The effects of a ten-week physical conditioning program were evaluated in a group of professional hospital personnel. Exercise sessions were held during working hours five times per week and consisted of jogging one mile in a ten-minute period. Results suggested that the program was feasible during the busy workday schedule. Lack of interest, physical impairment, and inadequate facilities, however, contributed to a 42% attrition rate. The data also indicated that definite physiological effects were obtained with these short periods of daily exercise. Mean physical working capacity increased 145 kilopond-meters (kpm)/min; maximal oxygen uptake, 4.16 ml/kg/min; and maximum voluntary ventilation, 28 liters/min. Resting mean heart rate diminished 11 beats per minute. Three risk factors of coronary heart disease, body weight and serum cholesterol and serum triglyceride values, were not altered.