Lecture 9 Flashcards
Performance tests assumptions:
All ATP at maximal power output regenerates via ATP-PCr hydrolysis
Enough STP and PCr exists to support maximal performance for ~ 6 seconds*
Power test measures…
Brief, maximal E capacity
P = F x D / T
Anaerobic system changes with training:
Increases in resting muscle levels of ATP, PCr, free creatine , Glycogen, glycolytic enzymes
Resulting in increase capacity to generate blood lactate
Creatine (Cr)
Nitrogenous organic acid that occurs naturally in vertebrates and helps to supply energy to muscle
~50% of stored Cr originates from…
food (mainly fresh meat)
~50% of the daily Cr is biosynthesized…
from amino acids. The rest is taken in by alimentary sources
~95% of Cr is later stored…
in the skeletal muscles
Phosphocreatine (PCr)
Aka creatine phosphate
Phosphorylated creatine molecule that is an important energy store in skeletal muscle and in the brain
PCr formed from…
Parts of 3 amino acids – Arg, Gly, Met
PCr is synthesize in…
The liver
PCr is transported to…
Muscle cells, via the bloodstream, for storage
Theoretical premise behind Cr supplementation
1 increase intramuscular stores of Cr may maintain high cellular ATP/ADP rations
2 PCr acts to buffer accumulating protons (H+), which may enable to continuation of maximal exertion
3 Cr may facilitate energy translocation from the mitochrondra to the various sites of ATP utlisation by a process termed the PCr energy shuttle
Cr supplementation & ex performance:
Benefit repeated, short bouts of high-intensity ex
Men/women/young/old
Training status may impact Cr uptake
Effects of chronic supplementation unknown
Side effect: retain fluid – increase body mass
In interval sessions of 10s work, 25s is…
The minimal time of recovery at which no blood lactate accumulates with multiple efforts
PCr largely depleted in…
- 10s of maximal ex (50%) drop off
PCr recovery
5-6 s maximal effort PCr degradation accounts
PCr contribution to repeated sprints depends on whether the PCr stores are given the time to replenish
PCr replenishment depends on…
O2 availability
