Exercise Physiology — MCQs

A 42-year-old firefighter candidate undergoes VO2 max testing showing 32 mL/kg/min (below required 42 mL/kg/min). His body composition shows 28% body fat. He has normal cardiac function (ejection fraction 60%), hemoglobin 15.2 g/dL, and no respiratory disease. Lactate threshold occurs at 65% of VO2 max. Evaluate the most effective evidence-based training strategy to meet occupational requirements within 12 weeks.

A 38-year-old woman with mitochondrial myopathy due to a complex I deficiency presents with severe exercise intolerance. Her baseline lactate is 3.2 mmol/L (normal <2.0) and rises to 12.8 mmol/L after minimal exercise. Her VO2 max is 18 mL/kg/min. Cardiopulmonary and hematologic evaluations are normal. Evaluate the pathophysiologic mechanism and optimal exercise approach.

A 40-year-old man with chronic heart failure (ejection fraction 30%) undergoes cardiopulmonary exercise testing. His peak VO2 is 14 mL/kg/min with a respiratory exchange ratio of 1.18, indicating maximal effort. His predicted VO2 max is 35 mL/kg/min. Analyze the primary physiologic limitation to his exercise capacity.

A 32-year-old competitive cyclist develops unexplained fatigue during training. Laboratory studies show hemoglobin 11 g/dL (normal 14-18), serum ferritin 8 ng/mL (normal 30-300), and elevated erythropoietin. His VO2 max has decreased from 65 to 52 mL/kg/min over 3 months. Analyze the relationship between his hematologic findings and exercise capacity.

A 50-year-old obese man begins high-intensity interval training (HIIT). During sprint intervals, his respiratory exchange ratio (RER) reaches 1.15. His minute ventilation is 120 L/min with VCO2 of 4800 mL/min. Apply these findings to determine his oxygen consumption rate during the sprint.