Metabolic Rate Fitness Efficiency Human Metabolism Metabolic Rate Fitness Efficiency

Metabolism Internal energy comes from food Oxidation of food supplies energy Energy goes into Internal functions External work Excess expelled as heat Rewrite in terms of rates U/t < 0 Must replenish U with food The metabolic rate (U/t) is the rate at which food and oxygen are converted to internal energy to balance loss through Q & W

Metabolic Rate Metabolic Rate directly proportional to volume of oxygen consumed U/t in kcal/s VO2/t in L/s Can measure VO2/t to determine metabolic rate Can measure W/t to determine power output Use to find efficiency

Basal metabolic rate is the rate when sleeping Metabolic Rates p. 415 Basal metabolic rate is the rate when sleeping

Physical (“Aerobic”) Fitness Aerobic fitness is a measure of a person’s maximum capacity to use oxygen Increases with exercise Decreases without p. 416

Efficiency Body does work  can function as a machine Define efficiency as before Affected by the type of work done p. 416