Training For Marathon and Building Muscle (Is It Possible?)

In the marathon scene, it’s custom to see skinny athletes racing to the finish. After all, training for a marathon burns a lot of calories which explains their skinny physique. But is it possible to build muscle while training for a marathon?

In general, marathon runners can build muscle if they find the right balance between running and strength training. Having dedicated time to resistance training is key to muscle building. Replacing the calorie expenditure by increasing your calorie intake is also an important factor in the process. 

Ahead, we will look into some of the factors why marathon runners often have smaller muscles. I will also give you tips on how to run and still build muscle.

Can Marathon Runners Build Muscle?

It’s a custom belief in the fitness community that running and other aerobic exercises burn muscle. The belief is so popular, so much so that runners are skinny and strength athletes can’t run has become a stereotype.

However, there are more and more athletes with the likes of David Goggins (he even runs 100-mile races multiple times), Cam Hanes (ultramarathon), and Nick Bare (sub 3 marathon) proving that there is a middle ground between running and building muscle.

To add to that argument, take a good look at Austin Maleollo, an 8-time Crossfit Games competitor, who deadlifted 600 lbs right before lining up for the 2019 Boston Marathon. Yes, you heard that right, 600 lbs moments before running a marathon at 4:27:45.

(If you want to check out what Austin has to say, has the full interview of Austin Malleolo).

So, can marathon runners build muscle? Absolutely!

The key to building muscle and training for a marathon is a balance between weight training and running. In addition, having a high-calorie balanced meal is very important to support muscle growth.

Take a look at Nick Bare’s workout routine in the youtube video below.

Can Running Build Muscle?

The current belief on aerobic exercises is that it has a very minimal effect on the size of your skeletal muscle.

Contrary to popular belief, research conducted by the Mayo Clinic College of Medicine in 2015 suggests that aerobic exercises such as running induces skeletal muscle growth by altering the protein metabolism.

However, the research was done on sedentary individuals.

The way to grow your muscles is by providing enough overload which results in muscle hypertrophy (muscle growth). Running provides the necessary stimulus to promote hypertrophy for inactive individuals.

Even so, their muscles will stop growing when their body starts to adapt to the activity.

Therefore, we can assume that only resistance exercises such as bodyweight exercises, resistance bands, and weightlifting, are the only effective way to increase noticeable skeletal muscle mass.

Will I Run Slower If I Build Muscle?

A lot of runners believe that the bigger you are, the slower you get. While there are some facts to that, that’s not necessarily the case if you train the right way.

In general, building muscle will not make you slower. In fact, it can even make you faster. Stronger muscles help exert more power into each stride. In addition, having good muscular endurance is also important in resisting fatigue allowing you to hold a faster pace longer. 

When people say athletes with big muscles are slow runners, it’s almost a guarantee that they’re talking about a serious bodybuilder or powerlifter physique who has little to no training in the running department (sorry folks).

They spend most of their time training for what they’re competing for that they often neglect to include enough cardio in their training. But, that’s what they have to do.

Elite athletes train for perfection, and when you’re training for perfection, you can’t afford to stray away from your goal by training something else.

They chose to sacrifice running to achieve perfection in their sport.

Therefore, they can’t run fast simply because they haven’t trained for it, not because the muscles made them slower.

For beginner to intermediate and even advanced runners, there’s no reason to stay away from one type of exercise to focus on the other. Building muscle (as long as it’s not the Mr. Olympia level) is ideal and it can definitely help you run faster and more efficiently.

If you want to find out more about how building muscle affects speed, I made a detailed article about this topic including the protocols that you have to do to build muscles that will help your running. Make sure to check that out.

Why Do Marathon Runners Have Smaller Muscles?

Perhaps another question that pops up when people talk about running and muscle building is why runners have smaller muscles.

Although the custom answer is that marathon runners have smaller muscles because they always run, that’s not exactly true.

In general, elite marathon runners have small muscles because they spend less time trying to build muscles and more time running. In addition, being light also gives them an advantage in running long distances so they try to stay that way. 

But it’s worth pointing out that you don’t have to be thin to be good at marathons.

In fact, some of the best marathon and ultramarathon runners in the world have a muscular physique considering they balanced their running and strength training well.

This goes back to what I said earlier about prioritizing your sport. Elite marathon runners who actually win marathon races like Eliud Kipchoge are thin because they have to spend much of their time running to be great at what they compete at.

