Content uploaded by Kenneth J Ottenbacher
Author content
All content in this area was uploaded by Kenneth J Ottenbacher
Content may be subject to copyright.
Nullius in Verba: A Call for the Incorporation of Evidence-based
Practice Into the Discipline of Exercise Science
William E. Amonette1, Kirk L. English1, and Kenneth J. Ottenbacher2
1Preventive Medicine & Community Health, Division of Rehabilitation Sciences, University of
Texas Medical Branch
2Division of Rehabilitation Sciences, University of Texas Medical Branch
Abstract
Evidence-based practice (EBP) is a concept that was popularized in the early 1990’s by several
physicians who recognized that medical practice should be based on the best and most current
available evidence. Although this concept seems self-evident, much of medical practice was based
on outdated textbooks and oral tradition passed down in medical school. Currently, exercise
science is in a similar situation. Due to a lack of regulation within the exercise community, the
discipline of exercise science is particularly prone to bias and misinformation, as evidenced by the
plethora of available programs whose efficacy is supported by anecdote alone. In this manuscript,
we provide a description of the five steps in EBP: 1) develop a question, 2) find evidence, 3)
evaluate the evidence, 4) incorporate evidence into practice, and 5) re-evaluate the evidence.
Although objections have been raised to the EBP process, we believe that its incorporation into
exercise science will improve the credibility of our discipline and will keep exercise practitioners
and academics on the cutting edge of the most current research findings.
Beneath all physiologic phenomena lie causal mechanisms. The purpose of the scientific
process as it relates to human physiology is to uncover these mechanisms. Unfortunately,
knowledge of a phenomenon is often buried deep beneath many partially understood or even
misunderstood mechanisms rendering what we currently know incomplete. Ideally, with
each research experiment we gain a more complete understanding of a given phenomenon;
thus, knowledge is dynamic and continually evolves.
The evolution of knowledge creates a unique challenge; instructors and practitioners must
teach and practice with incomplete knowledge. Despite their best efforts to incorporate the
latest scientific evidence, by the time a lecture is delivered, it is likely that science has
already uncovered more of the story. Usually, discovery simply adds to the information that
was presented to students, but sometimes advances in knowledge radically change scientific
thought. In the 1930’s and 1940’s it was believed that muscle contractions were the result of
folding and unfolding of long protein filaments located within skeletal muscle sarcomeres.
[1] With the invention of a new, more powerful light microscope,[2] Huxley and Hanson
were able to see two proteins, actin and myosin, that appeared to slide over each other
during the shortening and lengthening of a muscle.[3,4] Now, 55 years later, the sliding
filament theory of muscle contraction is taught to all physiology students as the basis of
muscular contraction. While the teachers of the 1940’s taught to the best of their ability
Corresponding Author: William E. Amonette, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX
77555-0411, (Office) 281-283-3381, (Cell) 832-264-0492, (Fax) 281-283-3397, weamonet@utmb.edu.
The authors have no conflict of interests.
NIH Public Access
Author Manuscript
Sports Med. Author manuscript; available in PMC 2011 June 1.
Published in final edited form as:
Sports Med
. 2010 June 1; 40(6): 449–457. doi:10.2165/11531970-000000000-00000.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
based on contemporary knowledge, Huxley and Hanson’s discovery rendered what was
taught incomplete and inaccurate.
Evidence-based medicine (EBM) is a term coined in the early 1990’s to describe a paradigm
in which clinical decisions are based on the highest available levels of research knowledge
or evidence.[5,6] Although this idea seemed obvious, it was a novel approach to clinical
practice. In fact, in 2000 it was estimated that only 15–40% of clinical decisions were based
on research evidence.[7,8] The medical community’s call to evidence-based practice (EBP)
argued that knowledge is dynamic and that clinicians should incorporate the latest evidence
into practice to optimize clinical outcomes. EBP has since spread from the field of medicine
to other health fields. Much has been written about the incorporation of EBP into nursing,
[9,10] physical therapy,[11–13] and various medical disciplines including orthopedics.[14–
16]
Exercise science is susceptible to misinformation and bogus claims—perhaps more than any
other field. This is evident from a cursory knowledge of the personal training industry.
