Secondary Logo

Journal Logo



Stenger, Leslie M.S.

Author Information
ACSM's Health & Fitness Journal 22(6):p 35-43, 11/12 2018. | DOI: 10.1249/FIT.0000000000000439
  • Free



Ask five health and fitness professionals to define functional training, and it is very likely you’ll get five distinct and different definitions. Chances are there’ll be some similarities, yet at the same time some interesting differences. How can that be? Think about the factors that influence your response when you are asked the question, “What is functional training?” It is one of the most misunderstood terms in the industry, and the reason is simple. The term functional training originated in sports medicine and, more specifically, in rehabilitation clinics. Early definitions focused on rehabilitation to enhance or develop the skills associated with activities of daily living (ADLs) and, frequently, when working with older adults (1,2). Functional training then moved into the coaching arena through athletic training and followed into training facilities where athletes and average individuals were exposed to a plethora of methods associated with functional training. According to DaSilva-Grigoletto et al., functionality from the perspective of the physical therapist is based on a prescription of neuromuscular conditioning aimed at the development and maintenance of ADLs (3). In this context, the desired outcome is rehabilitative in nature to restore function. Strength and conditioning coaches working with athletes use the term to reflect the type of programming that will enhance sport performance. Personal trainers working with clients use the concept to reflect a variety of outcomes such as enhanced movement patterns, motor skills, occupational skill, or improvement in one or more fitness components (strength, cardiorespiratory, flexibility, muscular endurance). The development of a functional training program starts by defining the desired outcome of the program rather than developing a program based upon a packaged fitness assessment. This unique way of looking at a concept requires the health and fitness professional to look at programming from a backward design, which will be discussed later. Your perception (i.e., your experience, knowledge, and education) and your specialization (i.e., personal trainer, exercise specialist, coach, etc.) usually dictate your answer to the question “what is functional training?” No doubt, your perception is the lens through which you view the concept of functional training. Two fitness professionals could watch an individual perform a functional training exercise and “see” the performance outcome differently, a perspective based on their own experiences. These two factors, experience and specialization, influence how functional training is individually defined.

There are two factors that influence your response when you are asked to define functional training: your perception, which results from experience, knowledge, and education, and your own specialization in the field.

Specialization influences the desired outcome of a field that has been divided into three professions: strength and conditioning, personal training, and physical therapy. These three professions have merged into what is now referred to as a performance specialist.

A performance specialist offers services to individuals that participate in active occupations such as the military, firefighters, police, emergency medical personnel, etc. Functional training aligns with active occupations that can benefit from training that is specific to the skills that transfer to theefficient movement patterns associated withthe specific job.



Each year since 2007, ACSM has conducted a worldwide survey of health and fitness professionals to determine the top fitness trends for the year. A summary of the survey results has been published in ACSM’s Health & Fitness Journal® for each of the past 12 years. Functional training has appeared in the top 10 trends in 9 of the 12 years and in the top 20 all 12 years. For the purposes of the survey, functional training is defined as using strength training to improve balance, coordination, force, power, and endurance to enhance one’s ability to perform ADLs (4).

Over the years, functional training has been expressed in a variety of ways, and it is beneficial to review some of the definitions from professionals who have spent their careers in the health and fitness industry. The professionals I chose to highlight in this article have a wealth of experience and knowledge in the health and fitness field. You’ll note that their area of specialization may influence their own individual lens and definition of functional training as depicted in Table 1 and Table 1a.

Functional Training From Key Health and Fitness Professionals
Common Reference to Functional Training

After reviewing a multitude of definitions for functional training, the most simplistic and intuitive is described by noted strength and conditioning coach Mike Boyle as “Function is, essentially purpose. Functional training can therefore be described as purposeful learning” (1). What separates functional training from other forms of training is that it is individualized, and the general outcome is improved movement. The following is a list of common themes associated with functional training:

  • Purpose-driven
  • Intentional
  • Multiplanar/Multijoint
  • Real-life activities
  • Specific
  • Task-driven
  • Injury prevention
  • Chain reaction with body
  • Individualized program
  • Integration
  • Real-life activities

The terms functional training and functional fitness are frequently used interchangeably, yet the terms training and fitness are not the same. Merriam-Webster defines fitness as “the condition of being physically fit and healthy or the quality of being suitable to fulfill a particular role or task.” Whereas, training is defined as “the skill, knowledge, or experience acquired by one that trains” (5). That leaves us with the term functional, which is defined as “something used to contribute to the development or maintenance of a larger whole.” Prominent sports scientist and biomechanist, Mel Siff, defines functionality as the following:

“Functionality depends not only on the exercise itself but on many other factors, such as the pattern of execution, the characteristics of the athlete, reps, and sets, the manner of execution, the phase of training, interaction with other training, the current physical and mental state of the athlete, the overall training program, and several other variables” (6).

