Comparison of physical characteristics, body temperature and resting metabolic rate at 30‡C between subtropical and temperate natives

Anthropometric measurements, measurements of skin temperatures, rectal temperature, heart rate and metabolic rate at 30‡C were made on 25 young male residents of Okinawa who were born and raised in Okinawa (group O) and 25 young male residents of Okinawa who were born and raised on the Japan mainland but moved to Okinawa less than 2 years before the test (group M) in summer. Group O showed significantly shorter height, lighter body weight, and slender body shape than group M. Group O showed thinner skinfold thickness and smaller percentage of body fat content than group M. Skin temperatures for group O were higher than those for group M, and rectal temperature for group O was slightly lower than that for group M. Group O showed, less metabolic rate per body surface area and slower heart rate than group M. It is concluded that physical characteristics of subtropical natives is favorable for heat dissipation, and subtropical natives have superior capacity for non-evaporative heat dissipation than migrants of temperate natives to a subtropical zone.