Evaluation of sub-maximal aerobic capacity level determined by double product break point (DPBP) among Japanese adults

Objectives The purpose of this study was to determine sub-maximal aerobic capacity levels evaluated by metabolic equivalents (unit is METs) at the double product break point (DPBP) and elucidate the safe and effective average exercise intensity among Japanese adults. Methods A total of 438 subjects (123 males and 315 females) who participated in the exercise prescription course with measurement of the DPBP during a continuous incremental exercise test with a bicycle ergometer were enrolled in this study. The DP (heart rate-systolic blood pressure product) featured rapid increase with increasing exercise load during the continuous incremental exercise test. Results The metabolic equivalents at the DPBP level for males and females were 5.3±0.9 METs and 4.9±0.7 METs, respectively. Interestingly, the metabolic equivalent at the DPBP level in 87.2% of the study subjects was less than 6 METs. Conclusions This study indicated that some physical activities above moderate intensity, such as the stair climbing (8 METs), might be inappropriate as health promotion exercises. Thus, the upper limit of exercise intensity for health promotion was 6 METs, especially if the subject was at cardiovascular risk. In addition, it was found necessary to make synthetic judgments in consideration of heart rate and rating of perceived exertion (RPE) during exercise.