While organizations such as the National Strength & Conditioning Association (NSCA) and
the American College of Sports Medicine (ACSM) have done much to legitimize the
credentials of exercise scientists, the field is still full of misinformation. This misinformation
is due, in part, to the lack of standardization among agencies that certify instructors in
exercise and sports science. Many exercise certifications require minimal academic training.
In fact, the only requirements of some certification agencies are to attend a weekend-long
workshop and pass a written multiple choice exam. The result of such certifications is under-
qualified exercise professionals equipped with minimal theoretical knowledge of training
physiology and little or no ability to access the latest scientific research pertinent to their
profession. These certified exercise professionals often base their practice on a flawed set of
theoretical knowledge, personal experience or anecdotal hearsay, and non-peer reviewed
publications. Inevitably, misinformation leaks into the field and exercise specialists are
poorly equipped to evaluate the legitimacy of information, resulting in a plethora of devices,
nutritional supplements, and program theories that have little or no scientific merit.
The intention of academia and practice should be to constantly evolve with the literature in a
quest to create highly effective exercise programs that are based on current knowledge. We
propose that evidence-based practice be taught in undergraduate exercise science programs
as the foundation of all exercise programming. The purpose of this paper is to introduce the
structural framework of EBP as it relates to exercise science and to present the advantages
and limitations of EBP in the discipline of exercise science.
1. The Mechanics of Evidence-Based Practice
Sackett et al. have suggested that EBP is applicable in three distinct facets of medicine:
prognosis, diagnosis, and intervention.[17] While it might be argued that there are diagnostic
and prognostic components of exercise science, EBP’s primary application in exercise is at
the intervention or programming level. Thus, we will focus solely on the programming
aspect.
1.1 Step One: Develop a question
The evaluation and interpretation of client or patient data should lead to the development of
a focused, practical question.[17–20] The question should include information about the
subject population, exercise parameters (e.g. duration, frequency, intensity, etc.), and desired
adaptations. Questions that are too broad will yield enormous amounts of information
making interpretation of the literature difficult. Narrowing the population will result in a
smaller and more focused list of abstracts. When considering the population, at least five
Amonette et al. Page 2
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
questions should be addressed: 1) is the scenario gender specific, 2) are there underlying
clinical issues, 3) what is the training experience of the client, 4) what is the chronological
age of the client and, 5) what is the desired outcome of the program (e.g. increased, strength,
power, cardiovascular fitness, etc.)? Each of these questions may be useful in narrowing the
search and providing better evidence to construct the program.
1.2 Step Two: Search for Evidence
Acquiring appropriate, reputable evidence has become increasingly easier with the
availability of peer reviewed research on the internet. The definition of “evidence” has been
a source of debate as some have mistakenly assumed that advocates of EBP believe that
research alone constitutes evidence. Others have argued strongly for the value of clinical
intuition and experience as important contributors to evidence.[21,22] We believe that there
are three primary sources of evidence: professional experience, academic preparation, and
research knowledge.
1.2.1 Sources of evidence—When evaluating the three sources of evidence, it is
important to understand that each element of knowledge is incomplete, open to
interpretation, and therefore potentially biased. Professional experience can be a valuable
source of evidence. Lessons learned through field experience can reinforce academic
knowledge. However, it is vital to understand that knowledge gained through professional
experience is the least objective and most influenced by bias. For instance, in prescribing
medicine, doctors may be influenced by relationships with drug companies, the preference
of their mentors, and the static set of knowledge taught in medical school. While this
information is often valid, it is important to understand that it may not represent the best
treatment scenario. Exercise science practitioners are prone to these same biases. It is
difficult to deviate from methodologies taught by mentors and well-respected colleagues.
While many of these methodologies are valid and effective, mentors were, at best, working
from the best evidence available at that point in time.
