Correlation of age, height, and gender with +Gz tolerance among healthy Indian participants

Introduction: Aircrew are repetitively exposed to positive Gz acceleration in fighter flying. Factors affecting +Gz tolerance vary among individuals and are determined by both modifiable and non-modifiable factors. Some of the non-modifiable factors influencing +Gz tolerance are age, gender, and height. The present study was undertaken to understand the relationship of these variables with relaxed +Gz tolerance. Material and Methods: The study involved a retrospective analysis of existing database of the high-performance human centrifuge at the Institute of Aerospace Medicine. Relevant data from 70 non-aircrew subjects were included for the study. Of these, 39 were male and 31 were female. The age and height varied from 27 to 38 years and 157 to 187 cm, respectively. The data were analyzed using Microsoft Office Excel® to find the correlation between age and height with relaxed +Gz tolerance. Relaxed +Gz tolerance of men and women was compared using unpaired t-test. Significance was set at P < 0.05. Results: The mean age, height, and relaxed +Gz tolerance of males were found to be 30.25 ± 4.3 years, 172.58 ± 6.5 cm, and 4.89 ± 0.67G, respectively, whereas those of females were 27.28 ± 3.36 years, 158.46 ± 6.78 cm, and 4.4 ± 0.85G, respectively. In both males and females, age and height showed no correlation with relaxed +Gz tolerance. However, the relaxed +Gz tolerance was found to be higher in males and this difference was statistically different (P = 0.008). Conclusion: Age and height showed no correlation with relaxed +Gz tolerance in both males and females nonaircrew subjects. Males exhibited a statistically significant, higher relaxed +Gz tolerance as compared to females.