chapter 1 Physiology of Aerobic Anaerobic Exercise Introduction
chapter 1 Physiology of Aerobic & Anaerobic Exercise Introduction to Nutrition for Exercise and Prof Jennifer Broxterman, RD, MSc Health FN 3373: Nutrition for Physical Activity Lecture 2 Author name here for Edited books
What Fuels Physical Activity?
ATP
Hydrolysis of ATP
ATP & Energy Use by Exercising Muscles
Rephosphorylation of ADP to Form ATP
Energy Systems that Replenish ATP Creatine Phosphate Anaerobic Glycolysis Oxidative Phosphorylation ATP
Characteristics of the 3 Energy Systems Speed of Action Creatine Phosphate Anaerobic Glycolysis Oxidative Phosphorylation Amount of ATP Replenished Very Fast Very Small Duration of Action Very Short Fast Small Short Very Slow Large Very Long
Energy System 1 Creatine Phosphate
Creatine Phosphate Energy System
The Cr. P Energy System Rephosphorylates ADP to ATP Rapidly • Anaerobic reaction • If [ATP] in a muscle ↓ there is an accompanying ↑ in ADP in the cell – ↑ in the activity of CK, allowing the reaction to proceed faster • Cr. P is stored in very small amounts • At very high-intensity exercise it takes ~ 5 -10 seconds for Cr. P in the muscle to be depleted and fatigue to set in
Characteristics of the Cr. P Energy System • • One chemical step Catalyzed by creatine kinase (CK) Very fast reaction One ATP per Cr. P molecule 5 -10 second duration Anaerobic Fatigue associated with Cr. P depletion Predominant energy system in very highintensity exercises (power events)
Creatine Phosphate & ADP Rephosphorylation
The Creatine Shuttle
Energy System 2 Anaerobic Glycolysis
Glucose GLYCOLYSI S 2 ATP 2 Pyruvic Acid molecules Aerobic Metabolism CO 2 + H 2 O If Oxygen is Present 36 -38 ATP If Oxygen is Absent Anaerobic Metabolism Lactic Acid
The Anaerobic Glycolysis Energy System
Anaerobic Glycolysis
Cori Cycle
Energy System 3 Oxidative Phosphorylation
Glucose GLYCOLYSI S 2 ATP 2 Pyruvic Acid molecules Aerobic Metabolism CO 2 + H 2 O If Oxygen is Present 36 -38 ATP If Oxygen is Absent Anaerobic Metabolism Lactic Acid
Cellular Respiration Overview C 6 H 12 O 6 + 6 O 2 (glucose) 6 CO 2 + 6 H 2 O + Energy (heat and ATP) • The energy in one molecule of glucose yields 36 ATP • Aerobic respiration involves a series of 3 reactions: – Glycolysis – Krebs Cycle – Electron Transport Chain
Glycolysis
Oxidative Phosphorylation Energy System
Glycolysis, Krebs Cycle, Electron Transport Chain of Oxidative Phosphorylation
Macronutrients as Fuel Sources during Exercise
Beta Oxidation
Respiratory Exchange Ratio
Respiratory Exchange Ratio
Respiratory Exchange Ratio
RER Chart
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