Anthropometric changes at high altitude.

Eight white males (18-25 yr) were evaluated before, during and after 18-d residence on the summit of Pikes Peak, CO (4300 m; high altitude, HA) to describe the anthropometric changes associated with weight loss and to test the accuracy of a number of previously published prediction equations in assessing any alteration of the relative fat-to-lean tissue ratio during exposure to HA. Body weight (BW), 10 circumference (C), and 7 skinfold (SF) measurements were obtained preprandial at sea level (SL) and on days 2,4,6,9,12,16, and 18 at HA. Body density was estimated by hydrostatic weighing (HW) pre- and post-HA. BW differed from SL (p less than 0.01) after day 9 at HA. HW indicated that the pre- to post-HA weight loss was partitioned into a 2.06 kg loss in fat-free body mass (p less than 0.001) and an insignificant increase in fat wt (0.58 kg). Percent body fat (BF) increased from 16.6 to 17.7 (p less than 0.02). After day 9 of HA, the sum of SF and C measurements increased (p less than 0.02) and decreased (p less than 0.05) from SL, respectively. The largest changes occurred in the chest and scapula SF and in the C of the hip, neck, calf, and two abdominal sites. The alterations in triceps, waist, and total SF were related to the increase in fat weight and BF (r greater than 0.71).(ABSTRACT TRUNCATED AT 250 WORDS)