S2. Exercise at altitude Flashcards
What is a primary physiological limitation to exercise at high altitude?
VO2max is reduced due to hypoxia
How does pulmonary artery pressure change at high altitude?
It increases due to hypoxic pulmonary vasoconstriction
What is the impact of hypoxia on oxygen diffusion in the lungs?
It limits oxygen transfer due to reduced partial pressure gradients
How does high altitude affect cardiac output during exercise?
Cardiac output is maintained but stroke volume may decrease
What is the ‘Silver Hut’ expedition known for?
Studying human performance at extreme altitudes
What is a chronic adaptation observed in high-altitude populations?
Increased hematocrit and capillary density
What is the role of hypoxia-inducible factor (HIF) at high altitude?
It regulates gene expression for adaptation to hypoxia
How does mitochondrial density change with prolonged high-altitude exposure?
Mitochondrial density decreases
What is the ‘live high-train low’ approach?
Living at high altitude while training at lower altitudes to optimize performance
How does iron infusion benefit exercise at high altitude?
It reduces pulmonary artery pressure and improves cardiopulmonary function
What is the significance of bar-headed geese in altitude research?
They demonstrate superior oxygen transport and utilization in hypoxia
What are common metabolic changes observed at high altitude?
Switch to glycolytic metabolism and increased UCP3 expression
How does hypoxia affect pulmonary vascular remodeling?
It increases vascular resistance and pulmonary artery pressure
What effect does chronic hypoxia have on the right ventricle?
Increased workload and potential hypertrophy
How does high altitude impact VO2max?
VO2max decreases proportionally to the altitude level
What adaptation reduces the risk of hypoxic pulmonary edema in high-altitude natives?
Blunted hypoxic pulmonary vasoconstriction
How does acclimatization improve oxygen transport?
Increases red blood cell count and 2,3-DPG levels
What is the impact of hypoxia on peripheral oxygen diffusion?
It reduces oxygen delivery to tissues due to lower oxygen gradients
Why might athletes benefit from altitude training?
Improved oxygen delivery and erythropoiesis after returning to sea level
What is the purpose of control groups in altitude training studies?
To assess the true effects of altitude exposure on performance
How does prolonged hypoxia affect skeletal muscle?
Reduces oxidative capacity and shifts metabolism to glycolysis
What is a limitation of ‘living high-training high’?
It can impair high-intensity training performance due to hypoxia
How do chronic high-altitude populations differ genetically?
They have adaptations in HIF pathway genes for efficient oxygen use
What is the role of UCP3 in high-altitude metabolism?
It regulates mitochondrial uncoupling and energy efficiency
How does acute altitude exposure affect lactate production?
Increases due to a reliance on anaerobic metabolism
What is the significance of ‘Operation Everest II’?
A simulated study of human performance at extreme altitudes
How does pulmonary vasodilation impact exercise at altitude?
Improves oxygenation but may increase blood flow inefficiency
What is the effect of high altitude on blood oxygen saturation?
Decreased saturation due to reduced partial pressure of oxygen
Why is iron status important for altitude adaptation?
Iron is essential for hemoglobin synthesis and oxygen transport
What metabolic shift occurs in Phd1 knockout mice at altitude?
Improved adaptation to hypoxia with altered metabolism
What is the impact of altitude training on erythropoiesis?
Stimulates red blood cell production through EPO activation
What are the main ethical concerns with hypoxic training?
Potential unfair advantages and health risks
How does the heart adapt acutely to altitude?
Increased heart rate to maintain cardiac output
What is the effect of prolonged altitude exposure on muscle mass?
Muscle atrophy due to reduced protein synthesis
What is the role of PPARa at high altitude?
Regulates lipid metabolism under hypoxic conditions
How does exercise at altitude affect ventilation?
Ventilation increases to compensate for lower oxygen availability
What is the significance of studying Chuvash polycythemia?
It provides insights into adaptations to chronic hypoxia
Why is ‘dose’ of hypoxia important in training?
It determines the extent of physiological adaptations
What is the relationship between high altitude and oxidative stress?
Increased oxidative stress due to hypoxia and reduced antioxidants
How does high altitude affect capillary density?
Increases to enhance oxygen delivery to tissues
