How to Avoid Hitting the Wall During a Marathon
By Haleigh Hockenberry ยท

Few experiences in running are as dreaded as "hitting the wall." One moment you're cruising along at your planned marathon pace, and the next your legs feel heavy, your energy disappears, and every mile becomes a struggle.
Hitting the wall is one of the most common challenges marathon runners face, especially first-timers. The good news is that with proper training, fueling, and pacing, you can dramatically reduce your chances of experiencing it.
What Does "Hitting the Wall" Mean?
Hitting the wall typically occurs when your body's glycogen stores become depleted. Glycogen is the stored form of carbohydrates that fuels moderate to high-intensity exercise.
During a marathon, your body relies heavily on glycogen for energy. Once those stores run low, your body must depend more on fat for fuel. While fat provides plenty of energy, it is slower to convert into usable fuel, causing a sudden drop in pace and performance.
Many runners experience this around miles 18 to 22, though it can happen earlier if pacing or nutrition mistakes are made.
Build Endurance Through Long Runs
One of the best ways to avoid hitting the wall is to prepare your body through consistent long-run training.
Long runs teach your body to:
- Store glycogen more efficiently
- Improve fat utilization
- Develop muscular endurance
- Build mental resilience
Many marathon plans include several long runs of 16 to 20 miles to help simulate race-day fatigue. These workouts are critical for preparing both physically and mentally for the demands of 26.2 miles.
Don't Start Too Fast
Perhaps the biggest mistake marathon runners make is going out too quickly.
The excitement of race day can make your goal pace feel effortless during the first few miles. However, running even slightly faster than planned early in the race can dramatically increase energy expenditure and accelerate glycogen depletion.
A smart marathon strategy is to start conservatively and settle into your target pace gradually. Many successful runners run the second half of the race at the same pace or slightly faster than the first half.
Practice Your Fueling Strategy
Fueling isn't just for race day. It should be practiced throughout your training cycle.
Most marathon runners consume carbohydrates during the race through:
- Energy gels
- Chews
- Sports drinks
- Other easily digestible fuel sources
A common guideline is to begin fueling early rather than waiting until you feel tired. Once energy levels drop significantly, it's often difficult to recover fully.
Long training runs are the perfect opportunity to test products and determine what works best for your stomach.
Stay Hydrated
Dehydration can make marathon fatigue arrive much sooner.
While hydration needs vary based on weather, sweat rate, and pace, runners should have a plan for replacing fluids throughout the race.
Electrolytes can also play an important role, especially during warmer conditions or for runners who sweat heavily.
Proper hydration supports performance and helps your body use fuel more efficiently.
Carb Load Before the Race
Many runners increase carbohydrate intake in the days leading up to a marathon. This process, known as carb loading, helps maximize glycogen stores before race day.
Foods such as:
- Rice
- Pasta
- Potatoes
- Bread
- Oatmeal
- Fruit
can help increase available energy reserves for the race.
The goal is not overeating but increasing the proportion of carbohydrates in your diet during the final few days before the event.
Train Your Mind Too
The marathon is as much a mental challenge as a physical one.
Breaking the race into smaller segments can help you stay focused. Instead of thinking about all 26.2 miles, concentrate on reaching the next aid station, the next mile marker, or the next fueling point.
Mental preparation can make difficult moments feel much more manageable. In addition to mental strategies, proper nutrition plays a major role in staying strong throughout a marathon. Runner's World's guide to avoiding the marathon wall explains that practicing your fueling strategy during training helps maintain energy levels and reduces the likelihood of hitting the wall late in the race.
The Bottom Line
Avoiding the wall starts long before race day. Consistent long runs, smart pacing, proper hydration, and a well-practiced fueling strategy all work together to keep your energy levels steady throughout the marathon. Runner's World's guide to marathon nutrition also emphasizes that training your gut to tolerate carbohydrates during long runs is just as important as building endurance, helping runners fuel efficiently on race day and maintain performance over longer distances.
While every marathon becomes challenging in the later miles, runners who prepare properly are far more likely to finish strong rather than struggle through the final stretch. With the right training and race-day plan, you can give yourself the best possible chance of reaching the finish line feeling strong and accomplished. The Mayo Clinic also notes that exercising at an appropriate intensity and learning to manage your effort throughout endurance events can improve performance while reducing unnecessary fatigue, making smart pacing another key component of marathon success.