How much caffeine is safe from energy gels during a race?

Most runners tolerate 100–300 mg of total caffeine during a race, depending on body size and sensitivity. If you use caffeinated gels, check the label and track your total from coffee, soda, and other products so you do not exceed your usual daily intake on race day.

Athletic Annex running store interior with text overlay promoting energy gels to fuel races without stomach issues or crashes

During the Race: Best Energy Gels for Every Runner

Q: How often should I take energy gels during a race?

Most runners should take an energy gel every 30–40 minutes during a race. Start your first gel around mile 4–5, then continue at regular intervals, and always practice this schedule in training before race day.

Q: Should I take energy gels with water?

Yes. Energy gels should always be taken with water to help absorption and reduce the risk of stomach upset. Avoid washing gels down with sports drinks, as the combined concentration of carbs can be too high for your gut.

Q: Which energy gels are best for sensitive stomachs?

Gels with simpler formulas and smoother textures tend to work best for sensitive stomachs. Many runners do well with options like Maurten Gel 100, which uses hydrogel technology designed to be gentle on the gut when taken with water.

Q: Should I try new energy gels on race day?

No. You should never try a new gel for the first time on race day. Test your gels, timing, and hydration strategy on long runs and workouts so you know how your stomach responds before you pin on a bib.

Dr. Blake Dircksen PT, DPT, CSCS

September 30, 2025

During the Race: Best Energy Gels for Every Runner

Quick Answer: Most runners should take an energy gel every 30–40 minutes, starting around mile 4–5, and always with water. Maurten Gel 100 is best for sensitive stomachs, GU Roctane works well for long endurance efforts, and NeverSecond C30 is ideal when you need more carbs per gel. Below is a comparison table to help you choose the right gel for your race.

The wrong gel can ruin your race. The right one can power you through the final miles. Here’s how to pick the best gel for your race-day stomach and strategy.

Why Energy Gels Matter

As you push through the miles of a half marathon or full marathon, your body depletes its glycogen stores. Energy gels are a convenient way to replenish these stores, providing a quick source of carbohydrates. Unlike real food, gels are easy to carry and digest, making them ideal for mid-race fueling. Whether you’re tackling the Indianapolis Mini Marathon or a local 5K, energy gels can be crucial for maintaining your energy levels.

How to Use Energy Gels

Timing: Consume a gel every 30–40 minutes during your race.
Hydration: Always wash down gels with water to aid absorption and prevent stomach issues.
Practice: Use gels during training runs to see how your body reacts.
Caffeine: Be mindful of your caffeine intake, especially if you’re sensitive.

Top Picks at a Glance

Best Overall: Maurten Gel 100
Best for Sensitive Stomachs: Maurten Gel 100
Best for Long Races (Marathon+): GU Roctane Energy Gel
Best High-Carb Option: NeverSecond C30 Energy Gel
Best Natural Option: UnTapped Maple Gel

Energy Gel Comparison Table

Energy Gel Comparison — Carbs, Caffeine & Features
Product	Carbs	Caffeine	Key Feature	Best For
Maurten Gel 100	25g	None	Hydrogel digestion	Sensitive stomachs
Maurten Gel 100 CAF	25g	100mg	Caffeine boost	Caffeine users
GU Original Energy Gel	22g	Varies	Variety of flavors	Budget-friendly
GU Roctane Energy Gel	22g	Varies	Electrolytes & amino acids	Endurance athletes
NeverSecond C30 Energy Gel	30g	None	Smooth texture	Extra carbs
UnTapped Energy Gel	26g	None	Natural maple syrup	Natural preference