ESS 3091- 5- Exercise Metabolism- Student-2

Fog vs so fibers capacity to shuttle nadh to

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Unformatted text preview: ent of FG vs. FOG vs. SO fibers Capacity to shuttle NADH to mitochondria Build-up of NADH in cytoplasm: ↑ fast glycolysis Lactate Threshold = Lactate entry (production) >> Lactate removal (oxidation) ◦ The inflection point that suggests the shift towards predominantly fast glycolytic ATP synthesis Progressive ↑ in lactate prior to LT, exponential ↑ in lactate @ LT ◦ ~50% VO2max untrained ◦ ~75% VO2max trained Lactate • Training= Delayed shift from oxidative to nonoxidative mechanisms ◦ greater oxidative capacity Greater efficiency of lactate shuttles (“lactate consumer”) Exercise Intensity & Fuel Selection As exercise intensity increases there is greater reliance on CHO and reduced reliance on FAT ◦ ↑ blood epinephrine levels ◦ SO → FOG → FG fiber recruitment Oxidative → Non-oxidative pathways ↓ O2 availability ↓ opportunity for oxidative mechanisms Exercise Intensity & Fuel Selection Respiratory exchange ratio (RER) ◦ = VCO2/VO2 ◦ 1.0= CHO ◦ 0.7= FAT RER RER > 1.0 w/ high intensity, NON- steady state exercise H+ from HLA, ↑ NADH + H+ production (↑ATP use) Bicarbonate buffering system: Expired at lungs= ↑CO2 part of RER VCO2/ VO2 Fuel for Exercise During short duration, graded exercise, CHO use ↑ & FAT use ↓ as...
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This document was uploaded on 03/26/2014.

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