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 trainin g intensity has not been established. This study compared the effects of endurance training at different intensities on ambulatory blood pre ssure 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 mode rate hypertension were evaluated in a crossover fashion according to a Latin square after a sedentary control period and after training at l ow and at moderate intensity corresponding to 50% and 70% of maximal o xygen uptake, respectively. Each period lasted 10 weeks. After trainin g at moderate intensity, a higher maximal oxygen uptake was found comp ared with sedentary values but not after training at low intensity. Bo th training intensities exerted a similar antihypertensive effect of a bout 5 mm Hg for systolic and diastolic 24-hour blood pressures. Howev er, training at low intensity reduced blood pressure exclusively durin g the waking hours, whereas training at a moderate intensity reduced b lood pressure only during the evening and sleeping hours. Waking blood pressure load decreased from 66% to 49% after training at low intensi ty, whereas sleeping blood pressure load decreased from 61% to 34% aft er training at moderate intensity (both P<.05). Conclusions. Low- and moderate-intensity training produce similar 24-hour blood pressure red uctions, but each training intensity may interfere with different path ogenic effects associated with different blood pressure profiles,