Sign Up for KinStretch June 7, 2026
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About Coach Jason
Certified Personal Trainer
Jason Harrell has spent over a decade helping people move better, feel stronger, and live more fully — and his path to doing that is unlike most coaches you'll find.
A Brooklyn-based strength and conditioning coach since 2012, Jason built his foundation training clients at Equinox, leading performance programs at Iron Lion Performance, and earning advanced certifications in Kinstretch, Functional Range Conditioning (FRCms), and Functional Range Assessment — placing him among a small group of coaches trained directly under Dr. Andreo Spina's Functional Anatomy Seminars system.
What sets Jason apart is what came next. Rather than stop at coaching, he went deeper — completing continuing education in Exercise Science with a focus on Athletic Performance and Sport Nutrition, then pursuing and completing a Master's in Occupational Therapy at Mercy University. He has worked hands-on in physical therapy clinics treating orthopedic, neurological, and post-surgical patients, served as an Anatomy and Cadaver Lab Teaching Assistant, and holds certifications in Mental Health First Aid instruction and integrative health coaching through Precision Nutrition.
The result is a coach who doesn't just program workouts — he understands how the body is built, how it breaks down, and how to bring it back. Whether you're an athlete trying to unlock performance, an active adult navigating the changes that come with midlife, or someone who simply wants to move through daily life with less pain and more ease, Jason brings clinical depth, genuine curiosity, and a straightforward coaching style that meets you where you are.
What is Kinstretch?
Comprehensive Mobility Training for Optimal Performance
Kinstretch is a movement enhancement system built on the science of joint health and mobility. Developed using methods from Functional Range Conditioning (FRC) to train your body to actively control its full range of motion — not just passively stretch into it. Every exercise targets the tissues surrounding your joints, improving their capacity to handle load, absorb stress, and move freely.
Unlike traditional stretching, Kinstretch makes your mobility functional. That means the range you develop in a session is range your body can actually use — whether you're swinging a golf club, picking up a grandchild, squatting heavy, or simply getting out of bed without stiffness.
Sports Performance
For athletes, mobility is the foundation everything else is built on. Greater range of motion means more powerful movement patterns, better force production, and a significantly reduced risk of injury. Kinstretch addresses the joints that sport demands most — hips, shoulders, spine, ankles — building the kind of supple, load-bearing mobility that translates directly to the field, court, or platform. When your joints can move freely and under control, your strength and speed have nowhere to go but up.
Quality of Life
As we age, it's not muscle we lose first — it's the ability to move through space comfortably and confidently. Kinstretch is designed to change that. By restoring healthy joint function and retraining the nervous system to own a wider range of motion, clients find that everyday movements — reaching overhead, sitting on the floor, walking long distances — become easier and less painful. It's not about being an athlete. It's about staying capable, independent, and comfortable in your own body for decades to come.
Strength and mobility are not opposites — they're partners. A muscle that can only contract in a limited range is a muscle that will always have a ceiling. Kinstretch expands that range and strengthens the tissues within it, which means deeper squats, fuller overhead positions, and more complete engagement of the muscles you're already training. Lifters who add Kinstretch to their practice consistently find they unlock movements they'd been stuck on for years — not because they got stronger, but because they finally had the joint capacity to express the strength they already had.
What My Clients Are Saying
Nafisa C
Cristina N.
Cristina N.
Jason worked with my failing middle aged body through multiple uncertain physical and mental health experiences. I went from newly diagnosed autoimmune condition to running the NYC marathon thanks to Jason's coaching
Cristina N.
Cristina N.
Cristina N.
SoI had heard about Jason from some of the other women at the gym. Then one of the owners, after hearing about the amount of pain I was in, referred me to him. They said he could help me. After going to a few 7 am classes I started seeing Jason one on one. I knew that I was in pain but thought I was hiding it pretty well. Jason immediately saw right through me. When we started working one on one he made sure to explain everything and start slow. I have a dance background and some years of athletics, but he saw all my bad habits and misalignment and started working on it joint by joint from the toes up. Now I live and move and lift with exponentially less pain. I feel stronger now than I ever did while dancing. Plus, Jason has become a good friend too.
Frank
Cristina N.
John E.
I appreciate Jason's expertise, enthusiasm and his calm direction. It's important to have somebody who knows what to do, based on my specific issues/needs. Meeting with him regularly has led to steady improvement physically and an understanding and appreciation of how the body works. In the last year, I've seen great improvement of overall mobility and strength and I'm enjoying the process.
I was looking for somebody who could give me the kind of direction and a developing program that would yield the best results without injury.
Since working with Jason, I feel confident that the workouts are doing what they need to and I've noticed a big difference in how I feel during the day. I'm feeling stronger and more confident.me other cool things someone says
John E.
John E.
John E.
Jason Has trained me for 10 years, improving my strength and mobility, and helping me recover from two hip replacement surgeries. He exhibits exceptional knowledge of anatomy and biomechanics; I often observe other trainers asking him for advice. Jason is friendly and very easy to work with, and I would recommend him to anyone.
Jaime R.
John E.
Jaime R.
Working with Jason through both my pre- and post-natal journey was one of the best investments I made for myself. He is knowledgeable, compassionate, accommodating, and incredibly steadfast in his approach. He always met me where I was physically and mentally, while still motivating me to push myself in a healthy and sustainable way.
Jason helped me build real strength and confidence throughout pregnancy, and I truly attribute a lot of my smooth and positive birth experience to the work we did together. His strength training programs are thoughtful, effective, and tailored.
Beyond the workouts themselves, Jason creates an environment that feels supportive, empowering, and judgment-free. Whether you’re brand new to training, getting back into it, or navigating major life changes like pregnancy and postpartum, he knows how to adapt and guide you in a way that feels realistic and encouraging. I can’t recommend him enough.
Contact Me
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