Biochemical and Hormone Markers in Firefighters: Effects of "Search, Rescue, and Survival Training" and Its Recovery

• Published in: Journal of strength and conditioning research 2024-04, Vol.38 (4), p.e189-e201
• Main Authors: Ponce, Thalita, Mainenti, Míriam Raquel Meira, Barros, Thiago, Cahuê, Fabio Luiz Cândido, Fernanda Martins Dos Santos, Camilli, Piazera, Bruna Karoline Lima, Salerno, Verônica P, Vaisman, Mario
• Format: Article
• Language: English
• Subjects: Alanine transaminase; Aspartate aminotransferase; Body composition; Body fat; Cognitive ability; Cortisol; Creatine; Creatine kinase; Dietary restrictions; Firefighters; Glutathione Disulfide; Glutathione peroxidase; Growth Hormone; Growth hormones; Hormones; Human Growth Hormone; Humans; Hydrocortisone; Insulin-Like Growth Factor I; Insulin-like growth factors; L-Lactate dehydrogenase; Male; Sleep deprivation; Survival; Testosterone; γ-Glutamyltransferase
• ISSN: 1064-8011; 1533-4287
• DOI: 10.1519/JSC.0000000000004695

Ponce, T, Mainenti, MRM, de Barros, T, Cahuê, FLC, Fernanda, C, Piazera, BKL, Salerno, VP, and Vaisman, M. Biochemical and hormone markers in firefighters: effects of "search, rescue, and survival training" and its recovery. J Strength Cond Res 38(4): e189-e201, 2024-This study aimed to evaluate the hormonal and biochemical responses in military firefighter cadets to a search, rescue, and survival training (SRST) course. Forty-three male volunteers participated in the SRST over 15 days consisting of intense physical effort, sleep deprivation, and a survival period with food deprivation. At 3 timepoints (baseline, SRST, and 1 week rec), subjects submitted to blood collections, body composition examinations, physical performance evaluations, and cognitive function tests. After the SRST, lower values were registered for testosterone (764.0; 565.1-895.0 to 180.6; 133.6-253.5 ng·dl -1 ) and insulin-like growth factor-1 (IGF-1) (217; 180-238 to 116; 102-143 ng·ml -1 ). Increases were observed for cortisol (9.7; 8.2-11.7 to 18.3; 16.5-21,2 μg·dl -1 ), growth hormone (GH) (0.11; 0.06-0.20 to 2.17; 1.4-3.4 ng·ml -1 ), CP, GSSG, lactate dehydrogenase, alanine aminotransferase, and aspartate aminotransferase as well as the antioxidant response of superoxide dismutase and glutathione peroxidase. The values of gamma-glutamyl transferase were reduced. After 1 week of recovery, levels of GH, creatine kinase, GSH, and GSSG returned to baseline values ( p < 0.05). Vertical jump performance presented a regular positive correlation with testosterone (rho = 0.56 and p < 0.0001) and a strong negative correlation with cortisol (rho = -0.61 and p < 0.0001). Body fat showed a regular and positive correlation with both testosterone and IGF-1. We conclude that participation in the SRST caused significant hormonal and biochemical changes in individuals that correlated with a loss in physical performance. Importantly, the results suggest the need for longer recovery times before a return to normal military duties.