Second, academic preparation provides a valuable source of evidence. The best professors
strive to incorporate recent research findings into courses teaching foundational scientific
principles. Academic courses typically utilize textbooks containing fundamental physiology
knowledge that is needed to read scientific research. However, there are two inherent flaws
to academic preparation: 1) the material delivered in academic lectures is often outdated by
the time it is presented and 2) lecture material is subject to the personal bias and current
knowledge of the professor. By the time a professor prepares and delivers a lecture, new
evidence has already been added to the body of knowledge. It is estimated that by the time a
new edition of a textbook is published, it is at least one year out of date;[23] similarly, with
the time required to develop coursework, academic lectures are likely several months out of
date by the time they are delivered--assuming they are updated each semester with the latest
evidence. Like practitioners, instructors are prone to bias. There is a tendency for instructors
to teach with a style similar to those who mentored them. Additionally, there is a propensity
to teach the very material that one was taught. Thus, when information is presented to
students it may be severely out of date; this underscores the need for the incorporation of
less biased research evidence.
Scientific research constitutes the level of evidence that is least prone to bias. The motto for
the Royal Society of London is the Latin phrase, “nullius in verba," which is translated, "on
no man's word." The best way to minimize bias is to remove the human element and let the
data speak for itself. While the interpretation of research evidence can be biased, research
evidence per se is less biased than personal experience, textbooks, or academic lectures. It is
our opinion that research evidence should provide the foundation for all practical
Amonette et al. Page 3
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
programming decisions. Empirical data should exert the ultimate influence on exercise
programming as it is a less biased form of evidence.
1.2.2 Gathering Evidence—In past generations, the collection of peer reviewed
materials required travel to libraries, searching through card catalogs, retrieving materials
from library shelves, and extensive photocopying. Today, the internet enables easy access to
quality resources including medical databases and peer reviewed journal articles online.
Instead of traveling to the library, practitioners need only to search topics using publicly
available databases such as PubMed and Google Scholar. The result is a vast availability of
research requiring minimal effort.
1.3 Step Three: Evaluate Evidence
The proponents of EBP argue that there is a hierarchy to evidence and that not all evidence
(even scientific research) should be considered equal.[20] The highest level of evidence is a
systematic review of randomized controlled trials.[24] This type of research evidence is
assigned a Level 1a ranking as it represents a series of replicated randomized controlled
trials. Level 1b evidence is a single randomized controlled trial with narrow confidence
intervals.[24] Systematic reviews of non-experimental studies (e.g. cohort studies), both
single well-designed cohort studies and poorly designed randomized controlled trials, and
outcomes research are given rankings of 2a, 2b, and 2c, respectively.[24] Systematic
reviews of case-control studies (3a) and case-control studies (3b) are given lower rankings
due to the greater potential for bias.[24] Finally, expert opinion, textbooks, decisions based
on mechanistic research (basic science), and practical experience are given Level 5 rankings.
[24] In this system, the research which is least prone to bias, replicated randomized
controlled trials (i.e., a systematic review), is recognized as the highest level of evidence
while the information that is most prone to bias, expert opinion, is assigned the lowest level
of evidence. This provides an impartial method of ranking evidence and determining its
influence on practical decision making.
1.4 Step Four: Incorporate Evidence Into Practice
The highest available level of evidence should be used as the basis for exercise prescription.
If practice is currently founded on reputable Level 5 evidence, then it is likely that new
evidence will only fine tune current exercise programs. However, it is prudent for all
individuals who prescribe exercise to understand the science upon which prescriptions are
based. This may be especially important for exercise professionals who currently base their
practice on non-peer reviewed material, professional experience, non-expert opinion, or less
reputable certification agencies.
In medicine, EBP is incorporated at the individual level [25]; the patient has a voice in
treatment options. EBP in exercise science should also include the input of the individual.
Exercise scientists will increase their professional credibility by discussing the evidence
behind program development with their clients/patients. This is particularly important when
research leads to a non-traditional training approach or goes against current trends.
In the past, patients of medical doctors blindly followed their recommendations based on the
authority of their office. Some in the medical community adamantly oppose the shift to
medical practice based on the authority of research evidence, disregarding the fact that the
science upon which recommendations are made is the ultimate authority, not a physician.
The shift from authoritarian medicine (“Do this because I said so”) to authoritative medicine
(“Do this because research evidence says so”) produces less biased medical prescription[26]
and will yield similar results in exercise prescription.
Amonette et al. Page 4
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
1.5 Step Five: Routinely Re-evaluate the Evidence
The final step in EBP is a constant re-evaluation of practice. It is sensible for practitioners to
continually read on particular subjects in order to stay abreast of new studies relevant to
their field. However, it is impossible to keep up with every journal and thus it is necessary to
routinely repeat searches on a particular topic.
