When Should You Start Fueling During a Run?

Proper fueling can make or break your performance during long runs, races, and workouts. Whether you’re training for a marathon or tackling a challenging interval session, your body relies on carbohydrates as its primary energy source. Without adequate fueling, you risk running out of energy, hitting the dreaded "wall," and slowing your recovery.

When Should You Start Fueling?

As a general rule, start fueling during runs that last 90 minutes or longer. This includes:

• Long runs
• Speed workouts
• Tempo sessions
• Any high-intensity workouts exceeding 75-90 minutes

Why? The demand for carbohydrates increases with both duration and intensity.‍

Fueling during these efforts helps maintain energy levels, delay fatigue, and improve performance.

What Should You Be Fueling With?

Energy Gels

• Popular among runners due to their convenience and ease of use.
• Contain ~30g of carbs per gel, making it easy to meet fueling targets.
• Brands like Huma, GU, NeverSecond, and Untapped are great options.

Chews and Waffles

• Offer variety and a solid option if gels don’t agree with your stomach.
• Chewing takes more effort, so use them on easier sections of your run.

Liquid Carbohydrates

• Combines hydration and fueling.
• Ideal for runners who struggle with gels or prefer sipping calories.

Other Options

• Energy bars, dried fruit, or small snacks can work for long, steady efforts.
• Experiment during training to find what works best for you.

How Much Should You Be Taking In?

The recommended intake is 60-90g of carbohydrates per hour for optimal performance. This translates to:

• 1 gel (30g) every 30 minutes.
• Or a mix of gels, chews, and liquids to reach your target.

If 60g feels like too much initially, start with 30-45g/hour and gradually increase. Training your stomach is just as important as training your legs.

Common Fueling Challenges

GI Distress

• If gels upset your stomach, space them out or opt for chews/liquids.
• Practice fueling during training to help your stomach adapt.

Fatigue from Repetition

• Switch between flavors and types of fuel to avoid "flavor fatigue."
• Keep multiple options on hand for variety.

Fueling During Long Runs vs. Races

• During long runs: Use them as practice for race day. Test different products, timings, and quantities.
• During races: Stick with a plan you’ve practiced during training to avoid surprises.

Do I Have to Use Gels?

No, but they’re often the most efficient option. Gels:

• Don’t require chewing, saving time and energy.
• Are easy to carry in belts or packs.

Other options, like bars or snacks, work well but might slow you down during races. Elite marathoners often rely on liquid carbohydrates, but most recreational runners find it easier to use gels or a combination of products.

The Role of Hydration in Fueling

Fueling isn’t just about carbs, it’s also about fluids and electrolytes. Here’s how to stay hydrated:

• Drink 400-600ml of water per hour during runs, depending on the weather and intensity.
• Add electrolytes to your water to improve absorption and prevent hyponatremia (low sodium levels).
• If racing, take advantage of aid stations for hydration.

Why Practice Fueling During Training?

1. Boosts Performance

• Studies show that carb-fueled runs improve endurance and speed compared to running without fuel.

2. Prepares Your Stomach

• Your digestive system can be trained to handle fuel while running.
• Regular practice reduces the risk of GI issues on race day.

3. Enhances Recovery

• Fueling mid-run replenishes glycogen stores, allowing for faster recovery post-run.

4. Builds Fueling Skills

• Practice the mechanics: pulling out gels, opening them while running, and managing wrappers.

Why Fueling Is Non-Negotiable

You might be able to run long distances without fueling, but it comes with consequences:

1. Performance suffers: You’ll hit the wall sooner, limiting your potential.
2. Recovery slows down: Running without fuel stresses your body more, making recovery harder.
3. Poor race-day preparation: If you don’t practice fueling in training, you’re less likely to handle it well during a race.

How to Track Your Fueling

Keeping a fueling log can help you optimize your strategy. Write down:

• The products you used (gels, chews, drinks).
• The timing (how often you fueled).
• How your stomach felt during the run.

Over time, you’ll identify what works best and fine-tune your plan for race day.

Final Thoughts

Fueling during runs may feel like "one more thing to think about" but it’s essential for optimal performance, recovery, and overall enjoyment.

Start experimenting during your training runs to find what works for you.

Whether it’s gels, chews, or liquids, the key is consistency and preparation. With a well-practiced fueling strategy, you’ll be ready to tackle long runs and races with energy to spare.