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PHYL2730 EXAM NOTES

Mikaela Sullivan PHYL2730 End of Sem Exam English 96 cards

Cards in this deck (96)

  1. 1Contribution of Energy Systems30s - 80% anaerobic, 20% aerobic
    60-90s- 45% anaerobic, 55% aerobic
    120-190s - 30% anaerobic, 70% aerobic
  2. 2PCr & ATP Between Fibre Types- no diff in resting ATP concentrations
    - 3x more PCr than ATP stores at rest
    -5-15% more PCr stored in TIIB fibres than TI
    -aerobic contributions in sprint vary 10-30% in people
  3. 3Possible Causes of FatigueSubstrate depletion: ATP, PCR, glycogen, glucose
    Metabolic by-products: Mg2+, H+, ADP, NH3, Pi, La-, free radicals, heat
    -Lactic Acid Production: within exercising muscle high during intense sprint
  4. 4How does Lactic Acid cause Fatigue-LA produced in muscle, dissociates to lactate ion and H+
    -H+ accumulates in cell causing acidosis (decreases pH)
  5. 5Buffering Proteins-Cell has proteins that 'buffer' against accumulating H+
    -Recuce rate pH falls, slowing rate of fatigue
    -H+ accumulation interferes w/ glycolytic pathway
    -Acidosis impair activity of glycolytic enzyme PFK - less energy available for resynthesis
  6. 6Enzyme Systems causing Fatigue-ATPases that act as pumps in muscle
    - Ca2+ ATPase
    -NA+-K+-ATPase
  7. 7Sarcoplasmic Reticulum and Calcium Homeostasis-Low CA2+ATPase activity->reduced CA re-uptake
    -Reduced CA re-uptake cause incomplete relaxation between contractions
    -Pi released from PCr breakdown in sprint, binds to CA in sarcoplasmic reticulum and reduce net CA release
  8. 8Na-K ATPase role in Fatigue-In repetitive tasks K lost from muscle cell and intracellular Na increases
    -NA-K ATPase fail to operate at high enough rate to restore ionic gradient
  9. 9What makes a good sprinter?-Higher P output due to genetics & training
    -More TII fibres
    -Greater hypertrophy of existing muscles
    -Better synchronisation of motor-units
    -High PFK activity (no change resting ATP or CrP with training)
  10. 10How does change in buffering capacity affect athlete?-Higher intramuscular buffering capacity (through protein) than an endurance athlete
    -Ability to neutralise protons delays onset of fatigue -> sprinter better at translocating protons out of active muscle cell
  11. 11Sprint training causes an increase in...-CS & PFK activities
    -VO2 Max
    -30s sprint performance
    -Sprinters have higher post-exercise blood L conc/n ->due to training-induced adaptations to the glycolytic pathway
    -NO CHANGE fibre compotition
  12. 12What is High Intensity Interval Training (HIIT)?Repeated sessions of brief, intermittent exercise, performed with an "all out" effort or at an intensity close to that which elicest peak oxygen uptake (>90% VO2 Peak)
  13. 13Effects of HIIT?-HIT sever wks improves aerobic evergy metabolism (maximal aerobic capacity & max. activities of mitochondrial enzymes)
    -6xHIT in 2 wks increase oxidative capacity in skeletal muscle and improve performance during tasks that rely on aerobic energy metabolism
  14. 14Why is HIIT important?-Resynthesis of PCr in muscle is aerobic process; improvements in aerobic fitness will allow faster PCr recovery
    -Removal LA (restoration of normal pH) is aerobic process
    -So, multiple sprint training improves anaerobic and aerobic capacity
  15. 15Fibre Type distribution between different liftersBody Builders: highest T1 % and area
    Powerlifters: higher TII % and area
    Weightlifters: TII % and area greatest
  16. 16Can fibre types change with training?-Cannot change between TI and TII
    -Movement from TIIa<->TIIb is possible with training, TIIb-TIIa more common
  17. 17What is stretch-induced hypertrophy?-Immobilisation of skeletal muscle in shortened and lengthened positions resulting in rapid loss & addition of sarcomeres
    -16 workouts necessary to produce significant hypertrophic changes
  18. 18What are the early adaptations to resistance training?-Neural: skill, reduced inhibition, improved synchronisation
    -Strength paralleled by changes in EMG
