Mass-To-Surface Area Ratio in Military Personnel

• Main Authors: DeLuca, J P, Armstrong, L E, Christensen, E L, Hubbard, R W, Vogel, J A
• Format: Report
• Language: English
• Subjects: ACCURACY; ADDITION; ADIPOSE TISSUE; ANTHROPOMETRY; ARMY PERSONNEL; AS879; BLACKS(RACIAL GROUP); BODY WEIGHT; COMPUTATIONS; ETHNIC GROUPS; FEMALES; HEAT; HEAT LOSS; HEAT TOLERANCE; HEIGHT; HIGH HUMIDITY; HOT REGIONS; INDEXES; MASS TO SURFACE AREA RATIOS; PE62787A; RATIOS; REDUCTION; SKIN(ANATOMY); SPECIFIC HEAT; STORAGE; Stress Physiology; SURFACES; WU129

Mass to surface area ratio (M/SA) was calculated from the body weight and skin surface area of 1513 male and female U.S. Army personnel. It has been suggested that M/SA plays a role in thermoregulation, particularly in hot humid environments, since both body weight and surface area affect the rate of body heat storage. The purpose of this investigation was to provide a data base to be used when interpreting M/SA data in the future. The effects of gender, ethnic group, and age on the distribution of M/SA were examined, in addition to the relationship between M/SA and other physical characteristics. This report also describes the physical characteristics of individuals at the extremes of the M/ SA distribution, who may have reduced heat dissipation capacity under certain conditions of heat and humidity. Important findings may be summarized as follows: (1) M/SA increased significantly in both males and females after age 24, and after age 29 in males (p.025). Therefore, M/SA should be compared with data in the appropriate age group. The increase in M/SA with age may be explained by an increase in percent body fat (%BF). %BF increased significantly in both males and females after age 24 (p.025). (2) M/SA was statistically similar between ethnic groups in both males and females. However, black males had a lower %BF and a larger fat-free mass than males in other ethnic groups (p.001). (3) For the first time, four equations are presented which allow an accurate calculation of M/SA (r2=.99) using only height and weight. The results of this investigation will be useful in analyzing data in future studies designed to determine if M/SA is in fact an index of heat tolerance.