Marathon training is an incredible experience. It pushes your limits, builds endurance, and challenges you in ways you never thought possible. But if you’re not careful, all those miles can start chipping away at the muscle you’ve worked hard to build.
Endurance running naturally puts more stress on your cardiovascular system than your muscles, and without the right approach, you might start feeling weaker rather than stronger as training progresses. The good news? You don’t have to lose muscle just because you're logging long runs. With a few intentional strategies, you can maintain strength, stay resilient, and cross the finish line feeling powerful.
Strength Training: The Non-Negotiable
One of the biggest mistakes runners make is ditching strength training once they start ramping up mileage. I get it. Long runs take time and energy, and it’s easy to think lifting will just add to the fatigue. But strength training is what keeps you running strong. It helps prevent injuries, supports better running mechanics, and ensures you’re not burning through muscle as you increase endurance.
You don’t need to spend hours in the gym. Two to three sessions a week focusing on compound movements like squats, lunges, deadlifts, and push-ups will go a long way. Think of it as maintaining the foundation that allows you to train at a high level without breaking down.
Fueling for Performance and Muscle Maintenance
Many runners under-eat without realizing it, especially during marathon training. When you’re running more, your body needs more fuel—not just to power your workouts but also to maintain muscle.
Protein is key here. Aim for at least 0.7-1 gram per pound of body weight daily. That might look like eggs at breakfast, a protein-rich snack post-run, and lean meats, fish, or plant-based proteins at meals.
Carbs are equally important. They’re your primary fuel source for running, but they also play a role in muscle preservation. If your body doesn’t get enough carbohydrates, it starts breaking down muscle for energy. Prioritize whole food sources like potatoes, rice, oats, fruit, and vegetables.
And don’t forget healthy fats. Avocados, nuts, seeds, and olive oil help with hormone balance, recovery, and overall energy levels.
Hydration: More Than Just Water
Dehydration can lead to muscle cramps, fatigue, and even performance declines. When you’re training for a marathon, you lose more than just water through sweat—you’re also losing electrolytes like sodium, potassium, and magnesium. Replenishing those is key for keeping your muscles functioning properly.
Make sure you’re drinking enough throughout the day, not just during your runs. If you’re sweating a lot, consider adding electrolyte tablets or a sports drink to your routine.
Sleep: Where the Magic Happens
Sleep is one of the most underrated recovery tools for runners. It’s when your body repairs damaged muscle tissue, processes training adaptations, and restores energy levels.
If you’re consistently getting less than seven hours of sleep, you’re not recovering as well as you could be. Aim for 7-9 hours and pay attention to your sleep quality. A solid nighttime routine—like turning off screens an hour before bed and keeping a consistent schedule—can make a big difference.
Recovery and Listening to Your Body
You can do everything “right,” but if you’re ignoring signs of overtraining, it’s going to catch up with you. Soreness is normal. Persistent fatigue, nagging injuries, or a drop in performance? Those are signs you need to adjust.
Incorporating cross-training like cycling, swimming, or even yoga can help keep your muscles engaged without adding extra pounding on your legs. Rest days aren’t a sign of weakness; they’re part of the process.
Want a Plan That Works for You?
Every runner is different. What works for one person might not be right for you, especially if you’re navigating marathon training while also balancing strength goals.
If you want a structured approach that helps you maintain muscle, stay injury-free, and reach your full potential on race day, I can help. As a certified running and strength coach, I design training plans that fit your needs—not just to get you across the finish line but to do it feeling strong.
Let’s build a plan that works for you. Reach out, and let’s get started.