Quantity of Physical Exercise Expended during Commuting by Office Workers Residing in the Greater Tokyo Area

Objectives: We measured how much physical exercise of moderate-to-high intensity was performed daily during commuting times by office workers who reside in the Greater Tokyo Area and use a train for commuting. Methods: The physical activity was measured by a portable accelerometer, Omron HJA-350 IT, which records METs (Metabolic Equivalents) every minute. The data were downloaded to a personal computer for calculation of the exercise quantity in specified time intervals. Exercise (Ex) was defined as (METs≥3) × hours. Results: Male commuters using the train (n=74) were found to spend 70 ± 30 and 103 ± 47 minutes for morning and evening commuting, respectively. They expended 3.4 ± 1.7 Ex in the commuting of both morning and evening. This exercise quantity amounts to 64% of the whole day Ex, which was 2.9 times the whole day Ex of car commuters (n=78). The daily walking activity of the train commuters, 9,305 ± 2,651 steps, was 2.7 times that of the car commuters (3,490 ± 1,406 steps). The mean total Ex expended by the train commuters over 5 weekdays was calculated to be 26.5 Ex, which exceeds the weekly 23 Ex recommended by Guideline on Physical Exercise for Good Health, 2006, Japanese Ministry of Health, Labour, and Welfare. Conclusions: Train commuting by office workers residing in the Greater Tokyo Area seems to contribute to their physical health. (San Ei Shi 2010; 52: 133-139)