title: Assessment of prescribed increases in physical activity: application of a new method for microprocessor analysis of heart rate.
abstract: A portable solid-state recorder-display system was used to measure and analyze heart rate during the waking hours of 3 consecutive days in free-living sedentary normal middle-aged men who were randomized to undergo 3 regimens of physical activity during a 12-week period: low-intensity exercise training at home (n = 21), high-intensity exercise training at home (n = 23) and customary activity (n = 20). This was done to determine whether the system could detect changes in heart rate and, indirectly, in physical activity within the 3 groups. In both training groups the percentage of total recorded time spent within the prescribed high or low heart rate range recorded at 6 or 12 weeks increased significantly (p less than 0.05), whereas control subjects showed no increase above baseline values. Peak oxygen consumption increased by 8% and 17% in men undergoing low- and high-intensity training, whereas in control subjects it did not change. This solid-state system reliably measures prescribed increases in heart rate and provides an indirect measure of physical activity in normal sedentary men undergoing exercise training at home.
mesh_terms: D000553:Ambulatory Care; D003201:Computers; D005069:Evaluation Studies as Topic; D006339:Heart Rate; D006801:Humans; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D010806:Physical Education and Training; D005082:Physical Exertion; D011897:Random Allocation