Dr. Keith Baar is a professor at the University of California, Davis, in the Department of Physiology and Membrane Biology.
During his PhD studies, his research revealed that mechanical strain on muscle fibers activates the mammalian target of rapamycin (mTOR) signaling pathway, a crucial regulator of muscular hypertrophy.
Subsequently, he studied the molecular dynamics of skeletal muscle adaptation to endurance training under the guidance of Dr. John Holloszy, a legend in the field of exercise physiology, considered the father of modern exercise biochemistry.
Building on all of this experience, he conducted research into tendon health and the potential for engineering ligaments, which could have implications for treatment and recovery from injuries.
Dr. Baar now runs the Functional Molecular Biology Lab at UC Davis. His lab’s work ranges from studying molecular changes in our cells to conducting studies to effect real-world improvements in people’s health, longevity, and quality of life.
Please enjoy!
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Want to hear another episode that explores the possibilities of rapamycin? Have a listen to the conversation I had with Peter Attia, David M. Sabatini, and Navdeep S. Chandel at the source of this miraculous compound: Easter Island. Here, we discuss how one of the most important discoveries of medical science was almost lost, why metabolism (along with longevity) research is key to treating a long list of diseases, intermittent dosing of rapamycin, parenting advice from scientists on confidence and conflict, the necessary failures of good science, good fonts versus bad fonts, “non-potato” relationships, and much more.
What was your favorite quote or lesson from this episode? Please let me know in the comments.
SELECTED LINKS FROM THE EPISODE
- Connect with Dr. Keith Baar:
The transcript of this episode can be found here. Transcripts of all episodes can be found here.
Physiology & Biology
Strength Physiology
- Muscle Hypertrophy
- Force Transfer
- Connective Tissue Adaptation
- Tendon vs. Ligament
- Stress Shielding
- Collagen Synthesis
- Lysyl Oxidase (LOX)
- Mitochondrial Biogenesis
- Mitochondrial Function
- Mitophagy
- Refractory Period
- Minimum Effective Dose
- Systemic Inflammation
Molecular Biology
- mTOR (Mechanistic Target of Rapamycin)
- IGF-1 (Insulin-Like Growth Factor 1)
- Growth Hormone Receptor
- JAK-STAT Pathway (Janus Kinase-Signal Transducer and Activator of Transcription)
- Super Amino Acids: Glycine and Proline
- Ketones/Ketogenesis
- PGC1-Alpha
- Reactive Oxygen Species (ROS)
Exercise Physiology
- Isometric Contractions (Yielding vs. Overcoming)
- Eccentric vs. Concentric Contractions
- Rate of Perceived Exertion (RPE)
- Load Duration
- Rest Intervals
- Jerk
- Tempo
- Static vs. Dynamic Stretching
Injury & Recovery
- Tendinopathy
- Alfredson Protocol
- Scar Tissue Formation
- Anterior Cruciate Ligament (ACL) Rupture/Repair
- RICE (Rest, Ice, Compression, Elevation)
- Immobilization
- Pain Management
- Debridement
Training & Rehabilitation Methods
- Shockwave Therapy
- Hangboard Training
- Isometric Holds
- The Alphabet Exercise
- Eccentric Loading
- Strength Training
- Thera-Band Flexbar
Substances & Interventions
Supplements
Pharmaceuticals
- Rapamycin
- Metformin
- JAK-STAT Inhibitors (ending in -NIB, e.g., Itacitinib, Vorasidenib)
- Fluoroquinolone Antibiotics (e.g., Ciprofloxacin)
- AT1 Receptor Drugs (Sartan drugs)
- Resorbable vs. Non-Resorbable Sutures
- Testosterone
- Estrogen
- Nandrolone
- Liothyronine (Cytomel)
- Relaxin
Orthobiologics (Critiqued)
- BPC-157
- PRP (Platelet-Rich Plasma)
