Running a 4-hour marathon means you’re pushing your body for 26.2 miles at a steady, demanding pace. You’ve trained hard. You’ve nailed your long runs. But if you skip fueling right, you’ll hit the wall hard-around mile 20-and your race could fall apart. So how many gels should you actually take? The answer isn’t just "take one every 45 minutes." It’s about your body’s limits, your pace, and what your stomach can handle.
Why Gels Matter in a 4-Hour Marathon
At a 4-hour pace, you’re running about 9 minutes per mile. That’s fast enough that your body burns through glycogen-your stored carbs-faster than you can replace it naturally. After 90 minutes, your liver glycogen starts to drop. By mile 18, you’re running on empty if you haven’t refueled. Energy gels give you a quick, concentrated hit of glucose and fructose to keep your muscles working. Skipping them isn’t bravery. It’s a mistake.
Most runners burn 60-90 grams of carbs per hour during a marathon. A standard gel has 20-30 grams of carbs. That means you need at least two gels per hour to keep up. But here’s the catch: your gut can only absorb so much. Too many gels too fast? You’ll get stomach cramps, nausea, or worse. The sweet spot is balance.
The 3-Gel Rule for a 4-Hour Marathon
For most runners finishing in 4 hours, three gels is the gold standard. Take your first gel at mile 5-6, your second at mile 12-13, and your third at mile 19-20. That gives you a steady drip of carbs without overwhelming your system.
Why not four? Because by mile 20, you’re already in the danger zone. If you take a fourth gel at mile 22, you’re risking GI distress when your body is under maximum stress. Plus, you’ll likely be drinking water or sports drink at every aid station. Many of those drinks already contain carbs. Adding a fourth gel on top could push you past 90g/hour-your gut’s practical limit.
Here’s a simple timeline:
- Mile 5-6: First gel (early, before you start burning low)
- Mile 12-13: Second gel (mid-race, when fatigue creeps in)
- Mile 19-20: Third gel (just before the wall hits)
This timing keeps your blood sugar stable and delays fatigue. It’s not magic-it’s science. A 2023 study in the Journal of the International Society of Sports Nutrition tracked 1,200 marathoners and found those who took three gels at these intervals finished 8-12 minutes faster on average than those who took one or two.
What About Sports Drinks?
Don’t forget: you’re not just eating gels. You’re drinking sports drinks at every aid station. Most sports drinks have 14-19 grams of carbs per 8 oz. If you’re drinking 16 oz every 3-4 miles (that’s 4-5 bottles over the race), you’re getting another 30-40 grams of carbs from fluids alone.
So if you’re drinking sports drink at every station and taking three gels, you’re hitting 80-100 grams of carbs per hour. That’s at the top end of what your body can absorb. If you’re not used to this, you’ll get sick. Practice this combo in training. Do a 16-mile run with the same gel-and-drink plan you’ll use on race day. See how your stomach reacts.
What If You’re Slower or Faster?
Not everyone runs a 4-hour marathon. Some hit 4:30. Others finish in 3:30. Your pace changes your fuel needs.
- Under 3:45: You’re burning carbs faster. Consider four gels, but space them out: mile 5, 11, 17, 23. Skip the fourth if you’re drinking high-carb sports drinks.
- 4:00-4:30: Stick with three gels. You’re still moving fast enough to need carbs, but your body is under less stress. Don’t overdo it.
- Over 4:30: You can get away with two gels-mile 6 and mile 18. But make sure you’re getting carbs from other sources: bananas at aid stations, sports drink, even pretzels. Slower runners still need fuel, just less aggressively.
Which Gel Should You Use?
Not all gels are the same. Some are thick, some are runny. Some have caffeine, some don’t. Some have added electrolytes. Your best bet? Pick one that’s worked for you in training.
Look for gels with:
- 20-30g of carbs total
- A 2:1 glucose-to-fructose ratio (this helps your gut absorb more carbs without cramps)
- No extra caffeine unless you’re used to it
- No artificial sweeteners like sucralose (they upset stomachs)
Popular options that meet this: Maurten Gel 100, GU Energy Gel, SiS GO Gels, and Honey Stinger. Avoid gels with more than 30g of carbs or those with added protein or fat-they slow absorption and can cause nausea.
