BIOD43H3 Lecture Notes - Lecture 21: Exercise Intensity, Evaporative Cooler, Vasodilation
BIOD43 Lecture 21: Biotic and Abiotic Influences on Exercise
Exercise in cold requires higher performance to up metabolis, and produce more heat
• Exercise in cold leads to higher VO2 ventilation, this can problematic because it leads to:
-Great heat loss
-Increase sympathetic stimulation= greater glycogen use, and less lipid
-Peripheral vasodilation = lower HR
-Less blood flow to adipocytes
-Decrease muscle enzyme activity
• Heat and Exercise
- Evaporative cooling occurs through sweating
ex. Eccrine glands are a sympathetic response and Apocrine glands is sweat produced
from under arm and genital areas, which gets secreted from lipid when bacteria
-Sweating rate is influenced by blood flow
-Nitric Oxid causes local vasodilation
• Sweat from athletic is generally less smelly that sweat from nervous people
• Exercise in the Heat
- The core temperature at relative exercise intensity is consistent
I ar teperature ou reah aiu ore teperature ith loer asolute
exercise intensities. This limits performae leels
-Increased peripheral vasodilation = TPR and Heart Rate, which is less effective at higher
exercise intensity.
-At highest exercise intensities, vasoconstriction occurs at surface to save blood flow too
active tissue.
• Habituation: less of a response (sensation activation) associated with outside influence
-In cold, less shivering to allow better function (ex. Can not sleep well if shivering all the
time)
-In heat, less sweating during early exposure to increase in core temperature
• Acclimatization to temp in ectotherms
-membrane viscosity related to temperature
-more membrane viscosity, potentially faster transport, but too viscous is also not good.
• Ice fish in polar ice salt water, have better LDH functions when Km value is at -1.9
degrees.
• Poiseuille’s La: Q=(P1-P2) pi r4/ 8Ln; CO= HR x SR, the rise in CO is due to rise in HR.
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