- Prolotherapy
- Stem Cells
Diets
Institutions & Places
- The UK Sports Institute
- Rapa Nui (Easter Island)
- UC Davis
- Aspetar
- Finland
- University of Illinois, Chicago
- Maastricht
- NFL
- NCAA
Movies
Research
- Minimizing Injury and Maximizing Return to Play: Lessons from Engineered Ligaments | Sports Medicine
- Acute Resistance Exercise Activates Rapamycin-Sensitive and -Insensitive Mechanisms That Control Translational Activity and Capacity in Skeletal Muscle | Journal of Physiology
- Effects of Stress Shielding on the Mechanical Properties of Rabbit Patellar Tendon | Journal of Biomechanical Engineering
- A 1-Month Ketogenic Diet Increased Mitochondrial Mass in Red Gastrocnemius Muscle, but Not in the Brain or Liver of Middle-Aged Mice | Nutrients
- Ingestion of a Whey Plus Collagen Protein Blend Increases Myofibrillar and Muscle Connective Protein Synthesis Rates | Medicine & Science in Sports & Exercise
- Pentadecapeptide BPC 157 Enhances the Growth Hormone Receptor Expression in Tendon Fibroblasts | Molecules
- ACE-II Receptor Antagonists Are Associated with Achilles Tendon Rupture | University of Eastern Finland
- Effect of Estrogen on Musculoskeletal Performance and Injury Risk | Frontiers in Physiology
- Ketogenic Diets and Mitochondrial Function: Benefits for Aging But Not for Athletes | Exercise and Sport Sciences Reviews
- Do Inflammatory Cells Influence Skeletal Muscle Hypertrophy? | Frontiers in Bioscience-Elite
Relevant Resources
- Tendon and Ligament Health | SinewUS
- RE: Tim Seeks Tennis Elbow Relief | Twitter
- How this Climber Went from V0 to V15 in 5 Years | Josh Rundle
- My Life Extension Pilgrimage to Easter Island | The Tim Ferriss Show #193
- Work Medium, Play Medium | Pretty Alright Goods
- Free Weights vs. Machine Weights? Here’s How to Choose. | GoodRx
- Orthopaedics in the Dawn of Civilisation, Practices in Ancient Egypt | International Orthopaedics
- The Characteristics of Valter Longo’s “Longevity Diet” | USC Leonard Davis
SHOW NOTES
- [00:07:12] How I discovered Keith’s work through a tweet about tennis elbow and rock climbing.
- [00:07:54] Emil Abrahamsson’s hangboard training protocol.
- [00:09:20] The fundamental principles of strength training and connective tissue adaptation.
- [00:10:36] mTOR complex 1 and its role in muscle growth.
- [00:12:06] Engineered ligaments and the discovery of minimal effective doses for tendon adaptation.
- [00:13:50] The refractory period between optimal tendon loading sessions.
- [00:16:42] Rapamycin’s effects on muscle hypertrophy.
- [00:18:49] Protocols for tennis elbow rehabilitation.
- [00:20:28] Why isometrics work better than eccentrics for tendon healing.
- [00:22:14] Stress shielding and how load distribution affects tendon healing.
- [00:29:07] The misconception about eccentric loading for tendon injuries and why velocity matters.
- [00:29:58] Ideal duration for isometric holds (10-30 seconds) based on injury status.
- [00:33:50] My elbow issues and current rehab approach.
- [00:36:02] Overcoming vs. yielding isometrics and optimal loading strategies.
- [00:47:11] Dr. Barr’s movement prescription for my tennis elbow.
- [00:52:18] Loading timing post-surgery and RICE protocol criticism.
- [00:56:58] Achilles tendon rehabilitation after surgery.
- [01:00:18] Critique of orthopedic suturing techniques and recommendation for resorbable sutures.
- [01:04:02] Multiple position isometrics for tennis elbow rehabilitation.
- [01:07:26] Collagen synthesis, supplementation, and vitamin C timing.
- [01:12:59] Critique of BPC-157 and other injectable peptides for tendon healing.
