Exercise Physiology 6 - use lecture graphs

winniesmith2's version from 2017-12-30 11:32

Section 1

Question Answer
power/velocity vs durationstart at max power and see how long they can maintain it for. then after resting period, repeat again at lower intensity each time,measuring time they can maintain it for until you get to the power they can maintain for 20/30mins.
what is critical power (CP)Highest power output that can be maintained over time. homeostasis is key, can only be maintained if kept in equilibrium.
What is critical power related to?maximum lactate steady state.
What does W prime show anaerobic energy store
how do you calculate W prime'supra-CP work rate' (higher than CP) X duration. W= Power (w) X time (s)
What does the area above CR represent Fixed energy store that mainly represents anaerobic capacity. Anaerobic energy store.
Fixed energy store that mainly represent anaerobic capacity; what contributes. – PCr, glycolysis (->lactate) – Small contribution from myoglobin and haemoglobin-bound O2 stores. – Once depleted / speed of required energy production exceeded -> exhaustion – However, fatigue-related products may contribute, too (for example, H+)
Athlete A can maintain a power output of 600 W for 30 s, and his/her CP has been estimated at 300 W. How long will this athlete be able to exercise at 400 W?W'= 300W x 30 s = 9000j. 9000j/100w=90s
Athlete A can maintain a power output of 620 W for 30 s, and the CP has been estimated at 300 W. Athlete B can maintain a power output of 500 W for 45 s, and the CP has been estimated at 280 W. Which athlete will win a time trial over 40 km?trick. time trial- W' not really important. Athlete A has a higher critical power so A would win.
Critical power- practical applications • Characterisation of athletes: what is highest sustainable power? • Power zones: training prescription • Athlete tracking over season / training cycle
Low intensity domain Below the LT; BLa < 2 mmol/L; < 70 % Vሶ O2max; steady state in < 3 min
Moderate domain Between the LT and the MLSS / critical power; BLa elevated but stable at 2 to 8 mmol/L; 70-90 % Vሶ O2max; steady state delayed.
Severe domain (interval): Above the MLSS ; critical power; BLa > 2-8 mmol/L; > 90 % Vሶ O2max; steady state not attainable.

Section 2

Question Answer
What is oxygen uptake kinetics • Breath by breath analysis of oxygen uptake • Oxygen uptake kinetics differ for different exercise intensities and can help to define domains of exercise!
oxygen uptake kinetics; 3 distinct phases 1- blib in graph. 2- steep increase. 3. levels out
Phase 1 cardiodynamic component (~20 s) – Transit time of blood from the exercising muscle to the lungs
Phase 2 primary component (~2-3 min) – Pulmonary Vሶ O2 rises in a mono-exponential fashion to meet the muscle oxygen demand
Phase 3slow component (> 3 min) – Slow rise in Vሶ O2
Oxygen uptake kinetics phase 3- why do we have this stage• Crucial phase to distinguish domains of exercise • At higher power outputs, fast motor units (type II fibres) have to be recruited – more force can be generated – not as efficient and fatigueresistant as Type I fibres  more oxygen needed per unit of force
Exercising above the lactate threshold results in a steady state of oxygen uptakeit depends.
Moderate exercise (below lactate threshold, LT)• Phase II: monoexponential increase in Vሶ O2 • Phase III: none
Heavy exercise (between LT and CP)• Phase II: monoexponential increase in Vሶ O2 • Phase III: slow component
Severe exercise (above CP)• Phase II mono-exponential increase in Vሶ O2 • Phase III “slow component” never stabilises and continues until exercise has to be terminated or Vሶ O2 max is attained
Athlete A has a critical power of 300 W. Do you expect to observe a slow component (Phase III) in Athlete A’s oxygen uptake kinetics at 250 W?it depends- we would need to know if it was above or below lactate threshold.