Physical activity Flashcards
Energy metabolism
Catabolism of glucose, fatty acids, amino acids, or alcohol
Energy stored in C - H bonds is captured in ATP
Glucose energy
Anaerobic: glycolysis (glucose oxidation) splits glucose molecule to form 2 pyruvate molecules
Forms small amount of ATP
Aerobic: oxidizes glucose, pyruvate enters aerobic respiration pathways
Three major energy systems
Phosphocreatine (PCr) = anaerobic
Lactic acid - anaerobic
Oxygen - aerobic
Lactic acid energy
ANAEROBIC
Glucose –> pyruvate –> lactic acid
Forms enough ATP for 30 - 40 seconds
Lactic acid releases hydrogen ions and becomes lactate, which enters the bloodstream
Oxygen energy system
During aerobic conditions, muscle cells completely metabolize glucose and produce 18X more ATP
Aerobic Capacity
VO2 Max: maximal oxygen intake during vigorous physical exertion
Fat or Carb fuel?
Fat: when at rest/during low/moderate intensity activity
Carbs: high-intensity
Protein: small amount during endurance exercise
Carb Loading
CHO loading
Manipulate physical activity/dietary patterns before an athletic event to increase muscle glycogen stores