Over the course of time, there have been many derivatives of the term functional training. Many definitions are used synonymously because there are common terms and ideas within the definitions as reviewed in Table 2.

Synonymous and Misinterpreted Terms

There are two other terms that have very distinct definitions and should not be used interchangeably with functional training: corrective exercise and sport-specific training. Eric D’Agati, a Functional Movement Systems trainer, describes the difference by explaining corrective exercises as being designed to correct an imbalance or dysfunction found in a movement. Whereas, functional exercises reinforce the movement once the corrective exercise has been applied (7). Mike Boyle describes sports-specific training as activities that often mimic the exact skill associated with the sport. It may incorporate exercises that are general in nature but will be used through participation in the sport (1). The goal of functional training is not to mimic movement requirements of sport, such as the serve in tennis. Instead, the focus is to train the various movement patterns that will enhance the specific skills associated with the tennis serve such as rotation through multiple planes.




Specialization influences the desired outcome of a field that has been divided into three professions: strength and conditioning, personal training, and physical therapy. According to Mike Boyle, the three specializations, to some degree, have merged into what is now referred to as performance development or enhancement, and the professionals are now known as performance specialists (1). In many instances, these performance specialists will offer services to individuals that participate in active occupations such as the military, firefighters, police, and emergency medical personnel. Functional training aligns with active occupations that can benefit from training that is specific to the skills that transfer to the efficient movement patterns associated with the specific job. This specialized type of training is referred to as tactical training. The National Strength and Conditioning Association (NSCA) offers educational courses and a Tactical Strength and Conditioning Facilitator program. The American Council on Exercise and the National Federation of Professional Trainers both offer specialization courses and certification specific to functional training.


The current body of research focusing on functional training reflects a vast array of exercise options with varying designs, focus, and outcomes; however, there is very little research specific to functional training as a training program. The reason stems from the fact that functional training is a very individualized program, and no one program can address the general population. This concept was confirmed in the ACSM Position Stand produced in 2011 (8). One purpose of the paper was to provide detailed evidence-based recommendations to improve physical fitness parameters to improve general health. A table was created to provide specific recommendations and studies that represent evidence-based research supporting recommendations for cardiorespiratory exercise, resistance training, and neuromotor exercise training. There are very specific recommendations for program development of cardiorespiratory exercise and resistance training but very few studies that have evaluated the benefits of neuromotor exercise training, especially in younger adults. Therefore, the recommendations are stated as “unknown” for volume, pattern, and progression of neuromotor or functional training.


Traditional progressive resistance training focuses on increasing load/weight in a gradual manner with the purpose of strengthening major muscle groups often for performance and/or aesthetics. On the other hand, functional training focuses on enhancing the quality of movement through training specific skills associated with movement. Figure 1 demonstrates common differences between traditional and functional training.

Figure 1:
Traditional training compared with functional training.

ACSM refers to functional training as neuromotor training and defines it as training that incorporates motor skills such as balance, coordination, gait, agility, and proprioceptive training (8). Chiung-ju et al. describe functional training in a similar manner. They view the concept as an attempt to train muscles in coordinated, multiplanar movement patterns and incorporate multiple joints, dynamic task, and consistent alterations in the base of support for improved function (9). The link between traditional and functional training is displayed within the evidence-based principles. Three common principles are associated with resistance training: progressive overload, variation, and specificity (10–13). Progressive overload connotes a gradual increase in load placed upon the body during training over time. Variation, also referred to as periodization, reflects a systematic manipulation of acute program variables over time to promote various physical adaptations to the training. Specificity refers to designing the program and selecting the exercises that will result in a specific adaptation to a specific stimulus and is referred to as the SAID principle or Specific Adaptation to Imposed Demands. The principle most closely associated with functional training is specificity of training (SAID principle). Nick Tumminello, NSCA’s 2016 personal trainer of the year, explains that training for specificity focuses on improving specific adaptations that transfer into target movements. Training using squat variations to improve vertical (squat) jump height is an example of a specific exercise (13). Gray describes the concept as “applied functional science” (14). In clear terms, the principle of specificity explains the need to develop a program based on the defined outcome (15–17). Gary Gray is a respected physical therapist and is often referred to as the “Father of Function.” Gray’s concept of “applied functional science” focuses on the quality of movement in developing a training program, a major paradigm shift in how training and exercise are perceived (18).

