Quantity training asks how much a body can do; quality training asks what structure the body is doing it from
Chapter 6 of the Spinal Fitness book distinguishes 2 training philosophies. Quantity training focuses on more repetitions, more load, more effort and more intensity. Quality training examines how the body produces force and trains the structure to improve stability, alignment and mechanical advantage. The book's sequence rule follows from that distinction: "structure first, strength second."
Chapter 6 states that quantity training assumes larger muscles and greater output automatically produce better performance and greater resilience. Chapter 6 grants that this approach often exposes raw physical capacity, and states that it may also risk spinal stability, shorten athletic longevity and increase the likelihood of injury when the body's mechanics are not sound.
Quality training, in the book's definition, does not stop at what a movement looks like from the outside; it considers the internal interaction of joints, curves, muscles and force transmission. The book condenses the difference into 2 questions. Quantity training asks, "How much can you do?" and quality training asks, "What structure are you doing it from?" Quantity training puts people under stress and sees who survives; quality training evaluates structure, identifies mechanical disadvantage, restores alignment, and then adds load progressively.
Chapter 6 calls this the reason Spinal Fitness training is structured adaptation rather than simply exercise: it uses specific positions, supports and movements to direct force into the body in a way that promotes better spinal structure and function over time.
Chapter 6 names 2 kinds of trainer. The artist trainer evaluates 4 outward results: who jumps high, who runs fast, who lifts heavy, who looks muscular. Chapter 6 states that these 4 show what the body can do today, not what it is costing the muscles and joints to do it. The architect trainer evaluates the structure that produces the action, and the book gives that trainer 5 questions:
The book's architect reads the body as a lever system. If the fulcrum, lever arm, resistance or effort is poorly aligned, Chapter 6 states, the system cannot function efficiently regardless of how hard it works, and a strong body is created by the correct relationship between muscle, bone, joint, posture and force rather than by muscle alone.
Chapter 6 states that a stronger muscle can produce more force, and that this added force is useful only if the body has the structure to receive, direct and stabilize that force. If the spine lacks proper curvature, the joints are poorly aligned, or the body relies on compensation, added strength may increase the force traveling through a vulnerable system, so the body can generate more force than the joints can safely manage.
When the S-shaped spine is present and stable, the book states, added muscle power can be put to productive use, and muscle effort can combine with resistance into a stabilizing resultant force. Without proper spinal structure, the same muscular effort may shear through joints, increase compression, provoke guarding and accelerate fatigue. The person may feel stronger in the gym while the spine becomes less durable in life.
For people with lost curves, chronic guarding or repeated back injury, Chapter 6 sets the first goal as restoring the structure that reduces the need for compensation, not strengthening the compensation. Its definition of a strong body is the body that keeps producing force without breaking its own spinal structure to do it. Chapter 2 states the same rule for youth athletes: Spinal Fitness training is not primarily about hypertrophy or building larger muscles of effort, and strength built on poor spinal structure can reinforce compensation.
Chapter 6 states that stability depends on how the resultant force at the joint is handled. If the force travels into compression, the joint can become more stable with less muscular effort, because bone geometry carries the load. If the force travels into shear, the body must add stabilization from ligament, disc, cartilage, facet or muscle, and if those structures are weak, recovering or already damaged, the exercise creates strain in the tissue that needs protection.
The book's explanation for injuries during strengthening work follows: the movement challenges the target muscle while overwhelming the stabilizing tissue, and the person feels the muscle working and assumes the exercise is beneficial. Chapter 6 lists 4 questions a responsible program must answer for each exercise:
Chapter 5 states the same point for athletes: a strong athlete with poor spinal structure may generate large forces that increase shear and internal strain instead of creating efficient movement. Chapter 5 closes that section in 2 sentences: "The body does not need strength alone. It needs strength traveling through structure."
Chapter 6 calls the old "no pain, no gain" philosophy the most visible result of counting only the muscle. Its example is a young athlete who reports knee pain during leg curls and is told to push through because the muscle needs building. In the book's reading, that pain is the anterior cruciate ligament signaling that the stabilization demand has exceeded its capacity, and continuing the exercise accumulates damage in the tissue that must keep the joint stable for the rest of the athlete's career.
The book carries the quality-training rule into the 5-step system. Chapter 8's Trainer Application states: do not skip phases because the client is eager or strong; if a person is still bracing through Step 1, Step 2 or Step 4, they are not ready for more load; and progression in this system is earned by cleaner force transfer, not by enthusiasm. Chapter 9's dosing summary adds: start small, earn progression, and never chase more at the cost of form.
Pain, numbness, tingling and dizziness are the stop signs in the Spinal Fitness book. When one appears, stop the exercise, get evaluated, and then proceed with a therapeutic exercise program designed by a Spinal Fitness expert. The book's training rule for every step is that strain is acceptable and pain is not.
The PowerCushion is the fulcrum for the Sit-Up and the Pelvic Tilt, and the Neck and Back Shaper rolls carry the supported rest in Step 5.
Practitioner Eileen Durfee, NBS (Nutritional Balancing Science), NASM-CPT - wellness educator, inventor, author, and a Nationally Certified Spinal Fitness Specialist.
The About the Author page of the Spinal Fitness book records that Eileen has worked in the wellness industry since 2010, earning her Nutritional Balancing Science training and becoming a NASM Certified Personal Trainer, and that she has helped thousands of people in 91 countries through her products, education and one-on-one guidance.
Our Facebook group is free to join for questions about any of the 5 steps in the Spinal Fitness system.
Quantity training focuses on more repetitions, load, effort and intensity; quality training examines how the body produces force and trains the structure first.
The book states that without proper spinal structure, added strength may shear through joints, increase compression, provoke guarding and accelerate fatigue.
No. Chapter 6 states that stability depends on whether the resultant force at the joint becomes compression or shear.
Restore the S-shaped structure before adding strength, so that muscle effort combines with resistance into a stabilizing resultant force.
When the person is no longer bracing through Steps 1, 2 or 4. Progression is earned by cleaner force transfer, not by enthusiasm.
Published October 26, 2026 - Updated October 26, 2026
By Eileen Durfee, Nationally Certified Spinal Fitness Specialist, NASM-CPT, and author of the Spinal Fitness book.
More from Eileen Durfee
Eileen's free guide, Is Your Posture Aging You?, on EileenDurfee.com
