Don’t Let Common Running Mistakes Sabotage Your Long Runs

You are putting in the work. You are waking up early. You are logging the miles. But you might still fail.

Whether you are training for your first half marathon or you are a seasoned marathoner trying to qualify for Boston, the long run is the single most important lever you can pull. It builds the engine. It builds the mind.

But here is the hard truth: Most people do it wrong.

They make common running mistakes that destroy their progress. They think working harder is the answer. It usually isn’t. Working smarter is.

If you are inadvertently sabotaging your long runs, you are wasting time. And time is the one thing you can’t get back.

In this article, I’m going to break down exactly how to fix your long-distance training. We are going to talk about fuel, the right training plan, and the specific common long run traps that catch everyone.

Read this. Fix your runs. Crush race day.

Key Takeaways

• Pace: Slow down. Seriously.
• Food: Eat carbohydrates while you run. Don’t bonk.
• Drink: Salt and water. Early and often.
• Miles: Add 10% a week max. Don’t be greedy.
• Gear: Test it now. Not on race day.
• Warm-up: 5 minutes helps blood flow and prevents tears.
• Recovery: Eat post-run. Sleep more.
• Terrain: Train for the course you are running.
• Listen: Sharp pain means stop. Ache means go.
• Head: Keep it fun to avoid burnout.
• Do the work. Avoid the mistakes. Make your long runs count.

Overview: the long run as a training product

Think of the long run as a piece of kit you put time into each week. Its core specifications are simple:

• Duration: Typically 75 minutes to 4+ hours depending on goal.
• Pacing: Mostly easy conversational running, with optional pace blocks or fast finishes.
• Fuel and hydration: Regular carbohydrate intake and fluids for anything over 60 minutes.
• Kit: Shoes, clothing, and any carry systems for nutrition and fluids.
• Recovery: Cooldown, refuel, and proactive recovery strategies after the run.

Approach this session like a product you want to test and refine. The better you tune these specifications, the more reliable the output on race day.

Why is Pacing the Most Common Mistake in Long Runs?

The biggest common mistake is ego.

Mistakes runners make almost always start with running too fast. You feel good at mile one. You want to prove you are fast. You try to hit your marathon pace in practice.

Stop it.

The goal of a long run is not speed. The goal is duration. You are trying to build endurance. You are teaching your body to burn fat instead of sugar.

When you run fast, you burn glycogen. When you burn glycogen, you crash. It’s biology.

Many runners think “slow” means “weak.” A running coach will tell you the opposite. Slow means aerobic. Aerobic means you can run forever. If you run your long days hard, you are too tired for your speed days. You enter a “grey zone” of training where you are too tired to get fast and too fast to recover.

Pacing Guidelines for Long Runs

To avoid common pacing errors, stop looking at the pace on your watch. Look at your heart rate. Or just talk to yourself. If you are gasping, slow down. By slowing down, you reduce the risk of injury and you actually finish the run.

If you want to know exactly how to dial this in, read our guide on running pace training.

Are You Sabotaging Your Long Runs by Ignoring Nutrition?

You wouldn’t drive a car across the country on an empty tank. So why do you try to run 20 miles on a cup of coffee?

Running for 90+ minutes requires fuel. This isn’t optional. Your body has limited glycogen stores. When they run out, you stop. You hit ‘the wall’.[1] Your legs stop working. You hate your life.

To power you through the long miles, you need to consume calories. You need to eat while you run.[1][2]

Long Run Fueling Strategy

Take a gel. Eat some chews. Drink a sports drink. These give you carbohydrate which is immediate energy. This helps maintain performance.

If you skip this, your body starts eating its own muscle for energy. You lose muscle. You get weaker.

Also, the day before a long run counts. Eat a high-carb dinner. Don’t eat a salad with 50g of fiber unless you want to spend your run in a porta-potty. Use healthy fats and carbs to keep your energy levels high.

Get the specifics on what to eat in our article on long run nutrition.

How Does Poor Hydration Impact Your Marathon Training?

Hydration is simple, but people mess it up.

If you are dehydrated, your blood volume drops. Your heart has to beat faster to move less blood. Your body temperature goes up.[3][4][5] Your performance declines.

You have to hydrate early and often.

Don’t chug a gallon of water 5 minutes before you start. That just makes you slosh. Drink consistently all week. During the run, drink before you are thirsty. If you are thirsty, you are already behind.

Hydration Signs to Watch For

• Urine Color: Lemonade is good. Apple juice is bad.
• Thirst: A lagging indicator. Don’t rely on it.
• Skin: Pinch it. If it stays up, drink water.[2][6]
• Salt: White lines on your hat? You are a salty sweater. You need electrolytes.[6]

You lose salt when you sweat. If you only drink water, you dilute your blood sodium. This leads to cramping.

Use an electrolyte mix. It keeps your muscles firing.[7] This is crucial in hot weather conditions.

Check out our full breakdown on hydration strategies for distance runners.

Are You Increasing Mileage Too Fast and Risking Injury?

More is not better. Better is better.

