Building Muscle and Running: Does It Work?

Striking a balance between running and strength training isn’t easy, and often leads to confusion among runners. How can one boost endurance and build muscle mass at the same time? That’s a question I’ve been asked many times — because that’s exactly what I’ve been doing now for over two years.

Woman running in Brooklyn

Building muscle vs running performance: can you have both?

First things first: yes, you can. However, if you’re aiming high in both categories, there are a few things you need to bear in mind. Let me tell you how I managed to achieve great results in building muscle and running performance:

1. Nutrition is key

It’s a common mistake among runners to eat too little when trying to build muscle mass while working on their running performance. When I started running, I had no idea how many calories, how much body fat or how much muscle mass is burned by my weekly 60 to 80 km. I lost a lot of weight and my body fat percentage dropped drastically — until there was no femininity left, no female curves and muscles.

I made the mistake of not adapting my nutrition to the distance I covered running every week, which led to a constant calorie deficit. At the same time, my training sessions in the gym didn’t yield the results I was expecting. Why? Because my body had no chance to grow muscles from the nutrients I provided with my food intake. It’s like a car trying to run on an empty tank.

So, the opposite happened: instead of burning fat, my body resorted to energy from burning energy-demanding muscle mass. If your goal is to build and tone muscles while being an active runner, you need to keep this in mind. Make sure your nutrition provides your body with at least the calories you burned when running. The best way to do that is with a healthy, balanced diet including foods high in protein (fish, chicken, eggs), vegetables and carbohydrates (sweet potatoes, brown rice, oats).


Especially after a training run, your body needs energy. This helps you recover and fills up emptied stores post-workout. After a long weekend run, plan for additional carbs and protein — the long training runs really deplete your energy reserves and, therefore, can substantially reduce your muscle mass.

If you’re planning to do a strength training session, make sure you fill up on carbs one hour prior to your workout. Your body can then directly transform them into energy during your training. Plus, stay away from alcohol and sweets. I know they are tasty, but they are also really counterproductive to your fitness goals.

2. Be smart about combining endurance & strength training

I would not recommend running on an empty stomach in the morning when your goal is to grow muscles. A light breakfast – like oats or a banana – is enough to provide your body with the energy needed for a run. And you get to keep the muscles you trained so hard for.

Based on your personal goal when it comes to growing muscle mass, reducing your weekly runs’ mileage might make sense, especially in the early building phase of your strength training. Short, fast runs and sprints have positive effects on building muscle in your legs and upper body.

Young woman is doing front-to-side raises

Additionally, the number of training sessions per week influences the results you see. A smart combination of endurance and strength training is vital here. Depending on your training frequency, you should try to work out your legs and plan a fast run on the same day. This is important to make time for proper recovery. I usually head out for a run on Monday morning, followed by a leg training session in the evening.


Make sure your break between training sessions is at least 6 hours. The day after is reserved for regeneration and recovery. This is vital because that’s when your body really starts getting results (not while you’re working out, as many people assume).

The combination of running and strength training is a double burden for your body, which makes two rest days per week a must. It’s worth it though: as soon as your body gets used to the new training schedule, you’ll see results real soon.

3. Supplements: BCAAs, glutamine and protein

First of all, let me tell you one thing: all bodies are different. Based on our genetics, age and fitness level, our individual necessities are different. There’s no magic cure, but supplements can effectively boost your training results.

In my training, three supplements play a major role: as soon as your glycogen reserves are empty during a longer endurance training, the body resorts to protein stored in your muscles. Branched-chain amino acids (BCAAs) aid regeneration and help maintain muscle tissue. The three BCAAs leucine, isoleucine and valine are essential for growing and keeping (!) muscle tissue. They support protein synthesis in the muscles. At the same time, they inhibit the breakdown of muscle protein and improve regeneration processes. This means that BCAAs aid in just what runners need: maintaining muscle mass.

Woman running in Brooklyn

Glutamine, another amino acid, might be worth a try when training with high frequency — which definitely happens when combining running and strength training. Glutamine guarantees that your glycogen reserves are filled up as fast as possible. Glycogen is a storage form the body produces from the carbohydrates you eat and is mainly stored in muscle cells. It’s an essential energy provider during physical efforts. Empty glycogen reserves mean less energy for your training, and that’s something you want to avoid. Glutamine works best when taken after a training session.

Protein powders low in sugar are another item on the typical runner’s supplement list as they ensure sufficient protein supply. Post-training I like to fill up on “the real thing” by eating egg whites or chicken. However, protein shakes are a much quicker and still valid option.

In a nutshell, a clever mix of nutrition, supplements as well as endurance and strength training makes it possible for runners to boost their performance and build muscle, too.

About Sabrina:

Woman in Central Park

Sabrina is known as runningbrina in the fitness world. As a certified running coach in New York City and Runtastic Ambassador for the US, she has combined her running training with active bodybuilding for the past two years. She shares her experiences and training and nutrition tips on her blog as well as on Instagram.



Sabrina Wieser Sabrina works as a running coach in New York City. For the past two years she has been combining her running with active bodybuilding. View all posts by Sabrina Wieser »