Transcript Warm-Up
Chapter 10 Warm-Up and Flexibility Copyright © 2012 American College of Sports Medicine • Preparation can be viewed as chronic or acute. • Chronic: training program, diet and recovery over time • Acute: strategic plan before a workout or competition—dietary intake and fluid, mental focus, competition strategy and warmup Copyright © 2012 American College of Sports Medicine Warm-Up • Overview – Performing low-intensity exercise to prepare the body for more intense physical activity – Increases in intensity progressively – Passive vs. active – General vs. specific – Increases muscle temperature – Should last 5-15 minutes [P-sauna, shower, heat: A-exercise] [g precedes s] Copyright © 2012 American College of Sports Medicine Examples of General & Specific Warm-Ups Copyright © 2012 American College of Sports Medicine • At the very least a proper warm-up can enhance performance and may reduce injury potential. (p.166) • The responses on the following slide are thought to elicit greater strength, power, ROM, speed, agility, and endurance following a warm-up. Copyright © 2012 American College of Sports Medicine Warm-Up (cont’d) • Physiology of Warming Up Muscle & core temp Blood flow Nerve conduction velocity & neural activation O2 consumption Speed of metabolic reactions Joint/CT & skeletal muscle viscosity & resistance Release of O2 from hemoglobin & myoglobin (Bohr effect) Muscle glycogen breakdown & glycolysis Heart rate & cardiac output Mental preparedness & psychological functioning Copyright © 2012 American College of Sports Medicine Warm-Up (cont’d) • Performance Effects – After 3-5 min of warm-up, enhanced performance in: • Vertical jump • Swimming time • Running time • Cycling power – Key elements of warm-up 1. Increase muscle temperature 2. Increase VO2 3. Minimize fatigue • The longer the duration of the event, the less likely a warm-up will affect performance. Copyright © 2012 American College of Sports Medicine Warm-Up (cont’d) • Warm-Up Versus Postactivation Potentiation – Potentiation protocol • Activated motor units stay facilitated for a period of time following maximal or near-maximal muscle contractions • Muscle strength, power, & endurance can be enhanced • Viewed by some as a warm-up • Viewed by others as a separate entity & part of workout • The potentiating effects of heavy lifting to maximally recruit fast-twitch fibers prior to maximal anaerobic exercise Copyright © 2012 American College of Sports Medicine The Warm-Up Continuum Copyright © 2012 American College of Sports Medicine Warm-Up (cont’d) • Dynamic Versus Static Warm-Ups – Dynamic warm-up: enhances performance – Static warm-up • Shown to reduce performance when performed before activity by itself • Light stretching coupled with dynamic warm-up may be effective to optimize performance • Intense stretching recommended for strength/power athletes after workout, in cooldown • It is thought that high-intensity stretching reduces musculotendinous stiffness thereby lessening the ergogenic effects of the stretch shortening cycle. Musculotendinous stiffness is related to maximal concentric and isometric force production and decreases following static stretching. Copyright © 2012 American College of Sports Medicine Flexibility • Overview – A measure of joint ROM without injury – An important health-related component of fitness – Types [active-unassisted; passive-assisted, where the final position is held] • Static flexibility • Dynamic flexibility • Ballistic flexibility Copyright © 2012 American College of Sports Medicine Flexibility (cont’d) • Health Benefits – Maintains appropriate muscle lengths – Improves muscle balance – Improves muscular weakness – Reduces risk of injury – Improves posture – Improves ability to move – Relieves stress – Reduces risk of low-back pain Copyright © 2012 American College of Sports Medicine Flexibility (cont’d) • Improvements in Athletic Skills – Olympic weightlifter: proper overhead position in the snatch – Gymnast: proper position during a split – Ice hockey goalie: blocking the puck at many difficult angles – Tennis player: maximizing velocity & accuracy of serve – Volleyball player: blocking a shot & spiking the ball – Hurdler: elevating over the hurdle w/o deviation in stride Copyright © 2012 American College of Sports Medicine Flexibility (cont’d) • Flexibility and Injury Prevention – May decrease risk of pain & injury – Increases compliance of tendon – Reduces acute tendon stiffness – Decreases hysteresis – Enhances joint ROM [amount of energy lost as heat during the elastic recoil) Copyright © 2012 American College of Sports Medicine Flexibility (cont’d) • Factors Affecting Flexibility – Joint structure – Muscular imbalance – Muscular control – Age – Gender – CT (tendons, ligaments, fascia, joint capsules, & skin) – Bulk – Training in a limited ROM – Activity level Copyright © 2012 American College of Sports Medicine Flexibility (cont’d) • Types of Stretching • An active stretch is when the athlete provides the force, a passive stretch is when a partner or device provides the force. – Static – Dynamic – Ballistic – Proprioceptive neuromuscular facilitation (PNF) • Hold-relax • Contract-relax • Hold-relax with agonist contraction • Contract-relax with agonist contraction Copyright © 2012 American College of Sports Medicine Flexibility (cont’d) • Flexibility Training Guidelines – Stretch after workout or after general warm-up – Select stretches that work each major muscle group – Stretch for at least 10 minutes – Perform at least 4 reps/muscle group at least 2-3 days per week – Select dynamic, static, or PNF stretches – Consider ballistic stretching for athletes in explosive sports – Take static stretches to point of mild discomfort & hold 15-60 sec – Allow a 6-sec contraction followed by a 10-30 sec assisted stretch for PNF stretches Copyright © 2012 American College of Sports Medicine The Cooldown • Is a postworkout light exercise activity • Example: 5-10 min of walking/cycling • Provides an adjustment period between exercise & rest • Helps return body to homeostasis in a controlled manner • Facilitates waste removal • Reduces cardiovascular responses appropriately • Institutes a greater sense of well-being • Provides time for stretching to increase flexibility Copyright © 2012 American College of Sports Medicine