There are only so many hours in a day and days in a week to be training both running and strength at a very high level. Add that to the fact that you still have to give your body enough time to rest and recover.

How Much Running Is Too Much For Muscle Building?

While there’s no exact answer on this matter. In general, running for 2 to 3 hours a day for 5 days a week may prevent you from allocating time for strength training and recovery. 

The minimum hours spent on running while training for a marathon is somewhere around 1 and 1 1/2 hours depending on your level of experience.

If you increase your running time to 2 to 3 hours a day to increase your weekly mileage, you may find it hard to insert a strength workout in your program.

Some experienced marathon runners recommend cutting back on the weekly mileage to a minimum to free up time for a strength program. Other runners simply maintain their weekly mileage but increase their training time and adding 30-45 min upper body strength exercises such as military press, barbell rows, push-ups, and pull-ups.

How To Effectively Build Muscles And Still Be Able To Run a Marathon

Now that you know that building muscle while training for a marathon is possible, let’s now look at how we do it.

Increase Your Calorie Intake

Contrary to the common belief on performance, cutting back your calories does not correlate with a boost in performance.

Food is fuel and athletes need to fuel their bodies to support their activity.

If you’re training for a marathon and trying to build muscle at the same time, it is best if you can maintain a surplus of 500 to 1000 calories to support muscle growth.

That means, if you weigh 160 lbs, you’ll burn 1800 to 2700 calories in a 2-3 hour training session (including the strengthening). If your basal metabolic rate (calories you burn without activity) is around 1700, the amount of calories that you burn each day is around 3,500 to 4,400 calories.

Therefore, you should have a calorie intake of 4,000 to 5,400 calories per day to support your marathon training and muscle growth.

Don’t get me wrong. I’m not talking about binge eating fries at McDonald’s or eating a tub of ice cream each day. The food sources matter too. Aim to get your carbs, fats, and protein from good sources.

Run In The Morning, Lift In The Evening

If your time and energy allow, you should try working out twice a day.

Run your regular mileage early in the morning and spend 30-45 mins in the afternoon lifting weights.

Avoid going heavy for now. You want to keep the intensity to a minimum to allow your body to recover from training.

Do Compound Exercises Only

While it’s tempting to see those bulging muscles and well-defined shoulders in your mirror selfies, I highly encourage you to avoid isolated movements such as bicep curls and lateral raises. These exercises do well for muscle definition but are not so good at building muscle mass.

Instead, do compound exercises like deadlifts, squats, military press, and bench press. These exercises target several muscle groups all at once which is a more efficient use of your time.

Compound exercises are also linked to an increase in testosterone levels that could help you build muscle faster.

Here’s a list of the exercises you should and shouldn’t do.

Do’s (compound exercises)

  • Squats
  • Deadlifts
  • Military Press
  • Bench Press
  • DB/BB Rows
  • Push-Ups
  • Pull-Ups
  • Lunges
  • Step-Ups

Don’ts (isolated exercises)

  • Bicep Curls
  • Tricep Extension
  • Front Raises
  • Lateral Raises
  • Tricep Kickbacks
  • Leg Curls
  • Leg Extensions

Eat Or Drink Carbohydrates Every After Exercise

Whether you’re running or you’re lifting, always remember to eat or drink carbs within 1 hour after your workout. This will replenish the depleted glycogen in your muscles to support your next workout.

Although high-quality food sources like bananas are preferred, orange juice and chocolate milk will work the same way.

Key Takeaways

To help you put all this information in a digestible format, I put together the key takeaways in a bulleted list:

  • It’s possible to build muscle while training for a marathon
  • Running is not the culprit as to why runners have small muscles, it’s lack of strength training and calorie intake
  • Elite runners are skinny because they spend most of their time running; strength athletes are slow because they spend most of their time lifting
  • Only resistance exercise can build your muscle, therefore, you should include a strength program in your marathon training plan if you want to build muscles
  • Find the perfect balance of strength and cardio
  • Have a calorie surplus of 500 to 1,000 calories to support muscle growth
  • Do compound exercises

Nicho Mauricio

Running wasn't always my favorite sport. I was a CrossFit athlete and I loved every bit of it. But since the pandemic began, I was forced to stay away from the gym and train at home instead. Things got boring. That's when I decided to trail run with my friends. I instantly got hooked. So I started training and researching all things running. As a beginner, I want to buy only the best running gear and do only the best practices. This blog is where I share what I've learned in my journey and my experiences as a runner.

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