App Phys week 1

bethdrysdale94's version from 2017-01-26 15:56

Section 1

Question Answer
What is a linear event?sustainable or constant event eg marathons/cycling. a-linear = football, boxing etc
When does exercise intolerance result?unable to sustain work-rate sufficiently for successful completion eg fatigue.
What determines fatigue?exercise tolerance
What is exercise performance dependent on?integrated functioning of physiological systems, O2 ---> mitochondria essentially
When is exercise sustainable?When the demand of O2 transport can be met at a steady state, otherwise we rely on anaerobic processes that lead to fatigue
What is the definition of power?the rate at which ATP can be produced
What is the definition of capacity?how much ATP can be produced (available energy)
In simple terms, how does anaerobic resp lead to fatigue?production of lactic acid > lactate and H+ ions > H+ ions reduce enzyme performance and lead to acidosis
What substances are used during anaerobic resp and why are they limiting?phosphocreatine (PCr) and anaerobic glycolysis. - few stores available, low capacity despite high power. an. glycolysis can be inhibited by H+
What substances are used during aerobic resp and what are their strengths/limitations?Aerobic CHO and aerobic FFA. large capacity so unlikely to run out however power isnt very efficient.

Section 2

Question Answer
What is lactate threshold 1?1mmol of lactate above baseline - also known as ventilatory threshold, gas exchange threshold
What is OBLA?Onset of Blood Lactate Accumulation - 4mmol, set value
What is OBLA also associated with?aka Lactate threshold 2, associated with critical power. (maximal lactate steady state)
What is Critical power? (CP)reflects highest power output (constant) that can be maintained without progressive loss of homeostasis (maintenance of VO2, pH, lactate)
How is CP plotted on a graph?power to duration relationship, negative correlation curve
What is W prime?product of supra-CP work-rate and exercise duration. > has units of energy (J) > fixed energy store representing the anaerobic capacity and once depleted, leads to exhaustion
How do you calculate a linear equation for CP?divide 1 by each time measure - fit a straight line through data - y=mx + c >>> c is the point at which the line crosses the y axis and is equivalent to CP value in watts

Section 3

Question Answer
How is oxygen uptake response characterised between rest and exercise?Phases: 1, 2 & 3. 1 - 0-20 secs. 2 - 40-90 secs. 3 - critical after 2-3 minutes
What is Phase 1 of the oxygen uptake response?transit time of blood from exercising muscles to lungs
What is Phase 2 of the oxygen uptake response?pulmonary VO2 rises in mono-exponential fashion, reflecting muscle VO2
What is Phase 3 of the oxygen uptake response?steady state or slow component
Characteristics of low intensity exercise normal curve, reaches steady state (phase 3)
Characteristics of medium intensity exercisenormal curve but drifts above steady state and into a slow component (continually increasing but very gradually)
Characteristics of higher intensity exercisethe "slow component" never stabilises and continues to rise until exercise is ceased or VO2 max is attained
Characteristics of very high intensity exerciseincrease rapidly until VO2 max is reached
exercise below Lactate thresholdreaches a steady state - moderate
exercise below CP/maximum lactate steady state but above lactate thresholdslow component can mostly be maintained for around 1 hour - heavy
exercise below VO2 max but above CP/MLSShomeostasis goes pearshaped, cant last and will reach VO2 max - very heavy
exercise above VO2 maxVO2 max will be reached rapidly - severe

Section 4

Question Answer
what are the exercise domains?moderate, heavy, very heavy and severe
What are the exercise domains delineated by?0-LT, LT-CP, CP-VO2 and VO2+
What is the confusion between zones and domains?domains are easily delineated, there are actually only 4 zones but these zones are often split and delineated using confusing and inaccurate values eg lactate

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