Clients often present with what they call “tight muscles” which usually means the muscles are short and overactive and need to be lengthened and calmed down. I also frequently get requests to help clients “improve flexibility”. In both of these scenarios, clients might be confusing flexibility with mobility; and truly the latter makes the difference in activities of daily living as well as the gym. Learn about Functional Range Conditioning, and how building this system into traditional workouts can help clients make a profound and positive difference!

Turn Passive into Active and Accessible

Functional Range Conditioning, a science-based training protocol developed by Dr. Andreo Spina, aims to help clients acquire and/or maintain functional mobility. In this particular series of exercises, mobility refers to an individual’s range of active and usable motion. Personal trainers always seek to help clients not only maximize their movement abilities but do so safely; with FRC, we can help clients cultivate control even at those difficult-to-access end ranges of motion surrounding a joint. Slowly and methodically, this practice turns passive range of motion into active, usable movement patterns, or mobility.

Body Control

FRC excels at improving load capacity in the joints, a key factor in activities of daily life as well as any sport-related movements. By learning to enact body control (also referred to as neurological control), athletes can greatly reduce their injury risks. In order to perfect this system, we must understand how to harness the principles of both specificity and progressive adaptation.

By gradually adding to the load of any exercise or movement, muscle tissue adapts to the point where it can slowly tolerate more weight. Proceeding only at a pace within a client’s relative comfort zone, systematic overload eventually leads to better tolerance. Specificity, working in conjunction with progressive overload, reflects how adaptation of a particular muscle tissue relies on a particular type of demand. The unique demands of FRC aim at liberating movement, and accomplish this with isometric moves… and a great deal of patience.

CARs and the Brain

An important aspect of FRC includes controlled articular rotations, also known as CARs, or movement occurring at the very outer limits of a joint. Unlike flexibility training, which utilizes a more passive approach toward improvement, Functional Range Conditioning relies on isometrics and tension.

In the absence of a full range of motion, the brain senses pain/short muscles and actually inhibits mobility. Before allowing a body to risk major injury, the brain signals us to cease the pain-inducing movement, perceiving it as a direct path to injury. FRC came about as a way to progressively train the brain to release this protective grip.


[sc name=”stretching” ][/sc]


The Degree of Potential

Dr. Spina often makes reference to his rule of 10-15 degrees, in which a body typically possesses an additional 10-15 degrees of ROM, yet the brain impedes access as a built-in safety mechanism. By engaging in purposeful isometric movements, one can gradually override this neurological “hold”, thereby increasing usable mobility even at these difficult-to-reach end ranges.


Kinstretch refers to a system of precise movements which encourage the body to access/mobilize/utilize greater range of motion around joints. Furthermore, it neurologically “teaches” the brain how to safely accomplish this.

Trainers often begin a client’s session with active rather than passive stretching, thereby warming the muscle tissue in an effort to thwart any potential tearing. Passive stretching proves more effective at the end of a workout. In observing a Kinstretch class, one may notice what seems like passive stretches at the onset; however, these series of movements create tension in their wake. As Dr. Spina tells us, “Kinstretch is what you do first to prepare yourself for whatever it is that you want to do.”

Putting Science into Practice

Prior to taking clients through the Kinstretch process, trainers might want to consider participating in a few classes. The utilization of isometric tension to master mobility at the end ranges of joints, an entirely novel way of approaching the body, plunges right away into what some describe as grueling positions. After all, re-training the brain to override sticking points without incurring injury requires a great deal of muscle recruitment, and isometric tension applied for an extended period of time meets this need perfectly.

Dr. Spina utilizes terms such as Progressive Angular Isometric Loading and Regressive Angular Isometric Loading to describe how he accomplishes his principles of a body’s movement. In traditional strength training, we help clients break down and rebuild muscle tissue.

However, rather than cultivating strength and size of lean muscle mass, Kinstretch provides the opportunity to fine-tune one’s ROM in an effort to make resistance training more effective. Consider the process of training a client with sport-specific needs.

If this athlete feels his baseball swing requires more power, instead of loading weight onto shoulder and arm exercises, for example, we might “teach” his body to cultivate an increased range of motion around the shoulder joint itself. In the process of accessing and re-training the hardest-to-reach joint areas, a client gains the ability to enhance each and every challenging lift/press/squat. Once sticking points get unlocked, the improved range of motion ultimately facilitates a greater depth of muscle movement. In our baseball example, the athlete starts to notice an improvement in the power of his swing.

One team of scientists took an in-depth look at the effects of full versus partial ROM resistance training exercises, specifically addressing functional movement adaptation. The data revealed that, as we would expect, possessing a complete range of motion facilitates both hypertrophy and strength development. Those subjects who utilized only partial range of motion capabilities fell short on functional adaptations.

New Movement, New Life

Dr. Spina helped to illustrate the differences between flexibility and functional mobility, and how to harness one’s maximum ROM in order to live a full and active life. While most trainers have yet to introduce Kinstretch and FRC into traditional training programs, we can now see the importance of learning the specifics of this system and utilizing this process to further clients’ abilities and goals.


[sc name=”resistance” ][/sc]



Cathleen Kronemer

Cathleen Kronemer is an NFPT CEC writer and a member of the NFPT Certification Council Board. Cathleen is an AFAA-Certified Group Exercise Instructor, NSCA-Certified Personal Trainer, ACE-Certified Health Coach, former competitive bodybuilder and freelance writer. She is employed at the Jewish Community Center in St. Louis, MO. Cathleen has been involved in the fitness industry for over three decades. Feel free to contact her at She welcomes your feedback and your comments!