    -Later changes in strength are not matched by changes in EMG (& are therefore myogenic changes)
  19. 19How does strength training affect neural adaptations?-Involves recruitment of high threshold motor units not previously recruitable and an increased firing rate of motor units
  20. 20How does strength training affect agonist muscles?-Agonist muscles make greater contribution to movement & there is reduced co-contraction of antagonists
    -Co-contraction of antagonists provide joint stability and improve movement coordination
    -Antagonist movement most common in high velocity movements where precision & braking's required
  21. 21What does the combination of sprint and endurance training cause?-Adding strength to endurance: endurance does not improve
    -Endurance added to strength: studies have shown strength gains are impaired
  22. 22What are the reasons why concurrent strength and endurance training is not successful?-Fatigue reduce quality of training & impair rate of adaptation
    -Fibre types->endurance training leads to adaptations to TI and increase in mitochondrial density. Mitochondria may occupy to space which would otherwise be taken up by contractile proteins (body builders vs. powerlifters)
  23. 23Why does upper body strength decrease with endurance running?-Release of catabolic hormones in response to fall in blood glucose during endurance work; non-active muscle proteins may be catabolised for gluconeogenesis
  24. 24Unaccustomed eccentric exercise results in:-Loss of strength
    -Reduction in ROM
    -Muscle soreness
    -Elevated plasma CK activity
    -Limb swelling
  25. 25What is Delayed Onset Muscle Soreness (DOMS)?-Muscle soreness late in exercise bout & immediate recovery period
    -12-48hrs after exercise
    -Occurs w/ eccentric muscle action
    -Causes: structural damage to muscle cells & inflammatory reactions within muscles
    -Maximises resistance training response
  26. 26What is the 'Repeat-Bout' Effect?-1st bout of eccentric exercise = damage
    -2nd bout (within several weeks) = less damage
    -Protection may last 6-12 months
  27. 27Isotonic Resistance Training-Isotonic contractions involve muscle contraction against a moveable load
    -Muscle does NOT exert constant tension throughout ROM
    -Tension varies with mechanical advantage
  28. 28Isometric Resistance Training-Isometric contractions involve contraction a muscle at a fixed angle against an immoveable object e.g. wall
    -Questionable specificity to most sports
  29. 29Isokinetic Resistance Training-Isokinetic contractions invole muscles contracting throughout the movement at a constant speed
    -Used in rehabilitation
    -Expensive and speed specific
    -NOT sport specific
  30. 30What is the purpose of periodisation of strength?-Change in training volume & intensity over the course of the year/season
    -Rest or reduced training periods/provides variety
    -Allow for peak at right time, e.g. athlete periodising over 4yrs for Olympics
  31. 31Performance differences for female athlete-Body composition: higher fat mass
    -Physiological responses: higher % muscle mass in lower body 60%, same CSA
    -Fibre Type distribution: fibre CSA less but distribution similar
  32. 32Cardiorespiratory differences in females vs. males-VO2 Max 20% lower
    -SV decrease, blood volume decrease due to lower haemoglobin levels
    -Substantial overlap in untrained males and females
  33. 33What is the female phenomenon 'energy deficit'?-Energy availability is primary cause of menstrual irregularities
    -Energy availability falls below 30%, menstruation will cease (30kcal/kg/FFM/day)
    -Amenorrheic athlete reduces her training and increase caloric intake by 10-20%, normal menses returns
  34. 34How do menstrual disturbances occur?-Long-term energy restriction leads to endocrine disturbances -> disruption to the hypothalamic pituitary axis -> oestrogen release is reduced
    -Low oestrogen levels reduce bone formation; bone becomes more sensitive to parathyroid hormone which promotes loss of calcium.
