1. Oxygen Uptake Oxygen Debt Oxygen Deficit

2. Oxygen Uptake
During exercise there is increased activity in skeletal muscle requiring ATP to enable muscle contractions for the duration of the activity.
As a consequence of the physical activity ACUTE RESPONSES occur in the body.
Acute Responses = a short term physiological response to a condition or exercise that is followed by a return to pre-exercise levels once the condition is removed or stopped.
The nature of the acute responses depends on; which muscles are being used, the intensity, duration and type of activity undertaken and how much muscle mass is involved.
In response to the increasing intensity of exercise, oxygen intake, transport, extraction and consumption all rise.
There is a linear relationship between the amount of oxygen taken up and the intensity of exercise and it occurs until the maximum levels of oxygen uptake are reached (VO2 Max)

4. Oxygen Intake
Pulmonary Ventilation
Diffusion of Oxygen from lungs to blood
Oxygen Transport
Cardiac Output
Blood flow to muscles
Uptake of oxygen by skeletal muscle Myoglobin
Oxygen Uptake
Oxygen used in the muscle fibre Mitochrondria
Oxygen Consumption

5. Oxygen Deficit
As the body moves from rest to exercise involves some time where the bodies demand for oxygen exceeds the supply available.
The acute circulatory and respiratory responses cannot act quickly enough to satisfy the demand for oxygen.
Oxygen Deficit = the period after the onset of exercise where oxygen consumption is below the required to produce all the ATP needed aerobically.
Whilst in oxygen deficit, the body can continue to exercise by obtaining ATP anaerobically.

6. When the body works at high intensity for a short duration, there is no abundance of oxygen, so lactic acid cannot be broken down quickly.
Once the performance becomes predominantly aerobic in nature, STEADY STATE has been attained so lactic acid accumulation ceases.
Steady State = the point during exercise when oxygen supply equals oxygen demand.
Answer the following questions:
Explain why an oxygen deficit occurs in physical activity.
As exercise becomes more intense, the demand for ATP continues to rise and the supply of oxygen is insufficient. Identify the consequence of this for the body.

7. Oxygen Debt
At the completion of physical activity, the demand for ATP decreases, but the amount of oxygen required still remains above the amount required at resting levels.
Oxygen Debt = the volume of oxygen used during recovery from exercise in excess of resting oxygen consumption.
The increased oxygen consumption can last for a period of minutes or hours after physical activity and is necessary for recovering from exercise.
The size of oxygen debt is proportional to the intensity and duration of the activity undertaken.
Respiration rate and HR will remain elevated to enable higher oxygen consumption.

8. Another term used for Oxygen Debt is; Excess Post-exercise Oxygen Consumption (EPOC)