2. Potential Criticisms and Benefits of EBP in Exercise Science
2.1 Potential Criticisms of EBP in Exercise Science
A variety of arguments have been levied against evidence-based practice in the field of
medicine. While we believe that EBP is both important and necessary to the advancement of
exercise science, we recognize that similar contentions will be raised to its inclusion in our
field.
Some have suggested that the implementation of EBP minimizes the importance of the
practitioner’s experience and intuition; this argument is certainly applicable to the
prescription of exercise. We acknowledge that personal experience is a valuable source of
evidence and, in many cases, the only source of evidence to substantiate practice. However,
the prudent search for additional information can only improve practice and add to the
repertoire of experienced exercise professionals. In many cases, research validates what the
practitioner has known for years through practical experience or intuition. However, at times
research goes against popular thought.
A second argument against EBP is that it removes the “art” or creativity from practice. This
is certainly a valid concern as creativity in program design can mitigate the monotony of
exercise training. Some contend that focusing on evidence as the driving factor for practice
could lead to a “cook book” approach where every individual gets the same treatment.[27]
While this is a valid concern, the current state of the exercise industry suggests a need for
the re-evaluation of programs based on evidence.
Popular trends in exercise training including the use of new devices, dietary supplements,
and novel programming techniques are often implemented based on the recommendation of
expert or non-expert opinion alone (Level 5 evidence). Faced with a dearth of evidence to
substantiate such practice, exercise specialists argue that the use of these techniques
constitutes the “art” or creativity of training. However, exercise specialists must not violate
the proven principles of training physiology for the sake of “art”. Music is a beautiful art;
talented composers are able to carefully arrange notes to create beautiful expressions.
Thousands of songs have been written from only twelve musical notes. Each song involves a
unique arrangement of melodies, harmonies, rhythms, etc. It is the arrangement of these
twelve notes that results in the creativity of each composition. Despite the limited number of
notes, each song has a unique “sound.” The same can be said of the art of exercise training.
While the proven concepts of training physiology may limit the strategies employed, it
certainly does not limit creativity. Instead, exercise specialists’ ability to creatively order
volume, intensity, rest periods, tempo, and exercises, using established evidence, typifies the
art of training.
2.2 Benefits of EBP in Exercise Science
We believe that there are two primary benefits of the inclusion of EBP into exercise
prescription. First, EBP will improve the quality of exercise programming. The consuming
desire of an exercise professional who wants to excel should be to provide the best exercise
program for every individual based on the current set of knowledge. The result of the
continuous search for evidence is a better product for the client/patient.
Amonette et al. Page 5
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Second, the incorporation of EBP will enhance the legitimacy of our profession. Although
there are many qualified and outstanding graduates of exercise science programs employed
as exercise specialists, the lack of licensure hurts our credibility with medical professionals
and with the general public. The credibility crisis is worsened by a multitude of
certifications requiring varying levels of competencies. Between certification agencies, there
exist varying recommendations as to the appropriate exercise prescriptions and differing
terminology to describe them. This creates problems when exercise specialists converse with
each other and with medical professionals. Therefore, the incorporation of evidence will
provide a common foundation upon which various groups can agree. Additionally, EBP
gives authority to the exercise professional. Instead of standing behind agency
recommendations, or answering questions based on academic knowledge, we can stand on
the credibility of the latest research findings.
3. Incorporation of EBP Into Exercise Science
There are two viable points of entry for EBP into the discipline of exercise science:
undergraduate programs and national certification agencies. These two avenues will capture
the majority of the new professionals who will fill leadership roles within the exercise
community.
