Mass-to-surface area index in a large cohort.

Many biological and anthropological investigations have described the role between mass-to-surface area index (M/SA) and heat tolerance. No large M/SA database exists that can be used as a reference standard to interpret previous or future M/SA studies. This report presents the M/SA data of a large military cohort (1,170 males aged 17-54 years, 305 females aged 17-40 years). The effects of gender, ethnic group, and age on the distribution of M/SA, as well as the relationship between M/SA and other physical characteristics, were described. It was observed that the increases of M/SA with increasing age (over the 17-75 years category) were not significant. All descriptive characteristics (including M/SA) were different (P less than .001) between males and females. M/SA was not statistically different between ethnic groups among both males and females. These data may be utilized to compare the M/SA values of U.S. citizens to those of other ethnic groups and to identify those laborers or athletes who possess the greatest theoretical risk of heat intolerance.