Rapid Fire

The Fast Lane, Episode 8: Foot Strength, Acceleration, and the Practical Side of Speed Development

Speed development can quickly become overcomplicated, but Chris Korfist and Dan Fichter bring the conversation back to what matters most: the foot, the lower leg, the nervous system, and the athlete’s ability to handle impact.  For Dan, the answer starts with the foot. If athletes cannot absorb and manage energy through the lower leg, they are going to struggle to run fast. That means foot strengthening, isometrics, acceleration work, plyometrics, altitude drops, and teaching the body how to organize itself under impact.  Chris agrees and expands on the concept by describing what he sees in his fastest athletes. While they may all look different from the side, they share a similar quality at ground contact and foot departure: the ability to roll through the foot and push off effectively through the big toe.   The conversation then moves into acceleration. Dan explains that getting into acceleration positions is not just a strength problem. It is also a neural and vestibular problem. The brain has to feel safe enough to allow the athlete to project forward, fall, and strike the ground in aggressive positions. If the nervous system does not trust the position, the athlete will find another way to move.  The second half of the episode dives into what has changed and what has stayed in Chris and Dan’s programming over the years. Dan discusses repeated short sprint bursts and how acceleration work may create a hypoxic training effect without athletes consciously thinking about breath-holding. Chris explains that his coaching life is now divided into “pre-1080” and “post-1080,” with resisted, assisted, isokinetic, and wave sprinting changing how he organizes speed training.  As the episode closes, Chris explains that his indoor season focused heavily on acceleration, while the later part of the track season shifts toward top-end speed, overspeed, technical refinement, and hip flexor work. Dan explains that his football offseason emphasizes learning how to fall, using reaches, foot activation, neural preparation, and low squat jumps to help athletes develop the qualities needed for acceleration.  The episode finishes with a discussion on technology, including the 1080 Sprint/Cable, reactive visual systems, bullet belts, resisted sprinting, and the dream of having a runway that can change grade for uphill and downhill sprint work.

Rapid Fire with Chris Korfist & Bobby Krause

In this episode, Chris Korfist sits down with Bobby Krause of Krause Performance Training in New York to talk about how he uses training technology to assess, motivate and individualize speed development for athletes ranging from middle school to high school, and beyond.  Bobby shares how tools like the ShredMill, OHM, Hawkin Dynamics force plates, Kinvent K-Power, timing systems, VBT sensors, RockDaisy and the USR platform help him better understand each athlete’s needs and make training more engaging, measurable and specific.  You can find Bobby Krause at Krause Performance Training in New York, where he specializes in speed, agility, strength, and athlete development.  * Website: Krause Performance Training (Krause Performance Training [https://www.krauseperformancetraining.com/?utm_source=chatgpt.com])  * Instagram: @krause_performance (Instagram [https://www.instagram.com/krause_performance/?utm_source=chatgpt.com])

The Fast Lane w/ Christ Korfist & Dr. Ken Clark: Unlocking Sprint Speed

In this episode of The Fast Lane, Chris Korfist sits down with sprint biomechanics expert Dr. Ken Clark to break down the science of sprint speed and what truly drives improvements in athletic performance.  Dr. Clark explains the three key qualities that underpin sprint performance, why basic sprinting and plyometrics remain essential tools, and how concepts like angular velocity, stiffness, and hip torque influence running speed.  The conversation also challenges common misconceptions in speed training and highlights research that has shaped modern sprint mechanics and performance development.  If you work with athletes who need to move faster—whether in basketball, football, track & field, or other field sports—this episode provides clear takeaways on how to prioritize training for speed.  Connect with Dr. Ken Clark  Twitter/Instagram @KenClarkSpeed

The Fast Lane: Using the 1080 Sprint in High School Track with JT Ayers

In this episode of The Fast Lane, Chris Korfist sits down with high school track coach JT Ayers to discuss how he implemented the 1080 Sprint into his training program.  JT shares how his program fundraised to purchase the device, the challenges of learning to use it with a large team, and the practical ways he integrates the technology into daily training. The conversation explores how data from the 1080 Sprint has helped JT refine acceleration training, identify technical weaknesses, and provide athletes with objective feedback.  They also discuss how technology can support coaching decisions, improve athlete buy-in, and make advanced training methods, like resisted and overspeed sprinting, both safer and more effective.  Connect with JT  On X @CoachJTAyers and Instagram @Coach_Ayers

The Fast Lane w/ Chris Korfist, Chris Kerr & Dan Fichter: The Truth About the 40-Yard Dash

Episode Overview  The 40-yard dash may be the most talked-about sprint in American sports — and the most misunderstood.  In this episode of The Fast Lane, Chris Kerr sits down with Dan Fichter and Chris Korfist to break down what truly determines elite 40-yard dash performance, why most “4.4s” aren’t real, and how force, projection, limb velocity, and nervous system readiness dictate speed far more than traditional weight-room metrics.  This conversation blends biomechanics, applied physics, neurology, and coaching reality, offering a no-nonsense look at what actually transfers to faster sprint times.  Key Topics Covered  Why Most Athletes Can’t Run a Real 4.4  * Why a 24” vertical jump or 11.5s 100m automatically disqualifies a true 4.4  * The difference between coach-timed, combine-timed, and true electronic times  * Why elite speed “looks different” the moment you see it  The Start Is Everything  * Why horizontal projection matters more than raw strength  * How poor shin angles act as a brake before the sprint even begins  * Why “crowding the line” kills acceleration  * Ideal first-step projection distance     Force, Power & Body Weight Explained (Simply)  * Force per body weight as the real limiter of acceleration  * Why elite starters cluster around ~8 N/kg  * How watts per kilogram explain why lighter athletes separate later  Neurology, Falling & Speed Permission  * Speed as a permission granted by the brain  * Why falling is a trainable skill  * How vestibular input, tendon stiffness, and threat perception affect sprinting  * Why kids who fell more growing up often end up faster  Foot, Ankle & Heel Mechanics  * Why plantarflexion is non-negotiable for acceleration  * What a “floating heel” tells you instantly  * How foot stiffness influences shin angles and projection  * Why weak feet sabotage otherwise strong athletes  Weight Room Reality Check  * Why squats and power cleans don’t guarantee speed  * When more force actually makes athletes slower  * Why positioning > load  * How bodyweight manipulation changes force-velocity profiles  Technology & Measurement  * How the 1080 Sprint changes how coaches understand speed  * Why time splits reveal more than full 40s  * Fly-10 and Fly-20 benchmarks that actually matter  * Why video + timing beats guesswork    Episode Timeline Highlights  * 0:00–10:00 – Quick-style reps, rebounds, and extreme isometrics  * 10:00–25:00 – The myth of the 4.4 & combine timing realities  * 25:00–40:00 – Force, projection, and limb velocity explained  * 40:00–55:00 – Neurology, falling, and vestibular training  * 55:00–70:00 – Indoor training solutions & first-step development  Key Coaching Takeaways  * The 40-yard dash is won before the first foot hits the ground  * Projection without limb speed creates early braking  * Athletes don’t need more force — they need better force application  * Speed training without neurology is incomplete  * If your athlete can’t fall safely, they can’t accelerate aggressively