There are several clear ways to incorporate EBP into undergraduate exercise science
programs. One, teach a mandatory class on EBP. This course would introduce the concepts
of EBP and provide practical instruction in: constructing answerable questions, searching for
evidence (research), and evaluating research to reach practical conclusions. Most
importantly, this course would emphasize the dynamic nature of scientific knowledge; i.e.,
that students should stay abreast of and search for current best evidence (especially those not
in research positions) and not base their training and coaching entirely on information
gained during an undergraduate education. Two, a more thorough approach, would
incorporate EBP as an undertone of the entire program. Thus, in addition to standard
lectures on basic physiologic and physical principles, each class would involve searches for
best evidence to answer specific questions. By graduation, students would have years of
practice finding and evaluating research. This repetitive exposure is particularly important
for those who will not have careers generating research but who can and should be
competent research consumers. Three, students could complete a senior EBP thesis,
investigating a specific question. A project of this nature would necessitate the
implementation of one or both of the previously discussed options so that students would
have adequate familiarity with the concepts of EBP.
The other readily accessible route by which EBP could be introduced to the exercise science
community is through the certification process. The two most highly regarded certifying
bodies in the exercise science field are the American College of Sports Medicine (ACSM)
and the National Strength and Conditioning Association (NSCA); not incidentally, both of
these agencies require a bachelor’s degree in an exercise-related or allied health field to even
test for their higher level certifications. However, both agencies also offer certifications for
personal trainers that require only a high school diploma or its equivalent. Recognizing that
commercial demand for personal trainers and coaches makes it practically impossible to
require a college degree for all certifications, the inclusion of EBP as a fundamental
component of these “lower level” certifications would serve to further elevate the profession
in competency, prestige, and ultimately, public perception. As organizations, the ACSM and
NSCA would benefit from both the increased prestige of their certifications and the
increased revenue from mandatory workshops necessary to teach the concepts of EBP.
Amonette et al. Page 6
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Although undergraduate programs and national certifications will expose a large portion of
incoming exercise professionals to the principles of EBP, admittedly, sub-standard
organizations will continue to certify under-qualified trainers. However, strengthening the
professional skills of those that obtain undergraduate degrees or upper-tier certifications will
create a clear distinction between those that are truly competent to prescribe exercise and
those that are not.
4. Conclusion
A. Bradford Hill stated, “All scientific work is incomplete--whether it is observational or
experimental. All scientific work is liable to be upset or modified by advancing knowledge.
That does not confer upon us a freedom to ignore the knowledge we already have, or to
postpone the action that it appears to demand at a given time.” As exercise professionals, we
are obligated to act based on the current state of scientific knowledge to develop the best
possible programs for our clients/patients. In doing so, we must recognize that the best
program in 2010 may not be the best program in 2015. Evidence-based practice is not a new
concept; there are certainly exercise professionals who already employ its principles. In
keeping with the motto of the Royal Society of London (“nullius in verba”), we propose that
the use of evidence be the driving component of exercise prescription. To implement this
philosophy, the principles of EBP must be incorporated into the curriculum of exercise
science programs. Our appeal to exercise science instructors and practitioners is to teach and
implement programs founded on the most recent scientific evidence. This will improve the
programs provided to the individual and our credibility as a profession.
Acknowledgments
K. English was partially supported by a National Center for Medical and Rehabilitation Research (NICHD) at the
National Institute of Health (T32 HD007539).
REFERENCES
1. Huxley AF. Cross-bridge action: present views, prospects, and unknowns. Journal Of Biomechanics.
2000; 33(10):1189–1195. [PubMed: 10899327]
2. Huxley AF, Niedergerke R. Structural changes in muscle during contraction; interference
microscopy of living muscle fibres. Nature. 1954; 173(4412):971–973. [PubMed: 13165697]
3. Huxley H, Hanson J. Changes in the cross-striations of muscle during contraction and stretch and
their structural interpretation. Nature. 1954; 173(4412):973–976. [PubMed: 13165698]
4. Huxley AF, Niedergerke R. Measurement of muscle striations in stretch and contraction. The
Journal Of Physiology. 1954; 124(2):46–47. [PubMed: 13175187]
5. Guyatt GH, Sackett DL, Cook DJ. Users' guides to the medical literature. II. How to use an article
about therapy or prevention. A. Are the results of the study valid? Evidence-Based Medicine
Working Group. JAMA: The Journal Of The American Medical Association. 1993; 270(21):2598–
2601. [PubMed: 8230645]
6. Oxman AD, Sackett DL, Guyatt GH. Users' guides to the medical literature. I. How to get started.
The Evidence-Based Medicine Working Group. JAMA: The Journal Of The American Medical
Association. 1993; 270(17):2093–2095. [PubMed: 8411577]
7. Wegscheider K. Evidence-based medicine - dead-end or setting off for new shores. Herzschr
Elektrophys. 2000; 11 Suppl 2:II/1–II/7.
