Effect of Endurance Training on Blood Pressure at Rest, During Exercise and During 24 Hours in Sedentary Men Roger Van Hoof, MD, Peter Hespel, DSc, Robert Fagard, MD, PhD, Paul Lijnen, DSc, Jan Staessen, MD, PhD, and Antoon Amery, MD, PhD The effect of 4 months of physical training on rest- ing, exercise and 24-hour blood pressure (BP) was studied using a randomized crossover design in 26 healthy, sedentary men, with an average age of 39 f 10 (standard deviation) years, Peak oxygen up- take increased by 14% (p <O.OOl) and the physical working capacity at a heart rate of 130 beats/min by 25% (p <O.OOl). The heart rate was reduced by 7 beats/niin at night (p <O.Ol) and by 6 beats/min during the day (p <O.OOl). Trainingiinduced changes of BP varied according to measuring con- ditions. A decrease in BP at rest while sitting in the morning in the laboratory was significant for dia- stolic (-5 mm Hg, p <O.O,l) but not for systolic BP. During exercise, systolic BP was significantly lower after training, when measured at the same sub- maximal workloads. However, when workload was expressed as a percentage of peak oxygen uptake, systolic BP was not different before and after train- ing. When measured during 24 hours, the training- induced change in BP was not significant at night either for systolic or diastolic BP. During the day the decrease in diastolic BP was significant (-5 mm Hg, p <O.OOl), but the change in systolic DP was not. (Am J Cardiol 1989;63:945-949) From the Hypertension and Cardiovascular Rehabilitation Unit, De- partment of Pathophysiology, Catholic University of Leuven, Leuven, and the Epidemiology and Medical Research Unit, Military Hospital of Brussels, Brussels, Belgium. This study was supported in part by the Belgian National Research Foundation (N.F.W.O.-Brussels). Manu- script received October 7, 1988; revised manuscript received and ac- cepted January 30,1989. Address for reprints: Roger van Hoof, MD, Hypertension Unit, Campus Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. S everal long-term epidemiologic follow-up studies have demonstrated that total mortality rates’ and coronary artery mortality* are lower in physically active people than in sedentary ones. The factors most commonly invoked to explain this probable protective effect of physical activity are its beneficial effects on the serum lipid profile3,4 and its hypotensive action.5m7 Cross-sectional physical fitness studies indicate that low physical fitness is associated with a higher prevalence of systemic hypertension,* which has been confirmed in epidemiologic follow-up studies.9 Intervention studies have provided evidence that endurance training can lower blood pressure (BP).5Jo A few studies have dem- onstrated a reduction by physical training of BP during submaximal exercise on a bicycle ergometer.“J* It is, however, not known whether exercise training also low- ers BP measured during normal daily activities or at night. The present study investigated the effect of en- durance training on 24-hour BP in previously sedentary men and assessed the hypotensive effect of training on the BP at rest and during exercise. METHODS Design: Thirty healthy subjects with sedentary jobs were recruited and randomized into 2 equal groups of similar age and weight distribution. All had a BP <160/95 mm Hg, normal electrocardiograms at rest and during a maximal exercise test, and none was tak- ing any medication. They were repeatedly instructed to keep dietary, drinking and smoking habits as constant as possible throughout the study. After baseline labora- tory examinations group 1 was entered into the training program, which consisted of 48 training sessions of 1 hour each at a frequency of 3 sessions every week. Each session was supervised and included, successively, er- gometer-assessed bicycle exercise, rest, jogging, rest and, finally, mainly dynamic calisthenics. Subjects who did not complete the training program within 16 weeks were asked to extend it until completion of the total number (48) of sessions. During the training period of group 1, the subjects in group 2 served as controls. Im- mediately following this first study period, group 2 was entered into the training program whereas the subjects in group 1 served as controls. Measurement procedures: Blood pressure was mea- sured at randomization and at the end of each study period, in a fasting state, 5 times, after the subjects had been sitting for 10 minutes in a comfortable armchair. THE AMERICAN JOURNAL OF CARDIOLOGY APRIL 15, 1989 945