WarmUp and Stretching Chapter Objectives Identify the benefits

Warm-Up and Stretching

Chapter Objectives • Identify the benefits and components of a preexercise warm-up. • Assess the suitability of performing stretching exercises for a warm-up. • Identify factors that affect flexibility. (continued)

Chapter Objectives (continued) • Describe flexibility exercises that take advantage of proprioceptive neuromuscular facilitation. • Explain the mechanisms that cause the muscular inhibition that improves the stretch. • Select and apply appropriate static and dynamic stretching methods.

Section Outline • Warm-Up – Stretching During Warm-Up – Components of a Warm-Up

Warm-Up • Warming up can have the following positive impacts on performance: – Faster muscle contraction and relaxation of both agonist and antagonist muscles – Improvements in the rate of force development and reaction time – Improvements in muscle strength and power – Lowered viscous resistance in muscles (continued)

Warm-Up • Warming up can have the following positive impacts on performance (continued): – Improved oxygen delivery due to the Bohr effect whereby higher temperatures facilitate oxygen release from hemoglobin and myoglobin – Increased blood flow to active muscles – Enhanced metabolic reactions

Warm-Up • Stretching During Warm-Up – Research suggests dynamic stretching is the preferred option for stretching during warm-up. – Consider the range of motion and stretch-shortening cycle requirements of the sport when designing a warm-up.

Warm-Up • Components of a Warm-Up – A general warm-up period may consist of 5 to 10 minutes of slow activity such as jogging or skipping. – A specific warm-up period incorporates movements similar to the movements of the athlete’s sport. It involves 8 to 12 minutes of dynamic stretching focusing on movements that work through the range of motion required for the sport.

Section Outline • Flexibility – Flexibility and Performance – Factors Affecting Flexibility • • • Joint Structure Age and Sex Connective Tissue Resistance Training With Limited Range of Motion Muscle Bulk Activity Level – Frequency, Duration, and Intensity of Stretching – When Should an Athlete Stretch? – Proprioceptors and Stretching

Flexibility • Flexibility is a measure of range of motion (ROM) and has static and dynamic components. • Static flexibility is the range of possible movement about a joint and its surrounding muscles during a passive movement. • Dynamic flexibility refers to the available ROM during active movements and therefore requires voluntary muscular actions.

Flexibility • Flexibility and Performance – Optimal levels of flexibility exist for each activity. – Injury risk may increase outside this range.

Flexibility • Factors Affecting Flexibility – Joint Structure • Structure determines the joint’s range of motion. – Age and Sex • Older people tend to be less flexible than younger people; females tend to be more flexible than males. – Connective Tissue • Elasticity and plasticity of connective tissues affect ROM. (continued)

Flexibility • Factors Affecting Flexibility (continued) – Resistance Training With Limited Range of Motion • Exercise through a full ROM and develop both agonist and antagonist muscles to prevent loss of ROM. – Muscle Bulk • Large muscles may impede joint movement. – Activity Level • An active person tends to be more flexible than an inactive one, but activity alone will not improve flexibility.

Flexibility • Frequency, Duration, and Intensity of Stretching – Acute effects of stretching on ROM are transient. – For longer-lasting effects, a stretching program is required.

Flexibility • When Should an Athlete Stretch? – Following practice and competition • Postpractice stretching facilitates ROM improvements because of increased muscle temperature. • Stretching should be performed within 5 to 10 minutes after practice. • Postpractice stretching may also decrease muscle soreness although the evidence on this is ambiguous.

Flexibility • When Should an Athlete Stretch? – As a separate session • If increased levels of flexibility are required, additional stretching sessions may be needed. • In this case, stretching should be preceded by a thorough warm-up to allow for the increase in muscle temperature necessary for effective stretching. • This type of session can be especially useful as a recovery session on the day after a competition.

Flexibility • Proprioceptors and Stretching – Stretch reflex • A stretch reflex occurs when muscle spindles are stimulated during a rapid stretching movement. • This should be avoided when stretching, as it will limit motion.

Flexibility • Proprioceptors and Stretching – Autogenic inhibition and reciprocal inhibition • Autogenic inhibition is accomplished via active contraction before a passive stretch of the same muscle. • Reciprocal inhibition is accomplished by contracting the muscle opposing the muscle that is being passively stretched. • Both result from stimulation of Golgi tendon organs, which cause reflexive muscle relaxation.