8. Ellis J, Mulligan I. Inpatient general medicine is evidence based. Lancet. 1995; 346(8972):407.
[PubMed: 7623571]
9. Shorten A, Wallace M. Evidence based practice. Australian Nursing Journal. 1996; 4(2):22–24.
10. Simpson B. Evidence-based nursing practice: the state of the art. The Canadian Nurse. 1996;
92(10):22–25. [PubMed: 9095757]
Amonette et al. Page 7
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
11. Partridge C. Evidence based medicine--implications for physiotherapy? Physiotherapy Research
International: The Journal For Researchers And Clinicians In Physical Therapy. 1996; 1(2):69–73.
[PubMed: 9238724]
12. Partridge C, Edwards S. The bases of practice--neurological physiotherapy. Physiotherapy
Research International: The Journal For Researchers And Clinicians In Physical Therapy. 1996;
1(3):205–208. [PubMed: 9238735]
13. Compton J, Robinson M. The move towards evidence-based medicine. The Medical Journal Of
Australia. 1995; 163(6):333. [PubMed: 7565245]
14. Poolman RW, Sierevelt IN, Farrokhyar F, Mazel JA, Blankevoort L, Bhandari M. Perceptions and
Competence in Evidence-Based Medicine: Are Surgeons Getting Better? Journal of Bone & Joint
Surgery, American Volume. 2007; 89(1):206–215.
15. Madhok R, Stothard J. Promoting evidence based orthopaedic surgery: An English experience.
Acta Orthopaedica Scandinavica. 2002; 73:26–29. [PubMed: 12545660]
16. Hanson BP, Bhandari M, Audige L, Helfet D. The need for education in evidence-based
orthopedics. Acta Orthopaedica Scandinavica. 2004; 75(3):328–332. [PubMed: 15260426]
17. Sackett, DL.; Straus, SE.; Richardson, SW.; Rosenberg, W.; Haynes, RB. Evidence-Based
Medicine: How to Practice and Teach EBM. 2nd edition. Edinburgh: Hancourt Publishers Limited;
2000.
18. Hunt DL, Haynes RB, Browman GP. Searching the medical literature for the best evidence to solve
clinical questions. Annals Of Oncology. 1998; 9(4):377–383. [PubMed: 9636827]
19. Sackett DL, Rosenberg WM. On the need for evidence-based medicine. Journal Of Public Health
Medicine. 1995; 17(3):330–334. [PubMed: 8527187]
20. Antes G, Galandi D, Bouillon B. What is evidence-based medicine? Langenbeck's Archives Of
Surgery. 1999; 384(5):409–416.
21. Parker M. Whither our art? Clinical wisdom and evidence-based medicine. Medicine, Health Care,
And Philosophy. 2002; 5(3):273–280.
22. Michel LA. The epistemology of evidence-based medicine. Surgical Endoscopy. 2007; 21(2):145–
151. [PubMed: 17200906]
23. Fletcher RH, Fletcher SW. Evidence-based approach to the medical literature. Journal Of General
Internal Medicine: Official Journal Of The Society For Research And Education In Primary Care
Internal Medicine. 1997; 12 Suppl 2:S5–S14.
24. Law, M.; MacDermid, J. Evidence-Based Rehabilitation: A Guide to Practice. 2nd Edition.
Thorofare, NJ: SLACK Inc; 2008.
25. Straus SE, Sackett DL. Applying evidence to the individual patient. Annals Of Oncology: Official
Journal Of The European Society For Medical Oncology / ESMO. 1999; 10(1):29–32. [PubMed:
10076718]
26. Davidoff F, Case K, Fried PW. Evidence-based medicine: why all the fuss? Annals Of Internal
Medicine. 1995; 122(9):727. [PubMed: 7702236]
27. Sauerland S, Lefering R, Neugebauer EA. The pros and cons of evidence-based surgery.
Langenbeck's Archives Of Surgery. 1999; 384(5):423–431.
