Heart Rate Variability Recordings are a Valid Non- Invasive Tool for Evaluating Soldiers' Stress
Journal of Defense studies and resource management
The purpose of the present study was to investigate physiological responses and to evaluate heart rate variability as a non-invasive stress indicator during a 72-hour military field training (MFT). Ten healthy male soldiers (age 20 ± 1 yr.) participated in MFT. They slept approximately 2 h/day and ate only army field rations. During MFT, the soldiers' mean (±SD) energy expenditure was 4646 ± 674, energy intake 2200 ± 326, and energy deficit (ED) 2405 ± 890 kcal⋅day -1 . Throughout the entire
... ghout the entire training period, serum total testosterone (TES) reduced from 19.0 ± 3.0 to 12.6 ± 6.2 nmol⋅l -1 (p<0.001). Mean HR during the entire MFT was 85 ± 6 bpm. RMSSD, which reflects cardiac vagal activity, decreased from 54 ± 19 to 42 ± 12 ms (p<0.05). No changes (p>0.05) were observed in HF and LF power, but changes in HF power correlated with baseline serum TES (r=-0.72, p<0.05). Based on the present findings, working for 72 h at a relatively low level of cardiovascular strain with ED and sleep deprivation can individually modify hormonal responses in association with cardiac vagal outflow. This suggests that HRV can be used as a non-invasive tool to measure stress in soldiers during MFT. Citation: Salonen M, Kokko J, Tyyskä J, Koivu M, Kyröläinen H (2013) Heart Rate Variability Recordings are a Valid Non-Invasive Tool for Evaluating Soldiers' Stress. J Def Stud Resour Manage 2:1.