Ranking Fitness Advice From Social Media (with Harley Pasternak)

April 13, 2026

AI Summary

5 min read

Harley Pasternak, a celebrity trainer with a master’s in exercise physiology and a client list that includes Lady Gaga and Halle Berry, joined Liz Moody to rank fitness advice from social media. The conversation quickly settled on a central tension: the internet obsesses over tiny, extreme details—like cortisol spikes and VO2 max scores—while ignoring the massive, boring inputs that actually determine health. Pasternak’s core argument is that most people should stop worrying about what is optimal and start worrying about what is sufficient, sustainable, and unlikely to cause injury.

Walking vs. Running and the Cortisol Trap

The first piece of advice came from an influencer who claimed walking is superior to running because running spikes cortisol and makes you hungry. Pasternak gave this a B tier. He agreed with the premise—walking is lower risk, requires no mental preparation, and does not trigger the same ravenous appetite as high-intensity work. But he pushed back hard on the idea that this means you should never run. “It’s not that you shouldn’t run,” he said. “It’s that you don’t have to run.”

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What you'll learn

1 (01:54) **Walking vs. Running & the Cortisol Myth** - Harley debunks the idea that running spikes cortisol and causes belly fat, ranking the advice a B.
2 (04:36) **Is Running's Higher Heart Rate Beneficial?** - Harley explains that while running has benefits, you do not need a high heart rate for longevity.
3 (06:47) **Supersets & The Myth of General Fatigue** - Harley explains how to structure workouts to avoid feeling "dead" while still getting results.
4 (16:49) **The Norwegian 4x4 & VO2 Max - Overhyped Indicators** - Harley ranks the popular VO2 max protocol as a C or D, and the concept of tracking VO2 max itself as an F.
5 (21:40) **The Real Drivers of Longevity** - Harley reframes the conversation from heart health to the actual top causes of death.
6 (25:03) **Cold Plunges & Post-Workout Nutrition** - Harley ranks specific social media advice on recovery.
7 (28:01) **Rest Days & The Two Types of Exercise** - Harley clarifies the crucial difference between "cardio" and "strength training."

+ Full timestamped outline available in the app

Guests on this episode

Liz Moody

Show Notes

With all the contradictory advice online, establishing the optimal workout routine can be SO confusing. So today, I’m joined by expert Harley Pasternak to rank fitness advice from social media to clear things up.

Harley has a masters in exercise physiology and nutritional sciences, he worked as an exercise and nutrition scientist for Canada's Department of National Defense, he's a five-time bestselling author, and he has the biggest celebrity client roster in the fitness industry—Halle Berry, Lady Gaga, Rihanna, and Ariana Grande to name a few.

🎧 What you’ll learn:

• How to structure a week of workouts with minimum time, maximum results

• Walking vs. running: which one is better

• When to lift heavy weights vs. light weights

• How important VO2 max is

• Why your body stops responding to exercise + the simple fix

• Where the 10,000 steps goal came from and if it’s legit

• If there’s a connection between cortisol and belly fat

• The difference between local fatigue and general fatigue and when to use them

• The single best thing Harley says you can do for your health

Check out the previous ranking episodes of The Liz Moody Podcast:

• Ranking Gut Health Advice From Social Media (with Dr. Karan Rajan)

• Healthy Eating Advice: Ranking Best & Worst From Social Media (with Nutrition By Kylie)

• Therapy Advice: Ranking Best & Worst From Social Media (with Lori Gottlieb)

• Money Advice: Ranking Best & Worst From Social Media (with HerFirst100K)

For more from Harley Pasternak:

• His Book, The Carb Reset: https://www.harleypasternak.com/books

• Instagram: https://www.instagram.com/harleypasternak

• Website: https://www.harleypasternak.com/

Ready to uplevel every part of your life? Order Liz’s book 100 Ways to Change Your Life: The Science of Leveling Up Health, Happiness, Relationships & Success now!

Connect with Liz on Instagram @lizmoody or online at www.lizmoody.com. Subscribe to the substack by visiting https://lizmoody.substack.com/welcome.Buy our cute sweatshirts, conversation cards, and more at https://shop.lizmoody.com/.

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