EFFECTS OF DIFFERENT TRAINING INTENSITIES ON 24-HOUR BLOOD-PRESSURE IN HYPERTENSIVE SUBJECTS

Background. It is generally accepted that physical training decreases blood pressure in hypertensive subjects, but the importance of training intensity has not been established. This study compared the effects of endurance training at different intensities on ambulatory blood pressure and on blood pressure load (percentage of readings above 140/90 and 120/80 mm Hg during the waking and sleeping periods, respectively). Methods and Results. Previously sedentary subjects with mild to moderate hypertension were evaluated in a crossover fashion according to a Latin square after a sedentary control period and after training at low and at moderate intensity corresponding to 50% and 70% of maximal oxygen uptake, respectively. Each period lasted 10 weeks. After training at moderate intensity, a higher maximal oxygen uptake was found compared with sedentary values but not after training at low intensity. Both training intensities exerted a similar antihypertensive effect of about 5 mm Hg for systolic and diastolic 24-hour blood pressures. However, training at low intensity reduced blood pressure exclusively during the waking hours, whereas training at a moderate intensity reduced blood pressure only during the evening and sleeping hours. Waking blood pressure load decreased from 66% to 49% after training at low intensity, whereas sleeping blood pressure load decreased from 61% to 34% after training at moderate intensity (both P<.05). Conclusions. Low- and moderate-intensity training produce similar 24-hour blood pressure reductions, but each training intensity may interfere with different pathogenic effects associated with different blood pressure profiles,