  35. 35What is Anorexia Athletica?-Exhibit signs of anorexia or bulimia
    -Excessive fear of becoming obese
    -Restriction of caloric intake
    -Weight loss (>5%)
    -Associated with menstrual dysfunction
    -May use binge eating & purging
  36. 36How does anaerobic capacity differ in a young athlete?-Capacity reduced
    -Decreased glycolytic capacity so produce less LA, less PFK
    -Recover quicker
  37. 37How Does Thermoregulation Differ in the Young Athlete-Decreased sweat rate: reliance on convection and radiation
    -Increased SA/m: more gain in hot and loss in cold environments
    -Slower rate of heat acclimitisation: increased risk of heat-related illness
  38. 38What Training Adaptations occur in the Young Athlete?-Body composition
    -Training can alter deposition of muscle, fat and bone
    -Training has biggest difference in relative fat mass at 14 yrs
  39. 39What are the expected benefits of resistance training in prepubescents?-13-3-% improvement in strength
    -Similar in boys and girls
    -2x/wk is sufficient
    -Factors responsible: Improved motor skill coodination, improved motor unit activation
  40. 40ACSM suggestions for resistance programs for young athletes-1-3 sets of 8-10 exercises: 6-15 reps
    -1-2 mins between sets, 2-3x/wk
    -begin 1 set of several upper and lower body exercises
    -emphasis on proper technique & safety
    -program variation: rubber tubing, weight machines, calisthenics
  41. 41What are the basic principles for aerobic training in young athletes?-Large muscular activity resulting in accumulation of 30-60min/day
    -Allow to be naturally active
    -Allow to control intensity and duration
    -Included in activities that develop basic motor and sport skill
    -Weight-bearing for bone aquisition
  42. 42What physiological characteristics come with ageing?-Increased adiposity (fat mass)
    -Reduced muscle mass (sarcopenia)
    -Reduced strength (i.e. grip strength)
    -Reduced aerobic capacity
    -Reduced BMD
  43. 43How does diet effect the muscle?-Low protein diets lead to loss in muscle mass & function
    -Protein intakes of at least 1g/kgBW/day more appropriate
    -Digestive system impaired with age
  44. 44How does age affect hormones and muscle mass?-Decrease growth hormone (GH)
    -Decrease testosterone & oestrogen
    -Oestrogen: levels decline drastically at menopause or amenorrhea
    -Causes decrease in muscle mass
  45. 45What are the consequences of sarcopenia?-Basal Metabolic Rate (BMR) decreases 15% between 30-80
    -Decrease BMD
    -Decrease Aerobic capacity
    -Decrease functional capacity: walking, stair climbing
  46. 46How does cardio respiratory fitness change with age?-Cardiorespiratory endurance declines with age
    - ~1% each year
    -Training before peak (25yrs) is beneficial, creates greater buffer
  47. 47How & why should resistance training be implemented for older adults?-Older adults respond quickly to resistance training; 3x/wk w/ 1x high velocity
    -Resistance training shown to increase plasma HDL concentrations
    -Advantages are independent of gains in strength and muscle mass
  48. 48Does protein intake with resistance training affect older adults?-Protein intake immediately following resistance training with older adults results in greater muscle growth
    -This 'window of opportunity' is particularly important for elderly
    -Older muscle more nutrient resistant and exercise help with nutrient uptake
  49. 49Characteristics of exercise to benefit bone health-Site specific
    -Weight-bearing or resistance in nature
    -Dynamic & varied
  50. 50Exercise goals for osteoporosis-Improve muscle strength & endurance
    -Improve balance and stability
    -Maintain/enhance mobility & quality of life
    -AVOID: resisted, repeated or sustained trunk flexion, resisted abduction or adduction of leg, high impact aerobics
  51. 51What are the 6 classes of nutrients?-Carbohydrate
    -Fat
    -Protein
    -Vitamins
    -Minerals
    -Water
  52. 52What are the nutritional factors associated with exercise-induced fatigue?-Glycogen depletion
    -Hypoglycemia
    -'Central' fatigue
    -Dehydration
    -Hyponatraemia (low blood sodium)
  53. 53Why is dietary carbohydrate essential for athletes?-Muscle glycogen is unique fuel, used both aerobically and anaerobically
    -Fat can only be used with oxygen
  54. 54How many carbohydrates should athletes consume?-To maintain glycogen stores, CHO should be 50% of total calories/day
    -Those in heavy training and engage in endurance exercise should consume 55-60%
    -e.g. 3000 cal/day = 1650-1800 calories CHO
  55. 55Why should CHO intake be a percentage and not a exact quantity?-%'s need to be balanced against total energy intake
    -Athletes who consume large amounts of energy/day may meet their max rate of glycogen resynthesis with CHO respresenting only 40% of total energy
  56. 56How long does it take for replenishment of glycogen stores after exercise?-High carb diet: 24hrs
    -Low carb diet: attrition over 3 days
  57. 57What is the purpose of pre-exercise glycogen 'loading'?-To 'super-compensate' or max. muscle glycogen stores
    -Delay fatigue & allow maintenance of exercise at mod-high intensity for longer
    -We
  58. 58What does effect does pre-event (<4hrs pre-event) intake of CHO have?-Max muscle glycogen stores
    -Max liver glycogen stores
    -Ensure athlete is adequately hydrated
    -Prevent hunger but avoid gastrointestinal discomfort
  59. 59What is Glycaemic Index and what effect does it have on performance?-GI: speed glucose appears in blood
