Summary
Coach Jason Fitzgerald interviews Jay Dicharry, a physical therapist, biomechanics researcher, and author of Running Rewired, about what stability actually means and why most runners get it wrong. Dicharry explains that stability is not the same as strength -- it involves the nervous system's ability to sense body position (proprioception) and reflexively control movement during the 0.1 to 0.35 seconds each foot is on the ground per stride. The conversation centers on a critical distinction: doing squats on a stability ball looks hard but has zero transfer to running because you're never in that bilateral wobbly position while running. Real stability training for runners means building the ability to steer rotational loads from the ground through the foot, hip, and spine. Dicharry introduces a three-part stability model from researcher Punjabi -- muscles create force, the nervous system tells muscles when to fire, and joint mechanoreceptors provide spatial awareness. The key insight is that stability exercises should be simple enough for the brain to learn, then repeated until they become reflexive and stored in the brainstem.
Key Points
- Stability is not strength -- it's the nervous system's ability to reflexively control body position during dynamic movement
- Runners break down not from weak muscles but from inability to steer and stabilize joints under dynamic loads
- Squats on a stability ball have zero transfer to running -- you're never in a bilateral wobbly position while running
- The three components of stability are muscles (force), nervous system (timing), and joint mechanoreceptors (spatial awareness)
- Ground contact time during running is only 0.1 to 0.35 seconds -- stability must be reflexive, not conscious
- Driving the big toe into the ground and controlling center of pressure through the foot is fundamental to running stability
- Stability exercises should be simple enough to learn, then practiced until they become reflexive patterns stored in the brainstem
- Rate of pronation, not amount, correlates with injury risk -- it's about controlling dynamic loads
Key Moments
Runners break down from poor steering, not weak muscles
Dicharry explains that running injuries happen not because muscles are weak but because athletes can't steer and stabilize their joints under dynamic loads -- the center of pressure must travel correctly through the foot from outside edge through the big toe.
"when you start to think about what those muscles are, we're not just talking about how much you can push off. We're talking about how well you can steer and stabilize your parts as you walk and yes, run"
You can't fire a cannon from a canoe -- the three-part stability model
Dicharry describes researcher Punjabi's stability triangle: muscles create force, the nervous system tells muscles when to fire, and joint mechanoreceptors provide spatial awareness through proprioception. All three must work together.
"you can't fire a cannon from a canoe. It just doesn't work, right? The second one is you can't fly a jet engine on a paper airplane."
Stability must become reflexive -- you only have 0.3 seconds per stride
With only 0.1 to 0.35 seconds of ground contact per stride, runners can't consciously think about stability. Skills need to be practiced until they become reflexive patterns stored in the brainstem through neuroplasticity.
"the time on ground that each of you has is between 0.1, about 0.13, I mean, excuse me, 0.1 to about 0.35 seconds each and every stride, right? That's a really short period of time. You don't have time in 0.3 seconds to think about, okay, contact."
Most people make stability training too hard -- keep it simple
Dicharry warns that doing squats on stability balls looks cool on social media but has zero transfer to running. Effective stability training should challenge the nervous system at the right amount, keeping exercises simple enough for the brain to actually learn and integrate.
"a lot of people make stability training too hard. I know everybody out there has seen some picture of somebody doing squats on a stability ball. Basically, okay. Okay. It's cool. I can do them. It's fun. That has zero transfer over into running."
