Women's G tolerance.
G tolerances of 102 women and 139 men subjected to Standard Medical Evaluation (Medeval) G Profiles were compared. Unpaired t-tests revealed no significant difference between the women and men in either relaxed or straining G tolerance. Covariance analysis controlling for differences in tolerance due to age, height, weight, and activity status revealed the women to have marginally lower tolerance; the analysis also identified height as a factor having a strong negative influence on G tolerance, and weight as having a positive influence. When the women were matched only by height to the men in the comparison group, the women's mean G tolerances were significantly lower than the men's. On Standard Training G Profiles 88% of 24 women and 80% of 213 men completed the runs, but this difference was not significant. G tolerances of 47 women were measured on the Medeval Profiles both during and between menses, but no significant differences related to menstruation were found. No important differences between women and men in signs or symptoms of G stress were observed, except for two instances of urinary stress incontinence in women during the Training Profiles. We conclude that women should not categorically be excluded from aircrew duties for reasons of G intolerance.