    -Low GI meals result in slower rise in blood glucose response
    -There is a significant difference in performance between high & low GI meals consumed before exercise
  60. 60What are the priorities during prolonged exercise?-Substrate replacement (prevention of hypoglycaemia and sparing muscle glycogen): will delay fatigue
    -Fluid replacement
  61. 61Does CHO intake during exercise have any effect? ('Central' influence)-Can improve mental performance as well as exercise capacity
    -Improve performance independent of glycogen depletion - suggesting a central (CNS) effect
  62. 62What role does fat play in the body?-Essential component of cell membranes & nerve fibres
    -Primary energy source
    -Protects organs
    -Stores the fat-soluble vitamins
    -Necessary for steroid hormone production
    -Provides insulation
  63. 63How is fat used during exercise?-Fat represents the largest fuel reserve for muscles
    -Fat transported by blood from adipose cells can be used by muscles, as can fat stored within muscle cells themselves
  64. 64Benefits of High Fat Low CHO diet-Results in adaptations in muscle that favour oxidative phosphorylation
    -Improved aerobic capacity in the muscles can reduce the rate at which muscle glycogen is used, delaying athlete hitting the wall
  65. 65Limitations High Fat Low CHO diet-Limitations related to potential to undertake high exercise intensity
    -For an endurance athlete in training, exercising for a couple days/wk on low CHO diet may be of value
  66. 66What is the role of protein?-20 AA required, 8 essential must be gained from diet (not created)
    -AA & protein contribute to structure, transport, enzyme function, hormone production, immune function, acid-base balance, fluid balance & energy availability
  67. 67Explain the term Biological Value-Measure of proportion of absorbed protein from a food which becomes incorporated in the proteins of body
    -How readily the broken down protein can be used in protein synthesis in the cells of the organism
    -raw egg = 100
  68. 68How much protein should athletes consume?-Well trained endurance athletes 1.2-1.6g/kg/d
    -Low-mod endurance exercise does not require any more protein than recommendations for sedentary individuals
    -Balanced diet will generally reach this
  69. 69Are all high quality proteins the same?-No: full cream milk >influence on muscle protein synthesis than fat-free milk (due to difference in total energy
  70. 70What is whey protein?-Whey protein elicits greater initial rate of protein synthesis than casein
    -Soluble protein quickly absorbed, casein clots in stomach - leading to slower absorption
    -Higher leucine content: possibly related to faster protein synthesis
  71. 71What does leucine & other essential AA do?-Stimulates protein synthesis; 6g will initiate synthesis; >20g no increased effect
    -Insulin response to EAA intake & insulin = AA's are together important for increasing protein synthesis
  72. 72Is it the amount or timing of protein that has a greater effect?-Timing rather than absolute daily intake for important for athletes seeking hypertrophy
    -No adverse health consequences with high protein intake
    -Supplementation with specific AA (e.g. glutamine) does not confer any benefit
  73. 73How should fluid be consumed during competition?-Fluid intake in events less than 30min duration will not benefit performance
    -For most endurance events (longer than 30 mins) fluid intake, especially when weather causes sweating, is beneficial
    -Change in body weight as result of prolonged endurance exercise can be 4kg (6% deficit in body water)
  74. 74How does fluid effect gastric emptying?-Maximising GE is important
    -High volumes of fluid can favour high GE
    -Keeping the CHO concentration of the sports drink below 6% will reduce the risks of lowering GE
  75. 75What is hyponatremia?-Condition where blood sodium conc/n lower than normal range 135-145mmol/L
    -Symptoms: weakness, disorientation, seizures & coma
    -Over-consumption of fluid during exercise can lead to hyponatremia & must be resisted
  76. 76Nutrition for recovery after training & competition-6-24hrs separate high intensity training sessions
    -Nutritional issues relating to recovery inc. restoration of muscle and liver glycogen, rehydration & repair/growth of tissue
  77. 77How does nutrition effect glycogen resynthesis?-Post-exercise muscle glycogen resynthesis is most rapid within 2-4 hours following exercise
    -B/c glucose enters the muscle cell independent of insulin
    -So, once exercise has been completed, CHO intake must immediately begin
  78. 78Fluid replacement due to exercise-Athletes only replace 30-60% of fluids lost
    -150% of volume lost needs to be consumed
    -Na conc/n need to be high to prevent post-exercise excessive urine loss
    -Sports drinks contain 10-25mmol/L of Na - not heaps but keeps palatable
  79. 79How is caffeine absorbed?-Absorbed by GI tract within 1hr
    -Peak plasma caffeine conc/n reached 15-20min after ingestion
    -Exreted in urine w/ half life of 3-5hrs
  80. 80When is caffeine taken by athletes?-Taken off banned list 2004
    -Taken 60min prior to exercise in doses equivalent to 6mg/kg
  81. 81How does caffeine affect the athlete's body?-Elicit ergogenic effect independent of glycogen sparing
    -Exercise improved in events lasting less than 30min
    -Improve Ca homeostasis in muscles & NaK-Pump
    -Strength/power & brief sprints
    -Increase reaction time but high doses impair fine-motor skills
  82. 82What are the side effects of consuming caffeine?-No adverse effects on sweating or body temp.