“Applied Functional Science is the convergence of Physical Sciences, Biological Sciences, and Behavioral Sciences that consists of the Principles-Strategies-Techniques process for functional assessment, training and conditioning, rehabilitation, and injury prevention that is practical for any and all individuals regardless of age or ability” (14).

Movement Literacy as an Art

Movement literacy implies that the health and fitness professional not only has the theoretical knowledge of the body as a biological system but also understands how biology influences physical action and, finally, how to instruct the client, patient, and/or athlete to achieve the desired outcome. Simply put, training functionally requires the body and mind to work together to link efficient movement patterns resulting in the defined outcome/goal. This places the burden on the health and fitness professional to assure that link occurs and requires a specific level of rapport between the health and fitness professional and client, patient, and/or athlete (12,14,19). Gray Cook, physical therapist and co-creator of the Functional Movement Screen (FMS), describes this concept as movement literacy, the ability to read and write movement patterns (20). This requires the professional to understand human movement within the body and how to develop programs to address specific movement patterns with a major focus on the importance of instruction for efficient movement to occur. Instruction addresses the ability of the health and fitness professional to convey the information in a way that each patient, client, and athlete can understand how it will benefit them on a personal level. This ability to personalize instruction is referred to as the “art” of the profession. Nobel-prize winning physicist, Richard Feynman, explains that the key to success as an instructor “is to be able to explain the most complex ideas in the simplest terms” (21). For example, agility is an important secondary fitness component for all individuals and an experienced health and fitness professional (instructor) will be able to define how agility is important to each patient, client, and athlete. An older client may need to enhance agility to be able to play with their grandchildren, whereas a basketball player needs this skill to effectively defend their opponent or control the ball on offense.



When a professional is presented with a concept that is broad, confusing, and often misunderstood, it is helpful for him/her to establish a pathway that provides a framework for defining and describing the topic as it relates to program development. In very general terms, functional training refers to an outcome-based program that may include a variety of training styles that are performed with a purpose to enhance specific movements, related to ADLs, and/or sport-recreational skills. The common denominator in a functional training program is simple; that is, the outcome defines the program. So, in essence, the health and fitness professional must first define the desired outcome and then program to achieve it. It may sound simple, but it is not; to develop a functional training program, one must be able to integrate knowledge from a variety of the movement sciences such as anatomy and functional anatomy, motor behavior, applied biomechanics, exercise physiology, and human behavior. To avoid confusion, always remember, it is critical to start with defining the desired outcome, followed by an analysis of the movement patterns and muscle groups that support the outcome. Specific exercises are not “functional” in nature, but a program designed to achieve a specific outcome can be termed a “functional” training program.

Functional training is simple to understand on paper but complicated to implement. To this day, there are no universally accepted methods for how to train functionally. Health and fitness professionals must use their individual experiences and client feedback to decide the specific training method to bring about the desired outcome for participants.

In general, fitness program development is based on the application of PRINCIPLES that represent the scientific evidence necessary to select the most appropriate STRATEGIES that will lead to choosing specific TECHNIQUES or movements that address the desired outcome (14). The principles, strategies, and techniques should not be viewed as isolated units. Knowing how to apply the appropriate principles, strategies, and techniques to create a functional program for participants is the “art” of functional training. Therefore, functional training is an integrated approach that involves becoming aware of the role the entire body plays relative to efficient movement. Being able to move efficiently is a central theme throughout our lives. Human movement can be viewed on a continuum from being less functional to more functional based on the ability to move efficiently. The following progression model developed by Kennedy and Yoke is one example that could be helpful in creating functional movement program design insights. They developed this for fitness professionals to help them organize movement progressions in a systematic order represented by levels that could be viewed on a continuum similar to Figure 2. See Table 3 for a description of each level (2,22).

