Muscular Strength & Endurance Assessments: Worth the Risk?
There
is an abundance of literature illuminating the positive benefits of
resistance training. Public health guidelines and position statements
recommend participating in structured resistance training due to its
protective benefit against diseases and disabilities. Resistance
training programs have been shown to increase strength(3),
musculoskeletal health(4), maintenance of functional abilities(5),
prevent osteoporosis(6), sarcopenia(7), and falls, fractures, and
disabilities(4). With the benefits evident, there has been an
increasing demand for resistance training. However, prescription of
resistance training has demanded a need for parameters for exercise
prescription. Muscular strength and endurance testing have been
frequently used to assess these parameters. However, performing
muscular assessments may propose a greater harm than benefit to your
client.
Muscular Strength & Endurance Tests: Defined
Muscular
strength testing is most often assessed through a one repetition
maximum (1-RM) test. The 1RM measures maximum strength through the
maximum capability of a muscle or muscle group to generate tension(8).
Furthermore it is the heaviest load one can move over a specific range
of motion in correct form for one repetition. On the other hand,
muscular endurance assessments, involve submaximal loads with maximum
number of repetitions performed (repetitions until failure)(8).
Potential Risks
Implementing
maximal and submaximal strength tests may impose dangerous consequences
due to the stresses imposed upon on the muscles, tendons, bones, and
connective tissue. Performing maximal load lifts or repetitions to
failure with an inadequate joint positioning, suboptimal coordination,
or poor mechanics can result in muscle tissue injuries, tears, and
muscle soreness. A study examined the effects of 1RM in healthy
individuals and found that 2.4% sustained an injury, and 58% endured
muscle soreness(9). Although, the injury response may seem low, the
goal of the fitness professional is to enhance clients musculoskeletal
health without putting them at risk. The large response of muscular
soreness may arise as something necessary to stimulate strength and/or
hypertrophy. However, despite the common conception - it is widely
misinterpreted. It has been clearly documented by Flan et al. that
muscle damage is not necessary for strength and size(10). His study
included two groups, one beginning with a large intensity and continuing
throughout and another group utilizing a slow gradual acclimation to
exercise with no structural muscle damage. Despite one group
experiencing muscular damage, both groups’ exhibits similar net
increases in muscle size and strength(10). Therefore it is evident
muscle damage is not necessary to receive strength training adaptions.
Imposing muscular strength and endurance assessments require a large
intensity and have high margins for muscle soreness and damage.
Although
it is clear muscle damage to promote size and strength is not
necessary, it still can provide regeneration of muscle tissue. However,
excessive amounts of damage can lead to disruption and even destruction
of sarcomeres (functional unit of muscles)(11). Execution of strength
tests, when one is not acclimatized, can result in excessive damage
leading to the declination of myofibrils and further damage of the
muscle. Another flaw with introducing such a large stimulus upon
initial stages can be seen with recovery. A study by Sayers et al.
found that if an initial bout is extreme it could result in greater than
70% in strength loss and it could take 30 up to 89 days to recover due
to loss of sarcomeres or chronic inflammation(12).
Other
potentials flaws with the muscular strength and endurance testing
include a large consumption time, limited application to exercise
program design and limited application to sport performance. Performing
muscular assessments are a burden regarding time efficiency. Testing
requires pretesting a few days prior to actual testing to familiarize
with procedure, providing a sufficient warm-up, and finally conducting
the test at a different time and date. The purpose of conducting
muscular assessments is a protocol in determining parameters for
exercise program design. Also, it can be used as a measure of strength
and determining efficacy of your program. However, no matter if a
client is an athlete, elderly, or a child, the tests are rarely
applicable in determining parameters. Correct periodization and
sequencing of training begins with lighter intensities and furthering
progression based on physiological and biomechanical adaptations.
Alternatives Assessments
Assessments
including anthropometric measurements, body composition, and
documentation of progression and sequencing of training are alternatives
to avoid the risks imposed by muscular strength and endurance
assessments. These assessments still allow someone to quantify strength
and size gains in safer manner.
What About Athletes?
The
use of strength and endurance testing may be regarded more appropriate
for athletic populations. For example, the National Football League
utilizes the 225 pound bench press until failure as part of its combine
training camp. A study measuring the combine results and draft status
found that the 225-Press was poor predictor of determining an athlete’s
ability to play at the next level(13). There were no differences
between draft position with a larger number of lifts. The test provides
a measure of strength but many other variables are involved in
performance. Therefore, it can be taken that strength tests have their
limited application with even athletes, as they are not true predictors
of performance.
A goal of one within the health and fitness field
is to ultimately positively assist the client or patient in pursuit of
reaching their goals. Muscular strength and endurance tests have shown
to produce a risk that may not be worth the reward in implementing a
health or performance promoting exercise program. Conducting the
assessments limit efficiency in time, provide unnecessary parameters for
program design, may cause injury or soreness resulting in ultimately
hindering client retention. Therefore, alternatives should be
considered to document progress of muscular strength and endurance.
Article Summary
BENEFITS
Determine Maximal Muscular Strength*
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Determine Maximal Muscular Strength*
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Determine Muscular Endurance*
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*Alternate Testing can be Substituted
Direct
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Indirect |
Muscle Damage
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Hinder Client Retention
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Destruction of Sarcomeres
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Poor Application to Performance
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Tear, Fray Tendons/Ligaments
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Time Consumption
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Edema (inflammation)
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Delay Training
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Soreness |
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- Winett RA, Carpinelli RN. Potential Health-Related Benefits of Resistance Training* 1. Preventive medicine. 2001;33(5):503-513.
- Evans WJ. Exercise training guidelines for the elderly. Medicine & Science in Sports & Exercise. 1999;31(1):12.
- LAYNE JE, NELSON ME. The effects of progressive resistance training on bone density: a review. Medicine & Science in Sports & Exercise. 1999;31(1):25.
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- Inez M, Pereira R, Sergio P, Gomes C. Muscular strength and endurance tests: reliability and prediction of one repetition maximumñreview and new evidences. Revista Brasileira De Medicina. 2003;9(5):336-346.
- Shaw CE, McCully KK, Posner JD. Injuries during the one repetition maximum assessment in the elderly. Journal of Cardiopulmonary Rehabilitation and Prevention. 1995;15(4):283.
- Flann KL, LaStayo PC, McClain DA, Hazel M, Lindstedt SL. Muscle damage and muscle remodeling: no pain, no gain? Journal of Experimental Biology. 2011;214(4):674.
- Mackey AL, Bojsen-Moller J, Qvortrup K, et al. Evidence of skeletal muscle damage following electrically stimulated isometric muscle contractions in humans. Journal of Applied Physiology. 2008;105(5):1620.
- SAYERS SP, CLARKSON PM, LEE J. Activity and immobilization after eccentric exercise: I. Recovery of muscle function. Medicine & Science in Sports & Exercise. 2000;32(9):1587.
- McGee KJ, Burkett LN. The National Football League combine: a reliable predictor of draft status? Journal of Strength and Conditioning Research. 2003;17(1):6-11.
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