    -Diuretic effect has little evidence that a burden
    -Withdrawal effects of headaches / mood disturbances
  83. 83What is HMB?-Metabolite of leucine, made in body & in citrus & catfish
    -Not essential nutrient
    -Purported to reduce protein catabolism ->strength training over 3 wks (3d/wk) 3g/d. Suppl. increased muscle mass and strength
  84. 84How does HMB affect well-trained athletes and older people?-Well trained: HMB did not influence strength & LMB over 6wks
    -Does not influence reductions in strength associated with DOMS
    -HMB may benefit elderly & untrained
  85. 85What is glycerol?-Illegal substance
    -In hyperhydration, advantage to improved thermoregulation in heat
    -Glycerol suppl. stimulate ADH release, but been disputed in 2 studies
  86. 86How is the glycerol research disputed?-After glycerol ingestion, sweat rate was higher & cre temp. increased were lower
    -Equal number of studies showing no effect on HR, OT, sweat rate, RPE
    -1 study showed increased time to fatigue @ 60% VO2 Max after glycerol suppl.
  87. 87What are the risks of glycerol consumption?-Large intake could increase risk of cerebral & intraocular dehydration
    -Dizziness, nausea, bloating, vomiting & headaches possible
  88. 88What are alkalasing agents: sodium bicarbonate & sodium citrate?-Increase extracellular pH
    -Accelerate transfer of H+ from active muscle cells to blood, slowing intramuscular acidosis
  89. 89What is the research behind alkalising agents?-No obvious reason for disparity, may be nausea or training status
    -Max exercise causing fatigue around 1-2mins
    -300mg/kg bicarbonate, 500mg/kg sodium citrate
    -No sig. health problems
  90. 90What is the purpose of B-Alanine supplementation?-Improve muscle carnosine conc/n (which can buffer intramuscular H+)
    -8 wks of suppl. improves sprint performance
  91. 91What does research about B-Alanine state?-4 wks suppl. evokes sig. improvements to exercise capacity
    - As performance likely limited by accumulation H+ ions in skeletal muscle
    -4-6g/d 2+wks increases muscles carnosine content 20-30%, 40-60% wk4, 80% wk10
    -Dosage: 4.8g-6.5g/d
  92. 92What are the possible side-effects of B-Alanine supplementation?-Skin irritation
    -Flushing
    -Tingly sensation (paraesthesia)
    -Study showed after 4 wks non-toxicity & blood health markers normal
  93. 93Beetroot Juice as a supplementation-High in nitrate
    -Nitrate converted to nitrite then nitric oxide in body
    -NO is powerful vasodilator and associated w/ increasing blood flow to tissues such as skeletal muscle
  94. 94What effect does beetroot juice have on performance?-Reduces resting blood pressure & may improve mitochondrial function & muscle efficiency
    -Nitrate suppl. reduces O cost to both low-intensiy & high-intensity exercise
    -Rapidly absorbed & plasma levels peak 1hr after ingestion
    -Effective dose is 500mL
  95. 95What does research around beetroot suppl. say?-Mostly moderately trained subjects
    -300-500mL taken before exercise improves exercise capacity in endurance and sprint activities
    -No side-effects
  96. 96What is Glutamine?-AA: most abundant in muscle & plasma
    -Skeletal muscle is a major producer
    -Fuel for lymphocytes (key cells of immune system)

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