What If You Feel Sick?
It happens. You take a gel, and your stomach rebels. Don’t panic. Stop eating for 15-20 minutes. Sip water slowly. Walk for a few hundred meters if you can. Your body doesn’t need carbs every 20 minutes-it needs them every 45-60. If you miss one gel, you can catch up with the next one.
Never force a gel down if you’re queasy. Your goal isn’t to finish with every gel consumed. It’s to finish without vomiting or collapsing. A runner who took two gels and stayed upright will always beat one who took five and stopped at mile 22.
Practice Before Race Day
You wouldn’t run a marathon in new shoes. Don’t run it with new fuel. Test your gel plan during your longest training runs. Do a 18-mile run with the same gels, same timing, same sports drink. Track how you feel at mile 12, mile 16, and mile 18. Did your stomach stay calm? Did you feel strong? Did you need to stop?
If you didn’t test it, you’re gambling. Race day isn’t the time to experiment. Your body remembers what it’s trained for. If you’ve never taken a gel before mile 10, don’t start on race day.
Final Tip: Hydration Is Part of Fueling
Gels need water to work. Swallowing a gel dry is like trying to dissolve sugar in your mouth-it sticks, it burns, it causes cramps. Always take your gel with 4-6 oz of water. If you’re at an aid station, grab water even if you don’t feel thirsty. Dehydration slows carb absorption. You’ll feel worse faster.
And don’t chug. Sip. Slow and steady wins the race-even when it comes to your water bottle.
What About Energy Chews or Real Food?
Some runners prefer chews, dates, or even pretzels. That’s fine. But track your carb intake the same way. Two chews = one gel. One banana = two gels. Real food is great, but it’s harder to measure. Gels are precise. For a 4-hour marathon, precision matters.
If you use real food, make sure it’s low-fiber and low-fat. No nuts, no peanut butter, no granola bars. Stick to simple carbs. Your gut doesn’t want to digest anything complex when you’re running hard.
Bottom Line
For a 4-hour marathon, take three gels-at miles 5-6, 12-13, and 19-20. Pair them with sports drink at every aid station. Drink water with each gel. Practice this in training. Don’t overdo it. Don’t skip it. Fueling isn’t optional. It’s the difference between hitting the wall and finishing strong.
It’s not about how many gels you can stuff in. It’s about how many your body can use without breaking down. Three is enough. And if you get it right, you’ll cross that finish line with your legs still working.
Can I skip gels and just drink sports drink?
You can, but you won’t get enough carbs. Most sports drinks have 14-19g of carbs per 8 oz. To hit the 60-90g/hour your body needs, you’d have to drink 3-5 bottles per hour. That’s too much fluid for most runners and can cause hyponatremia. Gels give you concentrated carbs without the volume. They’re the most efficient way to fuel.
Should I take a gel before the race starts?
No. Your body already has enough glycogen stored from your pre-race meal. Taking a gel before the start can spike your blood sugar and cause a crash before mile 5. Save your first gel for when you’ve been running for 45-60 minutes.
What if I forget a gel at mile 12?
Don’t panic. Take your next gel at mile 19-20 instead. You’ll be a little low on carbs for 30-45 minutes, but your body can handle it. Most runners don’t hit the wall until after mile 18. You’ll still have enough stored glycogen to make it to your next gel. Just don’t wait until mile 22-that’s too late.
Do I need caffeine in my gels?
Only if you’ve trained with it. Caffeine can help in the second half of a marathon by reducing perceived effort and boosting focus. But if you’ve never used it before, don’t start on race day. It can cause jitters, nausea, or even heart palpitations under stress. Stick to non-caffeinated gels unless you’re certain they agree with you.
Can I use honey packets instead of gels?
Yes, but be careful. Honey is pure sugar, so it works. But it’s sticky, harder to carry, and doesn’t come with electrolytes. A single 1 oz honey packet has about 17g of carbs-close to half a gel. You’d need two per hour. Also, honey can crystallize in cold weather. Gels are designed for runners. Honey is a backup, not a replacement.
