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Cross-Training

We Know You Want to Know: Does Running Build Muscle?

The short answer is: Kind of.

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Building muscle is a noble goal for any woman. Especially when you think about how we start to lose muscle mass around age 30 thanks to age-related biological processes. In inactive people it can be as much as 5 percent per decade. 

Early to middle adulthood is the best time to get started combatting age-related muscle loss, but in reality nearly every adult woman should be thinking about strength training. 

But is running enough to keep even our baseline muscle mass? 

Building muscle, or hypertrophy, comes down to time under tension, says running coach and personal trainer Erika Canales. At its most basic, it occurs when muscle protein synthesis exceeds muscle breakdown.

As far as muscle loss goes: “You can stop it,” says Canales, “but you have to have a good and appropriate strength training program. Running by itself won’t help with that per se.”

Canales, who is also co-owner of Outright Fitness, says that beginners are most likely to experience the muscle building effects of running. That has been verified in research, finding that sedentary people experience skeletal muscle growth when adhering to a new running or walking regimen. But that can only take you so far. “How you really develop strength is through actual strength resistance training,” says Canales. 

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That’s not to say that running is doing nothing. It just builds a different type of muscle than what we’d typically consider ‘gains.’ 

Within your muscle fibers, you’re either affecting endurance, strength, or power, explains Natalie Niemczyk a doctor of physical therapy, running technique specialist, strength and conditioning specialist, and run coach with Revolution Running. “Long distance and recreational running hits endurance, but it doesn’t hit the other aspects,” she says. 

Skeletal muscles are made up of muscle fibers: slow twitch and fast twitch. You can thank your slow twitch fibers for your ability to sustain a long run as they are more fatigue resistant. They help you sustain smaller movements for longer and help to hold your posture. When you run you are contributing to these muscles.

Fast twitch fibers, on the other hand, are responsible for power and force—strength. As such, high-intensity, short duration running has been shown to promote this type of muscle growth over long distance running.

“Running definitely tackles more into that specific muscle fiber that focuses more on endurance training, which goes hand in hand with the cardiovascular system,” says Niemczyk.

Beyond preventing age-related muscle loss, strength training can also benefit runners by building protective measures against injury and even improving running performance. For example, strength training programs lasting 6-20 weeks long have been shown to improve running economy by 2-8 percent.

Muscles are not the only marker of strength, though. Building up bone and tendon strength is just as important, especially to protect ourselves from injury. 

While running does help to build bone strength, other high intensity fast movement, like jump training or the variety provided in lifting, also do the trick. For building tendon strength, Niemczyk recommends heavy, slow lifting.

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Niemczyk recommends full squats, over single-leg squats, as a way to introduce more weight into training. (Photo: Getty Images)

One thing Niemczyk sees runners do a lot is focus on their arms on their gym days because they assume running is working their legs enough. “You really need heavy squats and deadlifts to really strengthen the legs to protect you while you run,” she says. And heavy lifting is often in the plan for her physical therapy patients who are rehabbing injuries related to bone strength, tendons, or soft tissue.  

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So what should runners focus on when thinking about building strength? Intensity, consistency, and duration of the training program, says Canales. 

“I​​f you’ve never lifted weights, you would start your program with an assessment to see where you are, how much you want to lift, or how much you can lift and then build from there,” says Canales. 

A session with a personal trainer will also help to teach you the proper form so you don’t injure yourself that way.

Niemczyk lays out a simple strength routine that runners can follow without stealing too much time away from the activity they truly enjoy. In just one day a week you can focus on squats, deadlifts, overhead press, and chest press to weight train your key muscle groups just enough without fatiguing them too much. However, seeking out an individualized training plan will give you the best results in evening out any imbalances you have.  

It’s a great workaround for runners who say they don’t have time to strength-train. “If you give one day and you do 45 minutes, and you get in, you warm up properly, you make sure you do those movements right, with a heavy load of five sets of five and get out,” says Niemczyk.

Surely we can all find 45 minutes (and maybe more) a week to dedicate to our muscles. An older version of yourself will be grateful you did.

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