Section Outline • Types of Stretching – – Static Stretch Ballistic Stretch Dynamic Stretch Proprioceptive Neuromuscular Facilitation Stretch • • Hold-Relax Contract-Relax Hold-Relax With Agonist Contraction Common PNF Stretches With a Partner

Types of Stretching • Static Stretch – A static stretch is slow and constant, with the end position held for 30 seconds. • Ballistic Stretch – A ballistic stretch typically involves active muscular effort and uses a bouncing-type movement in which the end position is not held. • Dynamic Stretch – A dynamic stretch is a type of functionally based stretching exercise that uses sport-specific movements to prepare the body for activity.

Types of Stretching • Proprioceptive Neuromuscular Facilitation (PNF) Stretch – Hold-Relax • Passive prestretch (10 seconds), isometric hold (6 seconds), passive stretch (30 seconds)

Positions for PNF Hamstring Stretch • Figures 13. 1 and 13. 2 (next slide) – Starting position of PNF hamstring stretch – Partner and subject leg and hand positions for PNF hamstring stretch

Figures 13. 1 and 13. 2

Hold-Relax • Figures 13. 3, 13. 4, and 13. 5 (next slide) – Passive prestretch of hamstrings during hold-relax PNF hamstring stretch – Isometric action during hold-relax PNF hamstring stretch – Increased ROM during passive stretch of hold-relax PNF hamstring stretch

Figures 13. 3, 13. 4, and 13. 5

Types of Stretching • Proprioceptive Neuromuscular Facilitation Stretch – Contract-Relax • Passive prestretch (10 seconds), concentric muscle action through full ROM, passive stretch (30 seconds)

Contract-Relax • Figures 13. 6, 13. 7, and 13. 8 (next slide) – Passive prestretch of hamstrings during contractrelax PNF stretch – Concentric action of hip extensors during contractrelax PNF stretch – Increased ROM during passive stretch of contractrelax PNF stretch

Figures 13. 6, 13. 7, and 13. 8

Types of Stretching • Proprioceptive Neuromuscular Facilitation Stretch – Hold-Relax With Agonist Contraction • During third phase (passive stretch), concentric action of the agonist used to increase the stretch force

Hold-Relax With Agonist Contraction • Figures 13. 9, 13. 10, and 13. 11 (next slide) – Passive prestretch during hold-relax with agonist contraction PNF hamstring stretch – Isometric action of hamstrings during hold-relax with agonist contraction PNF hamstring stretch – Concentric contraction of quadriceps during holdrelax with agonist contraction PNF hamstring stretch, creating increased ROM during passive stretch

Figures 13. 9, 13. 10, and 13. 11

Key Point • The hold-relax with agonist contraction is the most effective PNF stretching technique due to facilitation via both reciprocal and autogenic inhibition.

Types of Stretching • Proprioceptive Neuromuscular Facilitation Stretch – Common PNF Stretches With a Partner • • • Calf and ankle Chest Groin Hamstrings and hip extensors Quadriceps and hip flexors Shoulder

Partner PNF Stretching • Figures 13. 12 -13. 16 (next two slides) – Partner PNF stretching for the: • • • Calves Chest Groin Quadriceps and hip flexors Shoulders

Figures 13. 12 and 13. 13

Figures 13. 14, 13. 15, and 13. 16

Types of Stretching • Guidelines for Static Stretching – Get into a position that facilitates relaxation. – Move to the point in the ROM where you experience a sensation of mild discomfort. If performing partnerassisted PNF stretching, communicate clearly with your partner. – Hold stretches for 30 seconds. – Repeat unilateral stretches on both sides.

Types of Stretching • Precautions for Static Stretching – Decrease stretch intensity if you experience pain, radiating symptoms, or loss of sensation. – Use caution when stretching a hypermobile joint. – Avoid combination movements that involve the spine (e. g. , extension and lateral flexion). – Stabilizing muscles should be active to protect other joints and prevent unwanted movements.

Types of Stretching • Guidelines for Dynamic Stretching – Carry out 5 to 10 repetitions for each movement, either in place or over a given distance. – Progressively increase the ROM on each repetition. – Increase the speed of motion on subsequent sets where appropriate. – Contract the muscles as you move through the ROM.

Types of Stretching • Precautions for Dynamic Stretching – Move progressively through the ROM. – Move deliberately but without bouncing (movement must be controlled at all times). – Do not forsake good technique for additional ROM.