The long training run is the cornerstone of distance running.
It’s where endurance is built. It’s where mental toughness grows. And whether you’re logging miles outside or putting in focused time on your treadmill at home, your fueling strategy can make or break the session.
If you’re investing in your training, especially with quality indoor fitness equipment, you want every mile to count. That starts with developing a fueling plan that works specifically for your body.
There are general guidelines for what to eat before, during, and after a long run. But the real secret is one size does not fit all. Start tracking more than just your minutes and miles. Practice during your weekly long runs, even the ones you do indoors when weather or schedule makes treadmill training the smarter choice.
What works for your training partner may not work for you. Tracking now will shine light on what works and what doesn’t. By race weekend, or your next PR attempt on your treadmill, you’ll know exactly what your body needs.
Pre-Run Fueling for Stronger Miles
Before a long run you want to ‘top off’ muscle glycogen. Glycogen is how carbohydrates are stored in your muscles. Think of it like a backup fuel tank. When your muscles need immediate energy, glycogen releases glucose into the blood. As a distance runner, you are aiming for a consistent and steady pace. And no matter if your training is outdoors or inside on a more controlled treadmill workout, you will want to maximize how much glycogen is ready and waiting.
General guideline:
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200–300 calories of easily digestible carbohydrates
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8–12 ounces of fluid about an hour before starting
If you’re eating solid food (like toast with nut butter and a banana), aim for 1–2 hours before your run. Why? These nutrients are tied up with others, and your body needs to work a little longer to break them apart.
If you’re jumping on your treadmill early in the morning, lighter options work well:
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A banana
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A smoothie
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A sports drink
One of my favorites before a steady indoor run? A banana with a teaspoon of almond butter about 90 minutes before starting. Or a simple smoothie with almond milk, berries, and half a banana.
What does research say?
A 2021 study found that consuming carbohydrates before endurance exercise significantly improved time-to-exhaustion performance compared to starting fasted. In other words, runners lasted longer when they fueled beforehand. Findings also say pre-exercise carbs reduce perceived effort during longer exercise times.
That matters, especially during controlled treadmill sessions where pacing is steady and there’s no natural downhill break. Fueling beforehand can literally make the workout feel easier at the same speed.
Fueling During Long Runs (Yes, Even Indoors)
Once your run goes past 60 minutes, whether outdoors or on your treadmill, your glycogen stores start to drop.
The American College of Sports Medicine recommends:
30–60 grams of carbohydrate per hour for endurance sessions lasting longer than one hour.
For runs 60–120 minutes:
Keep it simple. Sports drinks or gels with water provide easy-to-digest sugars. Both will effectively deliver quick acting glucose. If you’d rather aim for a whole-food option, you should consider naturally dried fruits. Raisins have been shown to be just as effective as sports jellybeans at maintaining performance late in the game.
For runs longer than 2.5 hours:
Use a combination:
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Sports drink
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Gels
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Low-fat, low-fiber solid foods
Just avoid stacking everything at once. Spacing fuel every 10–20 minutes works well. Many runners set a timer, which is incredibly easy to do during indoor training sessions.
If stomach issues pop up, it’s usually:
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Too much fuel
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Too fast
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Or the wrong type for your system
This is why practicing during training is so valuable.
Post-Run Fueling: Recover Strong, Train Again Sooner
When your long run ends, indoors or outside, recovery begins. The ’30-minute window’ has been a very common recommendation. Eating within 30 minutes is great but new findings suggest that window is not so narrow. If a runner eats a balanced meal before a long run, the urgency for immediate post-run nutrition is reduced because glycogen stores are not completely depleted. However, for those long runs we’ve been talking about (the ones that are more than 2 hours), rapid refueling is still important.
That window for muscle repair stays open as this study suggests for 24-48 hours, but if you are planning to run again tomorrow, well you do need to refuel quickly.
Within 30 minutes:
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Eat 300–400 calories
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Aim for a 4:1 carbohydrate-to-protein ratio
Carbohydrates replenish glycogen. Protein supports muscle repair.
Options:
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Turkey sandwich + pretzels
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Veggie omelet + toast
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Smoothie with protein powder, banana, and berries
Indoor runners often finish workouts at home, which makes recovery nutrition even easier to execute consistently. No drive home. No delay. Just refuel and start recovery right away.
Continue eating balanced meals throughout the day and sip fluids to rehydrate fully.
Does Fueling Change for Indoor Runs vs. Outdoor Runs?
Treadmill running often means:
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Controlled pacing
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Longer steady-state efforts
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Structured endurance sessions
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Fewer natural terrain breaks
That consistency increases the importance of starting fueled and staying fueled.
The better you fuel:
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The stronger your late miles feel
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The more consistent your pace becomes
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The better you recover
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The more value you get from every training session
Fueling for distance running isn’t just about avoiding the wall. It’s about maximizing your performance, whether you’re chasing a PR outdoors or building endurance on your treadmill at home.
And the best time to perfect your fueling strategy?
Your very next long run.
