Responses and Adaptation to Altitude Exposure and Training

1. Responses and Adaptation to Altitude Exposure and Training

2. Altitude Exposure • O2% is same as sea level, but PO2 is  • Hypoxia drives cardiorespiratory system to maintain O2 delivery • Exercise VO2 remains the same, but % of VO2max  • Acute effects differ from chronic adaptations

4. Oxygen transport cascade

5. Responses to acute altitude exposure • O2 driving force •  length of time required to saturate Hb •  SaO2sat •  fluid loss •  catecholamine release •  TPR, BP •  VE • diminishes  PO2 •  PCO2 & H+ • leftward shift of HbO2 curve •  La response •  Qsubmax, •  VO2max

6. Chronic pulmonary adaptations to altitude exposure •  pulmonary capillarization •  VE •  CO2 release • leftward shift of HbO2 •  HCO3- secretion • rightward shift of HbO2 curve •  La response (from acute exposure) • La paradox

7. Chronic CV adaptations to altitude exposure •  RBC 2,3-DPG •  HbO2 binding strength • rightward shift of HbO2 curve •  PV •  SV, Q •  EPO ( at >10,000 ft) •  Hb, RBC, Hct •  mitochondria/enzymes

8. Catecholamine release changes with chronic altitude exposure

10. Altitude training adaptations •  training volume at altitude •  O2 transport, but  buffering capacities • n/c in VO2max at sea level