Lab 1 - Critical Power Flashcards
What is critical power?
- highest power output which can be sustained indefinitely
- in reality, it cannot actually be sustained indefinitely due to a few other factors (glycogen depletion, hyperthermia, dehydration etc…)
What occurs if the power output is above critical power?
- metabolic by-products accumulate until exhaustion is reached
Power-time relation equation
T exhaustion = W’/(PO-CP)
- W’ = curvature constant (equivalent to a fixed amount of work that can be performed above CP)
- therefore, exercise is tolerated until W’ reaches 0
- the further above CP that work is being done, the faster W’ is reduced resulting in shorter T exhaustion
Linear version of the Power-time relationship equation
PO = [ W’ (1/T exhaustion)] + CP
Y-intercept = CP
Slope = W’
- idk how important this equation is but just in case
Equation for Critical speed- time relationship
Distance = (CS x time) + D’
CS = critical speed which acts the same as critical power
ie. below critical speed you can technically go on indefinitely, but above it fatigue will be reached depending on how high above it you are
D’ = finite distance that can be covered above critical speed (same as W’ but instead of certain amount of work performed its a certain distance that can be achieved before fatigue)
Is steady-state achieved if cycling at CP?
Yes
- according to study, VO2 and blood [lactate] reached a delayed steady state, whereas above CP, they keep rising until exhaustion
What has been concluded about exercise above CP through numerous studies? (3 points)
- VO2 never reaches a steady state but progressively increases until VO2 max
- exponential fall in muscle [PCr] and [glycogen], indicating increase in reliance on substrate level phosphorylation
- progressive accumulation of metabolites like lactate, H+, ADP, and Pi, which contribute to the development of fatigue in the muscle
