The effects of strength training and centrifuge exposure on +Gz tolerance.

Weight training (WT) as a countermeasure to +Gz intolerance seems to be an accepted modality, but lacks convincing support in the research literature. This study examines factors associated with WT in an operational environment as a countermeasure to +Gz intolerance. Fourteen naval aviators were assigned to a WT group (n = 7) and a non-weight-trained control (NWT) group (n = 7). All subjects were tested before and after a 10-week training period for aerobic capacity (VO2max), dynamic muscular strength (Cybex II), body fat, gradual onset rate (GOR) for +Gz at a rate of +1 G.15 s-1, and finally a simulated air combat maneuver (SACM) consisting of 15 s at +4.5 Gz and +7 Gz alternating challenges to exhaustion. The results indicate the following: 1) no significant differences in any of the centrifuge variables measured between WT and NWT groups while both groups showed a time or learning effect in SACM from 175 +/- 109 to 239 +/- 110 s (grouped data df = 16, t = 2.97, p < 0.09); 2) no improvement in SACM time for subjects achieving a 300-s SACM pretest value (n = 4); and 3) for SACM times below 300 s, the WT subjects showed a greater improvement than NWT subjects (n = 11, F = 9.12, p < 0.02). The data suggest that although some subjects showed considerable strength gains, WT in a naval aviation operational setting may not provide a universal desired effect.(ABSTRACT TRUNCATED AT 250 WORDS)