To examine the relationship between clinical workload and aerobic fitness.
Twenty healthy intern and resident volunteers were studied in a cross over manner to compare their aerobic fitness after a 1 month "easy" clinical rotation (ECR) to that after a 1 month "hard" clinical rotation (HCR). The ECR and HCR were prospectively estimated as requiring 70 (HCR) total hours per week of hospital work respectively. Aerobic fitness was determined by directly measuring peak oxygen uptake (peakVO2) during peak cycle exercise testing after each rotation. Clinical workload for the month preceding the exercise test was estimated by documenting the amount of hospital work and sleep lost because of on-call duties. The average weekly amount of effective aerobic training for each rotation was also documented.
Trainees had a 206.4 (P = 0.0019, 95% CI 94-318.8) mL/min or 3 mL/kg/min (P = 0.0019, 95% CI 1.5-4.4) improvement of peakVO2 after the ECR compared with the HCR. Trainees averaged 1 (95% CI 0.16-1.81) less hour per week of exercise training, 34.1 more hours per week of hospital work (95% CI 23.0-45.3, P