In this entry of the Athlete Development Journal, Dr. Zach Guiser helps you train your mind, build your body, and fuel your soul.

First, he tackles Training Your Mind by arguing that robust athletic development from ages 0–18 is more valuable than a massive trust fund. He explains the concept of the "Don't Screw It Up Years" (starting around age 25) and why building a strong physical base early in life makes it infinitely easier to maintain health later on, thanks to muscle memory and nuclei retention .

Next, he dives into Building Your Body by exposing a common lie in physical therapy: the 90% Limb Symmetry Index (LSI). He breaks down why aiming for 90% of your non-injured leg is often a trap—especially if your "healthy" leg has gotten weaker during recovery . He explains why you must aim to be stronger than your pre-injury self, not just symmetrical to a de-conditioned limb .

Finally, he Fuels Your Soul with a perspective on duality: you cannot truly know joy, light, or energy without first experiencing despair, darkness, and exhaustion .

Everything in these newsletters, podcasts, social media, and on our website is for educational purposes only and should not be taken as medical advice for you or your athlete. Consult directly with a healthcare professional.

IN THIS EPISODE:

• • 00:00 - Introduction

  • 00:18 - Train Your Mind: Why Athlete Development is Worth More Than a Trust Fund

  • 02:06 - The "Don't Screw It Up Years" (Age 25+)

  • 03:07 - Build Your Body: The Lie Your Physical Therapist Is Telling You (The 90% Barrier)

  • 03:28 - What is the Limb Symmetry Index (LSI)?

  • 04:26 - Why 90% of a Weak Leg is "A Smiling Pile of Poop"

  • 05:42 - Fuel Your Soul: Why You Can't Know Joy Without Despair