Figure 2:
Functional training considerations (A,B,C,D).
Progression Levels

Another helpful option is the FMS initially developed by Gray Cook and Lee Burton for athletes. Visit the YouTube video on “What is Functional Movement Screening” if you are not familiar with the FMS testing system (https://www.youtube.com/watch?v=p5yqSZaz4ms). The FMS is a predictive system consisting of seven steps to rank movement patterns basic to efficient movement and function (23). Once a general ranking has been established, the next step is to develop an individualized program that will address the physical needs and also the desired outcome of the patient, client, and athlete as defined by the health and fitness professional. A functional training program applies the most appropriate training methods that specifically address the movements associated with the planned outcome. This philosophy requires a backward logic in program design as illustrated in Figure 3.

Figure 3:
Functional training program development.
  1. One must start with a defined outcome. Development of the outcome/goal is based on critical factors such as the following:
    • ο The physical and behavioral abilities of the client, patient, and athlete based on a variety of assessments.
    • ο The desired outcome that has been established between the health and fitness professional and the client, patient, and athlete.
  2. The health and fitness professional analyzes the screening information, the assessment results, and the desires of the patient, client, and athlete to develop the most appropriate training methods.
    • ο Those training methods should promote the enhancement of specific body system(s) defined in the outcome, based on the principles and most effective strategies for the defined outcome/goal.
    • ο Program implementation is based on the most appropriate techniques or individual exercises that will ensure the patient, client, and athlete can achieve the defined outcome/goal.


Many of the general strength training programs using individual muscle groups and exercises do not apply because functional training programs are unique and individualized for a specific person(s) with a purposeful goal. For example, a client is interested in purchasing a horse that will stay on the property rather than a stable. This client needs to develop appropriate strength to perform daily tasks such as move bales of hay and pick up buckets of water. These activities require overall body strength through movements in multiple planes. Kettlebell exercises would be more effective than isolated exercises on machines. Progression occurs on a continuum and is a critical aspect of program design; however, progressions are based on skills associated with the desired movement patterns rather than any one skill as illustrated in Figure 2. According to ACSM, progressions for traditional resistance training are defined as “the act of moving forward or advancing toward a specific goal over time until the target has been achieved for the trainable characteristics of muscular strength, power, hypertrophy, and local muscular endurance” (15). Figure 3 depicts a variety of progression continuums that assist in understanding the thought process of applying functional training principals to program from other professionals in the field.


Functional training is a mysterious philosophy of training because of its many definitions and inconsistent implementations. Yet, in the purest form, functional training is a dynamic concept that is rooted in the improvement of movement and can be adapted for any individual. The improvement of movement can and will be interpreted differently among health and fitness professionals. Each functional training program can be individualized with a focus on integrating movement patterns to achieve a defined outcome/goal. At its very best, functional training is fluid in nature and enables the professional to be creative and apply his/her knowledge, education, and experience to help each patient, client, and athlete with whom they have the privilege to work. So, go ahead and apply your interpretation of functional training into your programming and see what you come up with!


Functional training requires the body and mind to work together to link efficient and purposeful movement patterns resulting in a defined outcome/goal. Creating that link is the responsibility of the health and fitness professional and requires a specific level of rapport and trust between the health and fitness professional and the client, patient, and athlete. Health and fitness professionals need to understand human movement, how to develop programs, and how to instruct individuals to promote efficient and purposeful movement for the client, patient, and athlete.


