Energy Metabolism Flashcards
Factors determining fuel source
Exercise intensity
Exercise duration
Level of training
Composition of diet
Four major fuel sources
Muscle glycogen
Plasma glucose
Intramuscular triglycerides
Plasma free fatty acids
Where is phosphocreatine stored
Skeletal muscle
In ______________ metabolism, pyruvate converts to ______ and results in what 4 things
Lactate
Results in a drop in muscle pH
Reduce enzyme activity for glycolysis
Results in skeletal muscle fatigue
Lactate enters the Cori cycle
In _______ metabolism, glucose is oxidated to _________ and condenses with __________ to enter what cycle
Aerobic
Acetyl CoA
Oxaloacetate
Krebs
Explain what hemoglobin is/does
Molecule in the blood responsible for transport of oxygen to the working muscles
Explain what myoglobin does
Accepts the exchange of oxygen from hemoglobin and delivers it to the mitochondria for use in aerobic metabolism
Cardiovascular adaptation to endurance training
Increased cardiac output, blood volume, heart rate, blood pressure, and type 1 muscle fibers
Increased mitochondria, oxidative enzymes, and myoglobin content
What is the fuel source for
High intensity (85% VO2 max) lasting less than 1 minute
High intensity lasting 4-5 minutes
Moderate intensity
Low intensity (</= 65% VO2 max), very long duration >6 hours
High intensity (<1 min)
100% ATP PC for the first few seconds
Then ATP/PC and anaerobic glycolysis
High intensity (4-5 min)
ATP/PC (6%)
Anaerobic glycolysis with lactic acid build up (94%) - due to lack of oxygen availability
Moderate intensity
Predominantly aerobic metabolism (carbs)
Fat (intramuscular triglycerides and plasma free fatty acids) contributes as well
Low intensity (>6 hours)
Predominantly fat oxidation in the latter stages with contributions from aerobic glycolysis
Signs of overtraining
Performance declines regardless of continued training
Loss of muscle and endurance capacity
Fatigue
Chronic muscle soreness
Difficulty concentrating, decreased motivation, and increased depression
Decreased appetite
Loss of weight and/or body fat
Increased anxiety, restlessness, and poor sleep quality
How to resolve overtraining
Reverse with proper training
Rest
Proper nutrition (especially carbohydrates, protein, and hydration)
Who is most at risk for micronutrient deficiencies
Athletes that restrict energy intake
Athletes that have limited variety in their food
Athletes that train more than 20 hours/week
What fuel system would be used in the following scenario:
You see the finish line and are neck and neck with the runner beside you so you break into an all out sprint to the finish
Anaerobic glycolysis with lactate buildup
List the ranges for activity factors
Sedentary (1.1-1.39)
Lightly active (1.4-1.59)
Moderately active (1.6-1.89)
Very active (1.9-2.5)
In ____________ metabolism, glucose converts to ________
Anaerobic
Pyruvate