The easiest way to fail is to get injured. The easiest way to get injured is to ramp up mileage too fast.

If you add more than 10% to your weekly volume, your injury risk skyrockets. Your lungs adapt faster than your tendons. You will feel fit, but your bones will be weak.

A solid training plan has “step-back” weeks. You lower the overall mileage to let your body heal. This is where the gains happen. Recovery is when you get stronger.

Safe Mileage Progression Example

Gradually increasing volume takes patience. It is hard to stick to your planned miles when you feel good. But the marathon is no easy feat.

If you want a blueprint, look at our half marathon training guide.

Why Should You Never Try New Gear on a Long Run?

Race day is for execution. Training is for testing.[8]

Never, ever wear new stuff on a 20-mile run. That is a rookie move. This is a common long run mistake that ends in blood.

If you wear new shoes, you might get a blister. If you wear new shorts, you might chafe until you bleed.

Experienced runners have a rule: Nothing New On Race Day.

Essential Gear Checklist

• Shoes: Break them in. 50 miles minimum.
• Socks: No cotton. Ever. Synthetic or wool.
• Apparel: Test it. Does it ride up? Does it rub?
• Anti-Chafe: Lube up. Everywhere.
• Hydration Pack: Make sure it doesn’t bounce.

Test your gear now. If it hurts at mile 6, change it. Don’t wait until mile 18.

If you need gear advice, we have a list of essential outdoor running gear. This will help you avoid pain.

Are You Skipping the Warm-Up Before Starting Your Long Run?

You aren’t a machine. You can’t just turn the key and go 60mph.

Starting your long run cold is asking to snap something. Cold muscles are stiff. Stiff muscles tear.

Skipping the warm-up is a missed opportunity for injury prevention.

Do 5 minutes of dynamic work. That’s it. Leg swings.[3][4][5][7] Lunges. Get the blood flow moving.

Effective Dynamic Warm-Up Routine

1. Leg Swings: Open up the hips.
2. Walking Lunges: Wake up the glutes.[7]
3. Calf Raises: Prep the Achilles.
4. High Knees: Get the heart pumping.
5. Torso Twists: Loosen the back.

This addresses weak muscles that have been asleep all night. It makes the first mile feel easy instead of terrible.

Need more moves? Check out runners strength exercises.

Is a Lack of Post-Run Recovery Hurting Your Progress?

The workout isn’t done when you stop running. It’s done when you eat.

If you finish a run and don’t eat, you are sabotaging your long runs. The 60 minutes post-run is the magic window.

You need to consume protein and carbs. Immediately.

This starts the restorative process. It stops muscle breakdown. It refills the tank.

Post-Run Recovery Priority List

1. Hydrate: Water + Salt. Now.
2. Refuel: Food within 45 mins.
3. Stretch: Keep the muscles loose.
4. Rest: Sleep is the ultimate steroid.

Quality sleep is non-negotiable. If you don’t sleep, you don’t grow.

Read our nutrition tips for post-workout recovery to get this right.

How Does Terrain Choice Affect Your Long-Distance Training?

If you train on a pancake flat road, hills will kill you on race day.

Ignoring terrain is a common running mistake. Specificity matters.

If your marathon is hilly, run hills. If it’s on concrete, run on concrete.

Terrain Comparison Table

Mix in cross-training activities. But remember, you have to prepare your legs for the specific pounding of the race.

Also, check the weather conditions. Don’t be a fair-weather runner if your race is in July.

Learn more about the impact of running surfaces and injury risk.

Are You Ignoring Your Body’s Signals During Longer Runs?

Pain is data.

Marathon runners love to suffer. But there is a difference between suffering and breaking.

Runners make the mistake of pushing through “bad pain.”

Fatigue vs. Injury: How to Tell the Difference

If your perceived effort is sky high at a slow pace, you might be sick. Or overtrained.

Adjust your plan based on individual needs. It takes courage to stop. It takes stupidity to keep going until you break.

If you are already hurt, read how to recover from a running injury.

How Can You Avoid Common Pitfalls and Prevent Burnout?

Burnout kills more running careers than injury.

If marathon training becomes a job you hate, you will quit.

Don’t obsess over the data. Sometimes, leave the watch at home. Run with friends.

Keep your training schedule flexible. Use cross-training activities to get a mental break.

Performance on race day comes from consistency over months, not one heroic run. Everyone makes long run mistakes. Learn from them. Move on.

Check out our guide on running mental training to keep your head in the game.

References and Further Reading

• Mayo Clinic: Runners: How to stay hydrated
• Runner’s World: The 10 Golden Rules of Injury Prevention
• ACE Fitness: The Benefits of Dynamic Stretching
• Harvard Health: Running for health
• TrainingPeaks: The Science of Long Runs

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Lead Data Scientist

Alexios Papaioannou

Mission: To strip away marketing hype through engineering-grade stress testing. Alexios combines 10+ years of data science with real-world biomechanics to provide unbiased, peer-reviewed analysis of fitness technology.

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Latest Data Audit December 2, 2025