paper, and run your long runs exactly as you will run the race. Decide your grams of carbohydrate, your fluids and your sodium, and let the heat teach you what to adjust.
This is why we stock gels, hydration mixes and recovery products from brands athletes already trust, and why we focus on guaranteed authenticity and next-day delivery within Singapore. You should be able to buy what you need in time to test it properly, with weeks to spare, not days. You have put in the miles. Fueling is how you get the most out of them.
Jason John
Pick your products from Racepack
A good plan needs the right tools. At Racepack.sg you can build your marathon kit in one place: energy gels, hydration mixes, vitamins and minerals and more from international brands, and a Garmin smart watch to track your pace and your fueling reminders.
After the race, restock with recovery powders and protein powder to support your recovery. If your plan is still taking shape, our BMI-based fueling guide for Singapore runners and our guide to how Singapore coaches plan race-day fueling will help you set your numbers.
Practical tips for the final week
- Order early. Buy your race gels and drinks at least 3 to 4 weeks out so you can test them on long runs.
- Pack a labeled fueling bag. Divide gels by hour so you do not do math at kilometer 30.
- Write it on your wrist or phone. A simple schedule: minute 30, 55, 80 and so on.
- Carry a backup. One extra gel and a few salt capsules cost almost nothing in weight.
- Keep breakfast boring. Same food, same time as your last two long runs.
- Have a plan for the last 10 km. Fatigue makes eating harder, so pre-open your gels and decide that you will take one at each remaining aid station.
FAQ
How should I fuel for a full marathon?
Carb load for 2 to 3 days, eat a light carb-based breakfast 2 to 4 hours before the start, and take 30 to 60 g of carbohydrate per hour during the race. Trained runners can build toward 90 g per hour. Add fluids and sodium according to your sweat rate.
How many gels do I need for a marathon?
Divide your hourly carb target by the carbs in one gel, then multiply by your expected hours. For a 4-hour finish at 60 g per hour with 25 g gels, that is about 2.4 gels per hour, so roughly 10 gels. Check the label on your own gel, since content varies.
What is the 10-10-10 rule for marathons?
It is a pacing method, not a fueling rule. The runnersconnect version splits the race into the first 10 miles, the second 10 miles and the final 10 km, running conservatively, then at goal pace, then pushing at the end. You still need your own fueling schedule.
Why do some runners drink cola during a marathon?
Cola offers quick sugar and caffeine. However, Runner’s World Italy cautions that it is hypertonic, which may slow fluid absorption, and that carbonation can cause bloating and stomach cramps. If you want to use it, practice in training first, or choose a gel and drink built for racing.
Do I need more carbs because it is hot and humid in Singapore?
No, the carb targets stay the same. Heat does make a full stomach feel worse and raises your fluid and sodium needs. Rehearse the exact plan in warm, humid long runs.
How much sodium do I need during a marathon?
RUN Singapore and RunDataLab both suggest 300 to 600 mg of sodium per hour. Since many gels contain only 40 to 100 mg, you may need an electrolyte drink or salt capsules. Runners with recurring cramps should see a sports doctor or dietitian.
How much water should I drink per hour?
A common range is 400 to 800 ml per hour, adjusted to your sweat rate and the conditions. Sip small amounts often, and never drink more than you sweat. Weigh yourself before and after long runs to learn your own numbers.
What should I eat for breakfast on race morning?
Choose a light, low-fiber, familiar meal such as white toast with jam, a banana and a sports drink, around 2 to 4 hours before the start. Aim for roughly 1 to 4 g of carbohydrate per kg of body weight, depending on the source and what your stomach tolerates.
Where can I buy marathon gels and electrolytes in Singapore?
You can shop energy gels, hydration mixes and a Maurten marathon starter kit at Racepack.sg, with next-day delivery within Singapore. Order early enough to test everything on your long runs.
Ready to fuel your marathon? Buy Now at Racepack.sg and get your race-day kit sorted.
Sources
- Consensus recommendations on training and competing in the heat
- Fuel Smart, Run Strong, RUN Singapore
- Singapore Marathon fueling guide: heat, water, gels
- What To Eat Before a Marathon, Cleveland Clinic
- How to Fuel a Race, Runner’s World
- Race-morning eating and drinking, Runner’s World
- Marathon Pacing Strategy: The 10-10-10 Method
- Perché gli atleti bevono Coca-Cola in gara?, Runner’s World Italia