28. Franco G, Grandi P. Evaluation of medical decisions effectiveness: a 4-year evidence-based study
in a health care setting. International Archives of Occupational & Environmental Health. 2008;
81(7):921–928. [PubMed: 18057951]
29. Delorme TL, West FE, Shriber WJ. Influence of progressive resistance exercises on knee function
following femoral fractures. The Journal Of Bone And Joint Surgery American Volume. 1950;
32(A:4):910–924. [PubMed: 14784503]
30. DeLorme, TL.; Watkins, AL. Progressive resistance exercise: technic and medical application.
New York; United States: Appleton-Centry-Crofts; 1951.
31. Delorme TL, Watkins AL. Technics of progressive resistance exercise. Archives Of Physical
Medicine And Rehabilitation. 1948; 29(5):263–273. [PubMed: 18860422]
32. Gallagher JR, DeLorme TL. The use of the technique of progressive-resistance exercise in
adolescence. The Journal Of Bone And Joint Surgery American Volume. 1949; 31A(4):847–858.
[PubMed: 18142926]
Amonette et al. Page 8
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
33. Rhea MR, Alderman BL. A Meta-Analysis of Periodized Versus Nonperiodized Strength and
Power Training Programs. Research Quarterly for Exercise & Sport. 2004; 75(4):413–422.
[PubMed: 15673040]
34. Baker D. A series of studies on the training of high-intensity muscle power in rugby league
football players. Journal of Strength & Conditioning Research. 2001; 15(2):198–209. [PubMed:
11710405]
35. Lohman T, Going S, Pamenter R, Hall M, Boyden T, Houtkooper L, et al. Effects of resistance
training on regional and total bone mineral density in premenopausal women: a randomized
prospective study. Journal Of Bone And Mineral Research. 1995; 10(7):1015–1024. [PubMed:
7484276]
36. Spirduso WW, Cronin DL. Exercise dose-response effects on quality of life and independent living
in older adults. Medicine & Science in Sports & Exercise. 2001; 33(6 Suppl):S598–s608.
[PubMed: 11427784]
Amonette et al. Page 9
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Figure 1.
The fundamental steps of evidence-based practice in the context of individual exercise
prescription.
Amonette et al. Page 10
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Figure 2.
Theoretical knowledge base of student enrolled in traditional course or certification that
teaches only general principles (A) vs. a course or certification teaching both general
principles and the philosophy of evidence-based practice.
Amonette et al. Page 11
Sports Med. Author manuscript; available in PMC 2011 June 1.
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Amonette et al. Page 12
Table 1
Classic levels of evidence for rehabilitation practice. Table reprinted in part with the permission of SLACK
Inc.[24]
LEVEL CLASSIC "LEVELS OF
EVIDENCE” FOR THERAPY/
PREVENTION
PLACEMENT OF ADDITIONAL TYPES
OF CLINICAL EVIDENCE
1a Systematic review (with homogeneity) of
randomized controlled trials (RCT) Clinical practice guidelines (CPG's) where recommendations are based on
systematic reviews that contain multiple RCTs and the development includes
supplemental data or expert opinion to make recommendations only where
evidence is lacking
1b Individual RCT (with narrow Confidence
Interval)
1c All or none
2a Systematic review (with homogeneity) of cohort
studies
Lower quality CPGs that are based on informal evidence review and expert
consensus, where few RCT's are identified2b Individual cohort study (including low quality
RCT; e.g., <80% follow-up)
2c “Outcomes” research
3a Systematic review (with homogeneity) of case-
control studies Structured consensus processes based on quantitative ratings of agreement and
formal consensus processes using qualified experts
3b Individual case-control study
4 Case-series (and poor quality cohort and case-
control studies) Unstructured quantitative or qualitative expert consensus; large descriptive
practice analysis/survey that defines common ground; critical appraisal/
comprehensive systematic review or synthesis of biologic studies, or first
principles
5Expert opinion without explicit critical
appraisal, or based on physiology, bench
research, or “first principles.”
CPG's that are not based on the use of evidence review or quantitative data;
clinical protocols or rehabilitation theory
Sports Med. Author manuscript; available in PMC 2011 June 1.
