Does Running Build Muscle? Surprising Facts About Strength Training For Runners


We all know that if you want to look like you work out, you have to do strength training. You can get your biceps, legs, and core looking nice and toned. While running does build muscle strength, it doesn’t work quite the same way as resistance training.

This article addresses that very issue. We’ll discuss why strength training is important for runners. Then, we’ll cover how you can add strength-building workouts to your running routine.

What’s the Difference Between Muscle Strength and Bulk?

Running will build muscle strength, but it won’t bulk you up to look like a weightlifter. You absorb 2-4 times your body weight when you land during running. This can contribute to muscle growth, especially if you’re new to running.

According to one study, aerobic exercise like running will produce some skeletal muscle growth. You don’t necessarily need to do leg day at the gym to build muscles in your legs from running.

That said, if you’ve been a runner for a long time, you probably won’t be able to build additional muscle mass. There’s even a question as to whether you’d want to. You’ve already seen the gains running produces. You might see some more definition on your muscles, but you probably have reached the limit for increasing slow-twitch muscles.

You can start to build more muscle again by harnessing your fast twitch muscles. This can be by doing sprints or any kind of high-powered short exercise that you haven’t typically done. It needs to be harder and faster than previous workouts. Hill workouts are a great option.

You can also add strength training to your schedule. It will improve your running in many aspects. This includes improved endurance, maximum sprint speed, running economy, and running performance—as one study found. Plus, it will help prevent injuries and keep you nice and healthy.

Does Running Burn Muscle?

Elite runners are, generally, super slender, which might make you wonder if running burns muscle. The short answer is no, unless your body runs out of other fuel to burn. In other words, if you don’t have many energy stores in other places, your body will use muscle protein. But that is an extreme scenario.

This isn’t necessarily unique to running. It works the same way for strength training. This means that you need to make sure that you’re giving your body enough fuel. If you don’t, it will burn muscle instead of preserving that muscle mass.

One coach recommends consuming foods with carbs so that muscle doesn’t continue to break down as much after you exercise. You’ll need to do this during your run if it’s going to last more than 45 minutes.

The key is making sure that you maintain a balance of muscle burning and muscle building. It’s okay if you have a little bit of muscle protein breakdown, and you don’t have to feel like you have to be lifting weights every day.

But you also should make sure that you have plenty of fuel for your body so that it doesn’t have to resort to muscle burn.

Why Are So Many Elite Runners Thin With Minimal Muscle Mass?

If you think about it, this is only true for distance runners. If you regularly run over 10 miles, then you’re likely going to be thin and not have too much muscle mass. This is a bit of a chicken-or-egg question. Elite distance runners put in huge amounts of work, often more than 100 miles per week. That burns calories and makes muscles toned and efficient. Plus, they take the time to do gym work and stretching. They have their diets monitored by nutritionists. Running is their livelihood, so of course they are slim and trim. After all, less weight in your body means that the power you are putting down moves your mass faster. 

But this isn’t true for sprinters and mid-distance runners.

In fact, such runners focus on building muscles for strength and power. Just think about the Olympics. Sprinters like Usain Bolt are not super skinny. Instead, he has a powerful build that is perfectly suited for the explosive sprinting he is so good at.

The reason why distance runners don’t bulk out is because they need to focus on being as light as possible. This helps them to run faster for a longer distance and a longer period of time.

Should Amateur Runners Build Muscle?

Yes. Chances are that if you’re reading this article, you’re not an elite long-distance runner. You should definitely work on building muscle.

Strength training will make you a stronger runner and help prevent injuries. Other benefits include:

Reducing Fatigue

First, you won’t tire out as quickly. One study found that you’ll be able to run 21% longer before you get tired just by adding some squats to your training. That’s huge!

Running Faster

Second, you’ll be able to run faster because you have stronger muscles that can give you a faster transfer as you switch from foot to foot.

Running Better

Third, you’ll improve your VO2 max, and you’ll be able to use oxygen more effectively. This means that you’ll up your running economy game. You’ll see that gain regardless of whether you’re new to running or have been doing it a while, one study found.

Less Likely to Get Injured

Finally, runners are prime candidates for getting injured due to structural weakness. If you want to reduce your risk for injury, you need to add some strength training into your routine.

One study found that strength training can help to cure IT Band Syndrome, and that’s true for a whole host of other injuries. But you’ll have to be doing some cross-training and hitting the gym as opposed to running every day.

How Can I Build Muscle Strength When Running?

There are a variety of ways that you can build muscle strength even as you maintain your running routine.

We’ve listed a few below. These are great options, so be sure to experiment with them and intersperse them into your training program.

Include Strength Work in Your Weekly Training Routine

First, make sure that you’re doing some sort of strength training every week (TRX is a good option) (TRX is a good option). This can range from squats to pull-ups to machines at the local gym. Focus on low weight and a high number of reps.

You’ll also want to work on your core strength, which you can develop through crunches, planks, and similar exercises. If you want to run fast, you must have a strong core. All of these additions will make you a stronger runner.

Add Hill Workouts to Training

Another great way to build muscle while you’re running is to complete hill workouts. As Frank Shorter stated, “Hills are speed work in disguise.” Hill workouts allow you to target a wide variety of muscle fibers that you wouldn’t work during a slow, steady-state run.

You’re also less prone to injury when doing hill workouts as compared to speedwork because you aren’t pushing your body to go too fast. You just have to get up the hill.

Your best bet is going to be short hill reps, so that you have to push a little harder than a long hill workout.

Add Speedwork to Training

Speedwork will build strength because you’ll be drawing on your fast-twitch muscle fibers as we mentioned above. It’s important that you don’t overexert yourself when doing speedwork, but it does need to be at a brisk pace.

Your slow and easy runs really should be slow and easy. You should be able to have fun talking with your friends or just getting absorbed in a good book or podcast. But you need to push hard during your speedwork, giving yourself at least an equal time of rest between sprints/intervals.

Typically, you’ll likely want to do short intervals like 100-200 meters or ¼ mile sprints. You want to push hard during those intervals. You’ll feel super sore afterward, but you’ve built some muscle!

Focus on Nutrition (Including Protein)

While exercise is all well and good, you can’t forget the important role that nutrition plays in building muscle mass and strength. When you’re starting to build muscle, try to get 10-35 percent of your total calories from protein.

After you’ve built it up, you’ll need less protein to maintain it. Typically, you’ll need only three servings of protein foods. Good options are beans, fish, lean meat, and poultry. For a 150-pound adult, this works out to 56 grams of protein a day.

As an example, you’ll find 26 grams of protein in 3 ounces of skinless, baked chicken, 22 grams in 3 ounces of lean ground beef, and 21 grams in 3 ounces of grilled salmon. These are all great dinner options.

You’ll also want to make sure that you’re consuming enough carbs and fat to give your body the energy it needs to strength train properly. Good options include high-quality carbs like whole-grain breads and cereals, or heart-healthy fats like avocados and nuts.

Final Thoughts

Back to the original question. Yes, running does build some muscle. But that doesn’t mean that you should forego strength training. Rather, to get the best of both worlds, you should have a nice mixture of running and strength training.

As you add in ways to build muscle strength, make sure that you don’t forget about your diet. It’s important to get enough protein, carbs, and fat play in building muscle. As a runner, you’ll never look like a weightlifter, but you can look nice, defined, and toned!