1. Boyle M. New Functional Training for Sports. Champaign (IL): Human Kinetics; 2014.
2. Kennedy-Armbruster C, Yoke MM. Methods of Group Exercise Instruction. 3rd ed. Human Kinetics: Champaign (IL); 2014.
3. DaSilva-Grigoletto M, Brito C, Heredia J. Functional training: functional for what and for whom? Revista Brasiteriade Cineanthropom Desempentro Humano. 2014;16(6):714–9.
4. Thompson W. Worldwide survey of fitness trends for 2018. ACSMs Health Fit J. 2017;21(6):10–9.
5. Merriam-Webster Dictionary. [Internet]. [cited 2018 Jun 19]. Available from: https://www.merriam-webster.com/dictionary/literate
6. Siff MC. Functional training revisited. NSCA Strength Cond J. 2002;24(5):42–6.
7. D'Agati E. Functional vs corrective exercise: Anthony D'Agati. [Pod Cast: cited 2015 July 8]. Available from: https://www.functionalmovement.com/Articles/611/functional_vs._corrective_exercises
8. American College of Sports Medicine. Position Stand: quantity and quality of exercise for developing cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc. 2011;43(7):1334–59.
9. Chiung-ju L, Shiroy DM, Jones LY, Clark DO. Systematic review of functional training on muscle strength, physical functioning, and activities of daily living in older adults. Eur Rev Aging Phys A. 2014;11(2):95–106.
10. Bruscia G. The Functional Training Bible. Aachen (Germany): Meyer & Meyer Sport; 2015.
11. Hawley JA. Specificity of training adaptation: time for a rethink? J Physiol. 2008;586:1–2.
12. Siff M, Verkhoshansky Y. Supertraining. 6th ed. Rome, Italy: Verkhoshansky Publishing; 2009.
13. Tumminello N. Functional training: separating the sense from nonsense. [Internet]. [cited 2018 Aug 1]. Available from: http://nicktumminello.com/2014/09/functional-training-separating-the-sense-from-nonsense/
14. Gray G. Functional training defined. IDEA Health & Fitness [internet]. [cited 2018 Aug 1]. Available from: http://www.ideafit.com/fitness-library/functional-training-defined
15. American College of Sports Medicine. Position Stand: progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687–708.
16. Reilly T, Morris T, Whyte G. The specificity of training prescription and physiological assessment: a review. J Sports Sci. 2009;27:575–89.
17. Haff GG, Triplett TN. Essentials of Strength Training and Conditioning. 4th ed. Human Kinetics: Champaign (IL); 2016.
18. Scordino J. Applied functional science [Internet]. [cited 2018 Aug 1]. Available from: https://www.grayinstitute.com/videos/article-details/340/movement-literacy
19. Cook G. Athletic Body in Balance. Champaign (IL): Human Kinetics; 2003.
20. Cook G. Movement Literacy. [Internet]. [cited 2018 Aug 1]. Available from: https://www.otpbooks.com/gray-cook-movement-literacy/
21. Feynman RP. Surely You're Joking, Mr. Feynman. Ashland (OR): Blackstone Audiobooks; 1997.
22. Kennedy CA. Functional exercise progression. IDEA Personal Fitness Trainer [Internet]. 2003. [cited 2018 Aug 1]. Available from: http://www.ideafit.com/fitness-library/functional-exerc-ise-progression
23. Cook G. Movement: Functional Movement Systems. Santa Cruz (CA): On Target Publications; 2010.
24. Chek P. Functional training: what, when, why, how and where to do it [Internet]. [cited 2018 Aug 1]. Available from: http://www.ppssuccess.com/FoodforThought/ArticlesbyPaul/ArticlesbyPaulChekDetailPage/tabid/496/smid/2144/ArticleID/42/reftab/104/Default.aspx
    25. Chek P. What is functional exercise? [Internet]. [cited 2018 Aug 1]. Available from: http://www.ptonthenet.com/content/articleprint.aspx?
      26. Gambetta V. Athletic Development: The Art & Science of Functional Sports Conditioning. Champaign (IL): Human Kinetics; 2007.
        27. Santana JC. Functional Training. Champaign (IL): Human Kinetics; 2016.

          Recommended Readings:

          • Bruscia G. The Functional Training Bible. Aachen (Germany): Meyer & Meyer Sport; 2015.
          • Boyle M. New Functional training for Sports. Champaign (IL): Human Kinetics; 2016.
          • Cook G. Movement: Functional Movement Systems. Santa Cruz (CA): On Target Publications; 2010.
          • Cook G. Athletic Body in Balance. Champaign (IL): Human Kinetics; 2003.
          • Gambetta V. Athletic Development: The Art & Science of Functional Sports Conditioning. Champaign (IL): Human Kinetics; 2007.
          • Liebenson C. Functional Training Handbook. Philadelphia (PA): Lippincott Williams & Wilkins; 2014.
          • Santana JC. Functional Training. Champaign (IL): Human Kinetics; 2016.

          Web sites:


          Functional Training; Functional Movement; Functional Exercise; Integrated Movement; Purpose-Driven Training

          Copyright © 2018 by American College of Sports Medicine.