New York City, NY

How to Maintain Muscle Mass as a Runner


By Amanda Jane Snyder

One would assume running would equal fat loss. Or at least exercise high in cardiovascular activity and calorie burn would equal fat loss. But studies show that not only does running result in fat loss... it also can result in loss of muscle mass!

But if we're losing weight does it really matter where it's coming from?

YES! And here's why.
Image copyright of Drew Reynolds.

I have to admit. As a personal trainer I’ve spent most of my career promoting weight training, or at least resistance training of some sort. Why? Because I enjoy it first of all. Second of all, resistance training has so many benefits including preventing osteopenia and osteoporosis. It is the key component to achieving that desired “toned” look that every one and their mother seems to be after; you cannot achieve the aesthetics of “toned” muscles without muscle… plain and simple. Additionally, resistance training puts your body out of its natural state: homeostasis. Your body ends up burning calories 24 hours AFTER you complete the workout as your body works to get back to homeostasis. Weight training has aided me in shaping my body exactly the way I want it. I’ve felt strong, I look good.

I never liked or promoted running to my clients...until a little over a year ago when I decided to run the NYC Marathon...

So why did I assume when I signed up for the New York City Marathon that running 20-30+ miles weekly would magically shed my excess lower belly, back, and under booty fat?

WHY you’ve THOUGHT Running = Fat Loss and Fat Loss ONLY.

Don’t get me wrong, running has it’s place. Cardiovascular exercise is important! But endurance running does not necessarily correlate with fat loss. So why do we think it does?

High Calorie Burn

In some of my marathon training days I would burn an absurd number of calories in one session. I would burn something like 2500 calories in one session. ONE RUN. ONE RUN and I BURNED 2500 CALORIES!!! That is a lot of calories to expend in one exercise session. And for the most part, we associate calorie burn with fat loss. Burn more calories = burn more fat right? More on this later.

Proof is in the Pudding

What’s another reason why we associate running with fat loss? Because all the elite athletes are skinny AF.

I mean just look at these people. Do a quick google search of Eliud Kipchoge, one of the most elite long distance runners of our time to just give yourself a visual. Skinny. AF.

Like woah why wouldn’t we assume running means low fat?

Why Running DOES NOT = Fat Loss and ONLY Fat Loss.

High Calorie Burn Doesn’t Result in Weight Loss

Ever thought about this? The more energy you’re burning… the hungrier you are. Believe it or not it IS possible to still GAIN weight even while burning 2500 calories in one workout. HOW? By eating MORE calories then you burn throughout the day. Calorie burn DOES NOT EQUAL WEIGHT LOSS. The only way to lose weight is to be in a caloric defecit. Meaning, consuming LESS calories than you’re burning throughout the day.

A Study… on Myself

On day one of my marathon training I took an InBody Scan. These Sans measure Body Composition including Weight, Body Fat Mass, Body Fat Percentage, and Skeletal Muscle Mass amongst other things.

My Results on day one (July 19, 2019) included an overall weight of 138.7, skeletal muscle mass of 61.3, and a body fat mass of 28.9 all measured in pounds (lbs).

Over the course of a month my running increased A LOT. I went from running maybe once a week (if I felt like it), to running 3-4, sometimes 5 times a week. My running increased from 3-5 miles a week to 20-30 miles a week. My overall calorie consumption didn’t change much; Admittedly I didn’t track my calorie intake, but I also didn’t make any drastic changes besides increasing my cardio.

After the first two weeks of running, I scanned for the second time. My weight decreased by approximately 4lbs (134.9), but my body fat mass only decreased by .3. So what happened?! MY SKELETAL MUSCLE MASS DECREASED! In this mid scan, I was expecting to see my body fat percentage decreasing like crazy. After all, I was running around like a crazy person… LITERALLY.

Here’s the catch with running: when you’re burning calories through cardio endurance training, you’re not just burning fat, but muscle as well. And less muscle mass means less efficient calorie burn. How so? Because more muscle mass means a higher metabolic rate. A higher metabolic rate means more calories burned while resting.

So what's the best way to lose fat while NOT losing muscle?

Maintain a consistent resistance training routine and UP your protein intake.

Not only will resistance training help with preventing injuries and any imbalances you may have as a runner, but it will prevent muscle loss.

Be sure to include proper fueling techniques such as fueling BEFORE your workout and AFTER. Post workout should include at least 1-1.2g/kg of bodyweight of carbs and .25-.3g/kg of bodyweight of protein. And thats just for the post workout meal. Make sure you're getting adequate carbs and protein throughout the day as well!

AND Balance. I know. The sexiest word you’ve ever heard but it’s true.

Have a balance of resistance training AND cardiovascular exercise, PAIRED with a caloric defecit IF you're looking to lose weight. All three working together in tandem will produce optimum fat loss results without muslce loss.

And honestly… don’t over do it. Too much stress on the body (yes, exercise is a form of stress), can produce too much cortisol, a hormone released during exercise. Corisol is not all bad BUT too much cortisol can result in insulin resistance and excess storage of belly fat.

Amanda Jane Snyder is a Certified Strength and Conditioning Specialist, Corrective Exercise Specialist, Certified Personal Trainer, and Mindset Coach living in Brooklyn, NY. She has been vegan for 4 years. She specializes in Strength and Conditioning for Actors, Singers and Dancers.

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Amanda is a Certified Strength and Conditioning Specialist, Certified Personal Trainer, Group Fitness Instructor and Lifestyle/Mindset Coach! In the midst of the ever-changing fitness industry chock full of fad diets, Amanda uses her program ForeverFit to help clients find true success through habit change, routine, and making health and fitness apart of their LIFESTYLE! Amanda is powered by plants!

Brooklyn, NY

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