1 / 24

Factors Affecting Performance

Factor Affecting Performance (Powers CH 19) Lab Assessment of Performance (Powers CH 20) Training for Performance (Powers CH 21). 1. Factors Affecting Performance. Diet CHO intake Hydration. Bioenergetics -Anaerobic * Phosphagen * Glycolysis -Aerobic * VO2 Max * CO

komala
Download Presentation

Factors Affecting Performance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Factor Affecting Performance (Powers CH 19)Lab Assessment of Performance (Powers CH 20)Training for Performance (Powers CH 21)

  2. 1 Factors Affecting Performance • Diet • CHO intake • Hydration Bioenergetics -Anaerobic * Phosphagen * Glycolysis -Aerobic * VO2 Max * CO * O2 Delivery * O2 Extraction * Mitochondria CNS Function -Arousal -Motivation Performance Strength / Skill -Practice / NM Adaptations -Natural Endowment * Somatotype * Muscle Fiber Type • Environment • Altitude • -Heat / Humidity Powers CH 19, Fig 19.1, p409

  3. Possible Sites of Fatigue Fatigue 1 Brain / “Psyche” Spinal Cord • Inability to maintain power output or force during repeated muscle contractions Peripheral Nerves Muscle Sarcolemma T-tubular System CA++ Release Actin-Myosin Interaction Cross-Bridge Tension + Heat Force / Power Output Powers CH 19, Fig 19.2, p410

  4. 1 Sites of Fatigue • Central Fatigue (CNS) • Reduced # of functioning motor units involved in activity (spatial summation?) • Decreased motor unit firing rate (temporal summation?)

  5. 1 Sites of Fatigue • Peripheral Fatigue • Neural Factors • NM junction • Sarcolemma and t-tubules • Repeated stimulation of sarcomere = reduction of size/freq of APs • Decreased calcium release from SR = decreased A-M cross-bridge activation • Mechanical Factors • Resulting decrease in x-bridge cycling • Energetics of Contraction • Fatigue = mismatch btwn ATP utilization and ATP production • Cellular mechanisms (mostly influenced by increased intracellular inorganic phosphate) slow down ATP utilization rate to preserve ATP concentration and cellular homeostasis

  6. 3 Factors Limiting All-Out Anaerobic Performance • Less than 10 sec. (ultra short term) • Fast twitch (Type IIx) distribution • Anaerobic metabolism (ATP-PC) • Arousal / Motivation (enhances ms recruitment) • 10 sec. to 3 min. (short term) • Gradual shift from anaerobic to aerobic metabolism • FT (Type IIx and IIa) distribution • Anaerobic metabolism (glycolysis) • Elevated lactate levels and H+ concentration

  7. 3 Factors Limiting All-Out Aerobic Performance • 3 – 20 min. (moderate length) • Challenges maximal aerobic “power” – athlete with highest VO2 Max at an advantage • Aerobic metabolism • O2 transport • Mitochondrial utilization • Anaerobic metabolism • Blood lactate

  8. 3 Factors Limiting All-Out Aerobic Performance • 21 – 60 min. (intermediate length) • Oxidative metabolism • Conserved by running “economy” • Higher lactate threshold = greater performance (~ 90% VO2 Max) • Heat, humidity, hydration may be limiting factors • 1 – 4 hours (long term) • HHH • Liver, muscle glycogen depletion

  9. 1 Laboratory Assessment • Validity • Reliability • Control • Standardization • Sport Specificity • Accurate / timely interpretation of results

  10. 3 Field Tests for Aerobic Capacity • Maximum Aerobic Power • VO2 Max Testing • Large muscle groups • As sport-specific as possible • Endurance • Lactate threshold determination • Ventilatory threshold for LT prediction (eliminates need for blood draw) • Exercise Economy • Running economy = maximal gain from minimal work / energy expenditure • Influences VO2 Max scores and Lactate Threshold

  11. 2 Field Tests for Anaerobic Power • Jumping power tests • 40-yard dash • Running tests (200 – 800m) • Cycling tests (Wingate 30 sec. Test) • Med ball and/or machine testing Sport specific: what do you want to find out from test??

  12. Tests for Muscular Strength 2 • Strength • Max force production for 1 repitition • Power • Max force production per unit of time • P = F x d / t or w / t • Isometric Tests • Free Weights • Isokinetics • Dynamometry (Cybex, HHD,…)

  13. 2 Training Principles • Overload • Stimulus beyond what tissue is accustomed • Intensity, duration, frequency of training • Specificity • Muscle fiber type(s) recruited • Principal energy system involved (aerobic v. anaerobic) • Velocity of contraction (Vmax) • Type of contraction (concentric, eccentric, isometric) • Reversibility • Influences: • Gender • Genetics • Initial fitness levels

  14. 2 Training for Aerobic Power • Intensity may have greater influence than duration on VO2 Max • Interval Training • Quality / quantity of rest • Lactate management • LSD • Tempo Runs • Continuous, high intensity • Fartlek training (race strategy??)

  15. 1 Injuries and Endurance Training • Stress Fx • Plantar Fascitis • Achilles Tendinitis • PFPS / Chrondomalacia 10% Rule – training intensity or duration not increased more than 10% per week

  16. 1 Injuries and Endurance Training • Periostitis / “Shin Splints” • ITB Friction Syndrome • Pes Anserine Bursitis

  17. 1 Training for Anaerobic Power • Interval and Plyometric Training • Metabolically Specific!!

  18. 2 Training for Strength • Hypertrophy • Hyperplasia?? • Conversion • Based on training stimulus (IIx to IIa -or- IIa to IIx) • CNS Adaptations • Increased muscle recruitment • Increased motor neuron firing rates • Increased motor unit synchronization w/in movement pattern • Blunted neural inhibition (decreased GTO “firing”)

  19. Training Modes Isometric Isotonic Isokinetic Periodization Systematic transfer of tr. hours between training parameters Hypertrophy / Endurance Strength Power Primary Effects of Weight Training: Power / Speed Strength Local Muscular Endurance Increased Muscle Tone Flexibility Fat Reduction / Body Comp. Aerobic Power Skeletal / Structural Agility / Coordination 3 Training for Strength

  20. Training Parameters: Volume Intensity Frequency Rest Periods Exercise Order Circuit Training Supersets Standard Sets Eccentric “negatives” Accelerative movements Plyometrics PRE, PPLC2,… 3 Training for Strength

  21. 1 Warm up and Flexibility • Increase in Body Core Temperature • Static Stretching • Dynamic Flexibility • Ballistic Stretching

  22. 1 DOMS • Delayed onset muscle soreness 1 = structural damage to muscle fiber 2 = membrane damage 3 = calcium leaks out of SR 4 = protease activation – results in breakdown of cellular proteins 5 = inflammatory response 6 = edema and pain Powers CH 21, Fig. 21.4, p453

  23. 1 Overtraining • S/Sx: • Decrease in performance • Excessive weight loss • Chronic fatigue • Psychological staleness • Elevated HR, blood lactate levels during exercise • Increase in # of infections Powers CH 21, Fig. 21.7, p458

  24. 1 “Runner’s High” • β-Endorphins / β-Enkephalins • Endogenous morphine-like substances that interact with opiate receptors in brain areas involved in sensory transmission of pain impulses • β-endorphin formed in ant. pituitary gland from β-lipotrophin generated during fromation of ACTH

More Related