NASM essentials of sports performance training
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NASM essentials of sports performance training


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to decreased overall strength.
FLEXIBILITY AND PERFORMANCE ENHANCEMENT
The debate amongst many professionals centers on the use of static stretching prior to
performance. There are many who have determined that static stretching negatively influences
performance based on reports of impaired balance, reaction times, movement times (80), and
jump height (76). There exist, however, some contradictory studies which reveal that static
stretching may increase lower-limb stiffness resulting in higher countermovement jumps (82)
and potentially having no impact on vertical jump heights (83). Of potential importance is the
varied approach to the subject of pre-activity static stretching. Hunter and Marshall (90) looked
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at the performance effects of chronic static stretching (static stretching integrated into a 10-week
program) versus the acute effects of static stretching (done immediately prior to performance
assessment). The acute effects may not equate to decreases in muscle stiffness and therefore the
results may not match those of Young and Elliot (80). Thus, the differences in the stretching
protocols seem to play a factor in the results seen between each study.
148 CHAPTER 4
The NASM Position on the Use of Flexibility
Training and Performance Enhancement
Overall, research shows that performance is influenced by static stretching and may decrease
jump height, balance, reaction times, and movement times. The acute effects of static stretching
on performance have led NASM to determine pre-activity flexibility should be limited to active-
isolated and dynamic stretches unless muscle imbalances are present that may impede proper
movement and limit performance. If static stretching is used to address these imbalances, it
should be followed with active-isolated and/or dynamic stretching to increase proper reciprocal
inhibition, neuromuscular efficiency, and motor neuron excitability pre-activity.
Furthermore, while some evidence suggests that an acute bout of static stretching may
inhibit muscular strength when performed in isolation (see the section on Flexibility and
Strength), we are not ready to infer that specific static stretching performed to correct muscle im-
balances and used in conjunction with active and dynamic stretching will equate to decreased
performance. On the contrary, research currently underway at the University of North Carolina is
beginning to show that a systematic approach that includes inhibition (foam roll), lengthening
(static stretching), activation (active stretching), and integration (dynamic stretching) may im-
prove human movement imbalances, decrease injury risk, and improve performance.
TIME OUT
Stretching Tips for Strength and Performance Enhancement
1. As a warm-up, static stretching prior to a strength training routine or competition should only
be used on areas that are determined as tight/overactive from the assessment process.
2. Static stretching (if incorporated before a strength workout or as a warm-up prior to competi-
tion) should be followed by active-isolated and/or dynamic stretching to improve neuromuscu-
lar efficiency.
3. Static stretching should be used post-workout or event to return muscles to normal resting
lengths and should be performed on the major muscles utilized during the workout or event.
4. Static stretching is contraindicated prior to activities requiring maximal effort unless muscle im-
balances are present.
5. Active-isolated and/or dynamic stretching can be used:
i. As a warm up by themselves if no muscle imbalances are present.
ii. As a warm up after static stretching if muscle imbalances are present.
iii. Prior to activities requiring maximal effort.
There are many stretching exercises designed to improve flexibility. Regardless of the method
chosen, individuals can achieve flexibility by manipulating the duration of the stretch, in-
tensity of the stretch, velocity of the movement, and frequency of the movements performed.
To achieve optimum soft-tissue extensibility with neuromuscular control, the individual
should follow the integrated flexibility continuum (corrective, active, functional). The risk of
injury is reduced when these stretching techniques are combined with an integrated training
program that focuses on neuromuscular efficiency at all levels. Further research is needed to
determine which flexibility technique is optimum for a given individual. 
SUMMARY
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REFERENCES
1. Alter MJ. Science of Flexibility, 2nd ed. Champaign, IL: Human Kinetics; 1996.
2. Chaitow L. Muscle Energy Techniques. New York: Churchill Livingstone; 1991.
3. Bandy WD, Irion JM, Briggler M. The effect of time and frequency of static stretching on flexibility of the
hamstring muscles. Phys Ther Oct 1997;77(10):1090\u201396.
4. Clanton TO, Coupe KJ. Hamstring strains in athletes: diagnosis and treatment. J Am Acad Orthop Surg
Jul\u2013Aug 1998;6(4):237\u201348. 
5. Condon SA. Soleus muscle electromyographic activity and ankle dorsiflexion range of motion during
four stretching procedures. Phys Ther 1987;67:24\u201330. 
6. Janda V. Muscle spasm\u2014a proposed procedure for differential diagnosis. Man Med 1991;199:6136\u2013139. 
7. Liebenson C. Rehabilitation of the Spine\u2014A Practitioners Manual. Baltimore: Williams & Wilkins; 1995.
8. Poterfield J, DeRosa C. Mechanical Low Back Pain: Perspectives in Functional Anatomy. Philadelphia:
WB Saunders; 1991.
9. Gossman MR, Sahrman SA, Rose SJ. Review of length-associated changes in muscle: experimental evi-
dence and clinical implications. Phys Ther 1982;62:1799\u2013808.
10. Halbertsma JPK, Van Bulhuis AI, Goeken LNH. Sports stretching: effect on passive muscle stiffness of
short hamstrings. Arch Phys Med Rehabil 1996;77(7):688\u201392.
11. Holcomb WR.. Improved stretching with proprioceptive neuromuscular facilitation. J NSCA 2000;22(1):
59\u201361.
12. Moore MA, Kukulka CG. Depression of Hoffmann reflexes following voluntary contraction and implica-
tions for proprioceptive neuromuscular facilitation therapy. Phys Ther Apr 1991;71(4):321\u201329.
13. Moore MA. Electromyographic investigation of muscle stretching techniques. Med Sci Sports Exerc 1980;
12:322\u201329.
14. Sady SP, Wortman M, Blanke D. Flexibility training: ballistic, static, or proprioceptive neuromuscular fa-
cilitation? Arch Phys Med Rehabil Jun 1982;63(6):261\u201363.
15. Sherrington C. The Integrative Action of the Nervous System. New Haven: Yale University Press; 1947.
16. Wang RY. Effect of proprioceptive neuromuscular facilitation on the gait of patients with hemiplegia of
long and short duration. Phys Ther Dec 1994;74(12):1108\u2013115.
17. Sapega A, Quedenfeld T, Moyer R. Biophysical factors in range of motion exercises. Phys Sports Med
1981;9:57.
18. Tardieu C. Adaptation of connective tissue length to immobilization in the lengthened and shortened
position in the cat soleus muscle. J Physiol 1982;78:214.
19. Woo SLY, Buckwalter JA. Injury and Repair of the Musculoskeletal Soft Tissues. Rosemont, IL: American
Academy of Orthopedic Surgeons; 1987. 
20. Johns RJ, Wright V. The relative importance of various tissues in joint stiffness. J App Physiol 1962;
17(5):824\u201328.
21. Selye H. The Stress of Life. New York: McGraw-Hill; 1984. 
22. Butler D, Magee DJ, Quillen WS. Nerve: Structure, Function, and Physiology. In Zachazewski JE, et al.
Athletic Injuries and Rehabilitation. Philadelphia: WB Saunders; 1996. p 170\u201383.
23. Butler D. Mobilization of the Nervous System. Melbourne: Churchill Livingstone; 1991.
24. Hiromada J. On the nerve supply of connective tissue of some peripheral nervous system components.
Acta Anat 1963;55:343. 
25. Sunderland S. Nerves and Nerve Injuries, 2nd ed. Edinburgh: Churchill Livingstone; 1978.
26. Elvey RL. Brachial Plexus Tension Tests and the Pathoanatomical