Aerobic Exercise Response 5 Aerobic Exercise Response Respiratory Quotient (RQ)/ Respiratory Exchange Ratio (RER) RQ - The ratio of the amount of carbon dioxide produced divided by the amount of oxygen consumed at the cellular level RER - The ratio of the volume of carbon dioxide produced divided by the volume of oxygen consumed on a total body level RQ = VCO2/VO2 Metabolic System Unit Copyright © Pearson Education, Inc. publishing as Benjamin Cummings

RER CHO (per molecule of glucose) 6 O2 + C6H12O6 = 6 CO2 + 6 H2O + 36 – 38 ATP RER = 6 CO2/6 O2 = 1.0

RER FAT (molecule of palmitic acid) C16H32O2 + 23 O2 = 16 CO2 + 16 H20 +129 ATP RER = 16 CO2/23 O2 = .70

RER The RER at rest is ~ .78 - .80.

Table 5.4 Copyright © Pearson Education, Inc. publishing as Benjamin Cummings

Table 5.5 Copyright © Pearson Education, Inc. publishing as Benjamin Cummings

Aerobic Exercise Response 5 Aerobic Exercise Response Caloric Equivalent - The number of kilocalories produced per liter of oxygen consumed Caloric Cost - Energy expenditure of an activity performed for a specific period of time Metabolic System Unit Copyright © Pearson Education, Inc. publishing as Benjamin Cummings

Aerobic Exercise Response 5 Aerobic Exercise Response Caloric cost (kcal/min) = O2 consumed (L/min) x caloric equivalent (kcal/LO2) Given: RER = .91 O2 cons = 2.15 L/min Calculate caloric cost for 30 min of exercise Metabolic System Unit Copyright © Pearson Education, Inc. publishing as Benjamin Cummings

Aerobic Exercise Response 5 Aerobic Exercise Response The caloric equivalent for an RER of .91 is 4.936 kcal/LO2 (see table 5.4) 2.15 O2/min x 4.936 kcal/LO2 = 10.61 kcal/min 10.61 kcal/min x 30 min = 318.3 kcal Metabolic System Unit Copyright © Pearson Education, Inc. publishing as Benjamin Cummings

Aerobic Exercise Response 5 Aerobic Exercise Response The Metabolic Equivalent (MET) MET - A unit that represents the metabolic equivalent in multiples of resting rate oxygen consumption of any given activity MET = O2consumed/3.5 Metabolic System Unit Copyright © Pearson Education, Inc. publishing as Benjamin Cummings