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

PO2 = 100

Respiration

PO2 = 100PCO2 = 40

7

PO2 = 40

Pulmonary Respiration

Cellular Respiration

Oxygen Saturation

Sea level = 97%

Saturation

Mount Everest = 48%

Saturation

The Pulmonary System & Exercise

Control of Ventilation

CO2 CO2

Ventilation & Steady State Exercise

Ventilation & Graded Exercise

Note the non-linear

Note the non-linear

increaseincrease

in ventilation

in ventilation

Ventilation Threshold

CO2 from Krebs cycle stimulates

ventilation

CO2 from Krebs cycle and

buffering lactic acid stimulate

ventilation even faster

Aerobic Aerobic andAnaerobic1

3

Ventilatory & Lactate Thresholds

Exercise “Talk Test”

3 4 5 6 7 8 9 10 11 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

InspirationDiaphragm (rest and

exercise)External intercostal

muscles (exercise)Others (exercise)

ExpirationInternal intercostal

muscles (exercise)Abdominal muscles

(exercise)

Pulmonary Diseases

• Exercise induced asthma

• Chronic obstructive lung disease (COPD)