Brady Holmer sits down with Dr. Marc Bubbs — performance nutritionist, author, and creator of ProBio Nutrition — to break down everything runners need to know about gut health. From identifying food triggers to fueling on race day without GI disaster, Dr. Bubbs shares 20+ years of experience working with Olympians, pro athletes, and everyday runners. Whether you're dealing with chronic bloating or trying to push your carb intake past 60g/hour, this episode has you covered.

Brought to you by ProBio Nutrition - your all-in-one daily supplement for runners. Get 40% off with code RLRH (or 50% off + free shipping with a subscription) ➡️

https://bit.ly/ProBioRLRH

📚 Dr. Bubbs' books: Peak and Peak 40

🌐 drbubbs.com | probionutrition.com

📱 Follow Dr. Bubbs on Instagram & YouTube: @drbubbs

0:00 Introduction & Dr. Mark Bubbs' Background

1:07 Crossover Between Elite Athletes & General Population

2:04 Gut Health as a Buzzword — What Does It Actually Mean?

2:47 The 4 Pillars of Good Gut Health (King's College Framework)

5:47 Three Gut Health Scenarios: Poor → Good → Great

6:19 Scenario 1: Red & Yellow Flags — When to See a Doctor

9:14 The Difficulty of Identifying Problem Foods

9:54 Exercise-Related vs. Everyday GI Symptoms

11:42 Why You Should Start With Breakfast

12:07 The 3-4 Hour Detective Method

13:59 Can GI Symptoms Actually Be Resolved?

15:02 Eating Out vs. Cooking at Home

16:09 Are Food Sensitivity Tests Worth Your Money?

18:37 Scenario 2: When Running Triggers GI Distress

19:48 How Getting Fitter Improves Gut Diversity

20:57 GI Symptom Rates: Ultras, Ironman, Team Sports & Running

22:50 Finding Your Carb Intake Inflection Point

24:17 Gut Training: Titrating Up From 60g/hr

25:36 Is Pushing Above 80g/hr Worth the Risk?

26:00 Fueling Advice for Slower Marathon Runners

26:56 — AD BREAK —

28:08 Best Ways to Train Your Gut

29:06 Race Day Anxiety & the Gut-Brain Connection

31:20 Building Gut Health Over Months of Training

31:41 The 30 Food Diversity Challenge

33:08 Does Getting Fitter Reduce GI Symptoms? (The Bell Curve)

35:12 Probiotics for Colds, Travel & Performance

36:30 Race Week & Race Morning: What to Do and Avoid

38:47 Pro Tip: Caffeinated Gum Before the Start Line

39:06 The Golden Rule — Don't Try Anything New on Race Day

39:30 Carb Mouth Rinsing: The Placebo That Works

40:00 Scenario 3: Optimizing Gut Health for Performance

41:08 Prebiotics Explained — Seeds for Your Gut Garden

43:47 Best Whole Foods for Gut Health (By Category)

46:28 The Truth About Processed Food & Your Gut

47:47 Knowledge vs. Execution: The Real Friction Point

49:00 ProBio ProBlend: Why Dr. Bubbs Created It

53:00 Where to Find Dr. Bubbs, His Books & ProBio

Thomas and Brady discuss the potential negative effects of long-term running on your heart, and the potential increase in mortality risk. How worried should regular runners be?

Brought to you by ProBio Nutrition - your all-in-one daily supplement for runners. Get 40% off with code RLRH (or 50% off + free shipping with a subscription) ➡️https://bit.ly/ProBioRLRH

00:00 What does decades of running do to your heart?

03:53 The physical changes in your heart

06:10 Calcium

07:50 How much running causes these changes?
09:11 Stress and the heart

11:11 “Show me the bodies” - mortality risk?

15:28 “wear and tear” - valid?

18:18 - signs and symptoms of heart issues

23:20 Men and women, the differences

24:50 Study - masters athletes training vs heart episodes

32:45 Has Brady changed his training based on potential future heart issues?

The study referenced:
The timing and relationship of ventricular arrhythmia with exercise patterns in veteran male endurance athletes

https://academic.oup.com/eurjpc/advance-article/doi/10.1093/eurjpc/zwag021/8417747

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Thomas sits down with Marco Altini, prominent researcher in HRV, advisor to Aura, and dedicated ultrarunner, to discuss one of the most talked-about metrics in the running world today: Heart Rate Variability.

Marco's Substack:

https://marcoaltini.substack.com/

Marco's series of guides to HRV for runners on Marathon Handbook:

https://marathonhandbook.com/heart-rate-variability-guide/

00:00 3 things I learned

01:54 What does HRV measure

05:50 RHR vs HRV

07:50 Why everyone's HRV is different

09:45 What runners can use HRV for

11:10 Other ways to increase HRV

12:50 How to reliably measure HRV

15:18 Sleeping vs awake HRV

18:25 Best devices for measuring HRV

20:00 limits of HRV reporting

23:38 Future / tech limits of HRV interpretation

25:12 Winter lowers HRV

29:12 how Marco uses HRV in his run training

32:36 Marathon / ultramarathon recovery using HRV