Describe the acute effects of high altitude on the cardiovascular and respiratory systems

Decreased partial pressure of O2 in the air means that the diffusion gradient between the alveoli and surrounding capillaries is reduced. Hence there’s a decreased haemoglobin and oxygen association in the blood so decreased oxygen transport to the working muscles. Hence less oxygen is available for aerobic energy production. Resulting in increased breathing frequency and heart rate and decreased stroke volume. So the performer will have a decreased VO2max, aerobic capacity, intensity and duration of aerobic performance before fatigue sets in.