Evaluation of stress induced by flight activity by measuring the hormonal response

The aim of the present study was to quantitatively investigate the different levels of adaptation to flight and to evaluate the hormonal response to flight activity as a possible reliable tool to quantify the level of stress induced by flight. The hormonal response of growth hormone (GH), cortisol, and prolactin (PRL) to flight activity was evaluated in a group of student pilots (n = 11; all male; age 20 +/- 2 years) and flight instructors (n = 11; all male; age 27 +/- 2 years) of an Italian Air Force flight school. Blood samples were obtained immediately before and after a training flight session. Hormonal determination by RIA technique after flight showed a significant increase of plasma hormonal levels of GH, PRL, and cortisol in the students. Conversely, in the instructors only GH showed a significant increase versus preflight values, whereas PRL and cortisol did not show significant differences. Moreover, preflight hormonal levels of GH and PRL were significantly higher for student pilots compared to the same values for flight instructors. The data lead to establishing a close correlation between the hormonal response to flight activity and the level of tolerance and adaptation to flight-induced stress.