Respiration During Exercise

Terms Ventilation Respiration Pulmonary respiration Cellular respiration

Ventilation Respiratory Muscles Inspiration Diaphragm (rest and exercise) External intercostal muscles (exercise) Others (exercise) Expiration Internal intercostal muscles (exercise) Abdominal muscles (exercise) FYI

Structure of the Respiratory System Conducting Zone Respiratory Zone Alveoli

Respiration PO2 inside the venous blood = 40 PO2 inside the alveoli = 100 Therefore, O2 flows from the high pressure (lungs) to the low pressure (blood) PO2 inside the arterial blood = 100 PO2 = 40 PO2 = 100

Respiration PO2 = 100 PCO2 = 40 7 PO2 = 40 Pulmonary Respiration Cellular Respiration

Oxygen Saturation Sea level = 97% Saturation Sea level = 97% Saturation Mount Everest = 48% Saturation Mount Everest = 48% Saturation

The Pulmonary System & Exercise

Control of Ventilation CO 2

Ventilation & Steady State Exercise

Ventilation & Graded Exercise Note the non-linear increase in ventilation

Ventilation Threshold CO2 from Krebs cycle stimulates ventilation CO2 from Krebs cycle and buffering lactic acid stimulate ventilation even faster Aerobic Aerobic and Anaerobic 13

Ventilatory & Lactate Thresholds Exercise “Talk Test” mph

Ventilation & Exercise Does the pulmonary system limit exercise performance? Untrained - fatigue of respiratory muscles Trained - greater than 80% of max and longer than 10 min Exercise-induced hypoxemia

Training 20-30% decrease

Training Do the lungs adapt to exercise training? Do the respiratory muscles adapt to exercise training? Respiratory Muscles Inspiration Diaphragm (rest and exercise) External intercostal muscles (exercise) Others (exercise) Expiration Internal intercostal muscles (exercise) Abdominal muscles (exercise)

Pulmonary Diseases Exercise induced asthma Chronic obstructive lung disease (COPD)