- [01:18:19] Evaluation of orthobiologics’ (PRP, prolotherapy, stem cells) effectiveness.
- [01:21:37] JAK-STAT inhibitor drugs and their effects on tendon growth.
- [01:25:35] Drugs that increase risk of tendon ruptures (fluoroquinolones, AT-1 receptor drugs).
- [01:29:33] How estrogen affects tendon stiffness and injury risk in women.
- [01:32:48] Testosterone’s opposite effects on tendon compared to estrogen.
- [01:35:31] Protein intake recommendations and timing.
- [01:40:11] Ketogenic diet effects on mitochondrial biogenesis and longevity.
- [01:41:57] Comparison of ketogenic diet, low protein diet, and rapamycin for longevity.
- [01:47:19] Inflammation’s role in adaptation and when to reduce it.
- [01:51:17] Timing of ice baths relative to training for optimal recovery.
- [01:52:33] Parting thoughts.
MORE DR. KEITH BAAR QUOTES FROM THE INTERVIEW
“The number one cost to the US medical system is actually musculoskeletal sprains, strains, and tears—the back and the neck as well as the rest of the body. It’s more than diabetes and heart disease combined.”
— Dr. Keith Baar
“If passive flexibility were really important for decreasing tendon injury, then the women’s gymnasts who have the most passive flexibility wouldn’t be the NCAA sport with the highest rate of Achilles tendon rupture.”
— Dr. Keith Baar
“Injury related to flexibility is a U-shaped curve. So our injuries are really high when we’re very inflexible. When we get into that sweet spot where we have good mobility, we can do the full range of motion, actually the injury rate is very low. If we become hyper-mobile, we actually have that injury rate go up as well.”
— Dr. Keith Baar
“We don’t use a ketogenic diet if we want to go fast, but if we’re training for life, we see that it increases longevity, that the ketones themselves are really good for brain function.”
— Dr. Keith Baar
“The first recorded immobilizer for an ankle or a leg is from Egyptian hieroglyphs, where they showed pictures 4,500 years ago. If I took you and you said you had cancer, you would not want a treatment that was developed 4,500 years ago. You would hope that something new had been developed in the last 4,500 years. That is where we are for our orthopedic situations.”
— Dr. Keith Baar
“The reality is that there are especially certain athletes like climbers where they’re doing all kinds of heavy lifts, they’re doing all kinds of heavy work, they’re doing all kinds of really dynamic moves. And what happens, what breaks down, is they break down in their finger tendons and they break down in the little pulleys within the tendons.”
— Dr. Keith Baar
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Thank you for another stellar interview Tim. Dr. Baar is a rock star…..
My favorite quote of this interview is “We don’t use a ketogenic diet if we want to go fast, but if we’re training for life, we see that it increases longevity, that the ketones themselves are really good for brain function.”
— Dr. Keith Baar
What that quote means to me personally is “If you are a senior and you want to maintain good brain function you should do a lot of exercising including resistance and cardio however if you find for whatever reason that you cannot exercise for various purposes such as schedule, weather, sickness, etc…. then you should be on a ketogenic diet for good brain function”. If this is heirarchial then exercise tops ketogenic diet.
Excellent podcast. I have been doing overcoming isometrics exclusively for about 3 years (via straps from World Fit or high end machines at OsteoStrong) and it has been a game changer for me.
Phenomenal interview. So many great quotes and such great information, but the one quote that made me laugh out loud was your, “It’s a party.”, when referring to your elbow issues.
I’m seeing the article abstract by Timo Nyyssönen regarding ARB and achilles rupture but am not seeing if other confounding medication was taken (statins/quinolones). The other articles I’m finding, although animal trials, are showing the opposite effect. Very interesting and confusing.
This interview was exactly what I was needing right now, thank you very much!
I’d be very interested in a book by Dr. Baar combining all his knowledge and experience as well as his overall protocols regarding diet, exercises, etc.