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TOP 3 Lies Runners Believe about Lifting Heavy

Raise your hand if you've ever had a bad run.

Now raise your hand if you've ever thought your body was blame.

Kind of weird, isn't it?

The exact thing that makes running possible is the exact thing we blame for not being good enough, running fast enough, going long enough,…fill in the blank.

Do you want this year to be the year?

The year you turn things around and run your absolute best?

(I mean, who doesn’t?!)

Then you might need to get out of your own way.

I said what I said.

Because here's a tough love question to ask yourself:

What's holding you back from stepping into the gym? What's keeping you from lifting heavy?

It's not the hard work.

You're a runner!

You thrive on challenge.

You adapt to adversity.

You (literally) go the distance and don't give up!

But maybe it's the lies living in your head rent free that are holding you back from running your best?

I'm willing to bet these lies are even the ones NOT supported by the

Science calls your bluff.

Science says they're bull cookies.

And you know what's on the other side of all this? You running your freaking best, fastest, strongest YEAR EVER!

You ready?

Lie #1: "If I lift heavy, I'll get BULKY!"
"The belief that negative adaptations in body composition will result from concurrent training is a common misunderstanding that is NOT supported by the literature at large"


"weight gain, body composition changes, and limb girth measurements do not change significantly in male and female distance runners performing concurrent training."

How come?

Because of the interference effect.

"the interference effect explains that the adaptation to endurance or strength performance may be hindered by the participation in the other form of training."


"a long running training session blunts the protein synthesis response needed for strength and hypertrophy gains for 3-12 hours after exercise, therefore compromising optimal strength development."

Diving deeper, because a long distance running training plan requires so many runs of long duration,

"there may be insufficient intersession recovery time between running sessions to fully realize the anabolic stimulus from resistance training."

This effect is actually WHY long distance runners won't get "bulky"!

The physiology-stars just don't align.

The flip side to this however, is you need enough recovery time between your runs and your strength workouts (4-6 hours) to gain the positive effects of lifting.

Lie #2: "I have to be at race weight."

TRUTH: Here's why this nonsense persists. Because there is a kernel of truth in it.

"No associations between body fat and race pace were found in (marathon and ultramarathon) runners if their body fat measured below 15%, indicating that body composition for distance runners…seem to be of less importance if the runners have a relatively low level of fat mass."

*rewind scratch*

What they're saying: once your body fat mass is 15%, there are NO MORE pace advantages if you drop lower than that.

But here's the REAL kicker: in this study, there were 340 MALES and 1 FEMALE.

WHY this matters:

That top row: "Essential Fat".

This is the MINIMAL amount of body fat you need to SURVIVE.

(And in my opinion and based on other research I've seen, the minimal essential fat for women is more the 13% and maybe as high 15%. That 10% is for the birds...)

More reasons you need fat:

Fat is one of the building blocks of hormones.

Hormones help you grow, know when you're hungry, know when you're full, build muscle, and support reproductive health.

(Known fact: women elite runners sometimes have to stop running as aggressively as they normal do so they can maintain enough fat mass in order to sustain a successful pregnancy.)


So why the race weight conspiracy?

"runners with a high proportion of skeletal muscle mass and low fat mass may have an advantage in reducing the absolute energy cost of running."

The TRUTH of physics: you need more energy (work) to move more mass (weight). The lower the fat mass, theoretically, the faster you are. But what a lot of runners forget: muscle adds weight too.

But the good kind of weight. The weight/mass that generates power, speed, and endurance.

So flip that script with this quote:

"This study suggests that it is advantageous to be a runner with a high proportion of lean muscle mass as compared to body fat."

Build that muscle.

Don't be afraid of your own strength.

And even if your "fat mass" is higher than you like, that strength and muscle mass you're building is keeping your body and joints healthy!

The aerobic endurance you're building is keeping your heart and lungs healthy.

I promise, your body will thank you for years to come.

Lie #3: "If I lift too much, I'll get SLOW!"

It's actually the exact opposite.


"two recent systematic reviews on concurrent training generally found negligible changes in body composition measurements but still reported improvements in running performance in both female and male runners"

Chalk another one up for "you won't get bulky" if you're a long distance runner who lifts.

And…don't miss the AMAZING benefit of lifting: "improvements in running performance."

What are they talking about?

"strength-focused resistance training session for a competitive distance runner may result in positive adaptations to the skeletal muscle (and the system), induce changes to the running economy, and result in no gross body composition changes."

Lifting will actually make running EASIER by helping make YOU a more efficient runner. And when you're an efficient runner, you can run faster and/or run longer.

What runner doesn't want that??


Regularly strength training 2-3x a week won't turn you into the hulk.

And lifting heavy won't slow you down to a snail's pace.

Instead, the opposite will happen:

  • You grow and gain lean muscle mass.

  • Harness more power.

  • Build strength.

  • And be able to run longer and faster.

So how do you feel NOW about going to the gym and getting your lift on? Ready for the best running year of your life?

Looking for an easy, running-specific place to start your running performance transformation? Check out my FREE running guide to grab some running strength exercises! You'll be glad you did ;)

Got more questions about lifting and general strength training for runners? Leave your questions in the comments below: I can't wait to answer them and chat!

Until next time, Dare to Train Differently,

Marie Whitt, PT, DPT //



Barrie, B. (2020). Concurrent resistance training enhances performance in competitive distance runners: A review and programming implementation. Strength & Conditioning Journal, 42(1), 97-106.


PennRec Body Composition Fact Sheet

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