Evaluation of occupational physical load during 6-month international crisis management operation

Abstract

Objectives: Generally, operational military duties are associated with a variety of stressors, such as prolonged physical activity (PA). However, limited information is available on the occupational workload or changes in PA during international military operations. Thus, the aim of the study was to investigate the changes in body composition, stress biomarkers, PA, and heart rate (HR) responses of 79 male soldiers during a 6-month international crisis management operation. Material and Methods: Measurements were conducted 3 times in South-Lebanon during the operation. Body composition was assessed by the bioelectrical impedance method. Blood samples were analyzed for serum testosterone, sex-hormone binding globulin (SHBG), cortisol and insulin-like growth factor. Saliva sampling was used for analyzing stress biomarkers, cortisol and α-amylase. Heart rate and physical activity were monitored by a recordable belt and tri-axial accelerometer, respectively. Results: Increases in muscle mass (39.2±4.1 vs. 39.5±4.2 kg, p < 0.05) and testosterone (15.9±4.6 vs. 17.2±4 nmol/l, p < 0.01), and reductions in PA variables (e.g., daily step count 9472±2547 vs. 8321±2720, p < 0.05) were observed during the first half (i.e., PRE-MID) of the study. The increase in muscle mass remained significant during the latter half (PRE-POST, 39.2±4.1 vs. 39.6±4.4 kg, p < 0.05), but also fat mass increased (MID-POST, 10.6±4.6 vs. 11.0±4.7 kg, p < 0.05) while SHBG (MID-POST, 31.8±12.1 vs. 26.6±13.2 nmol/l, p < 0.01) and cortisol (MID-POST, 445±116 vs. 400±123 nmol/l, p < 0.05) decreased. With the exception of increased concentration of salivary α-amylase (PRE-POST, 36.5±33.7 vs. 55.1±39.7 U/ml), the acute stress biomarkers and HR responses remained unchanged. Furthermore, the low quantity of PA, low HR values and subjective ratings of exertion refer to rather light physical workload. Conclusions: Due to the operatively calm nature of the working environment, the present soldiers did not express any significant signs of physical overload during the study period. Int J Occup Med Environ Health 2018;31(2): 185 -197

Differences in Training Adaptations of Endurance Performance during Combined Strength and Endurance Training in a 6-Month Crisis Management Operation

“…Furthermore, the present body composition and blood biomarker results did not reflect disturbances in hormonal balance either in the HiR or LoR group. These findings are supported by previously published results of rather low physical activity and work load [26], as well as well-maintained energy balance [27] during the same crisis management operation. Thus, there were no environmental or physiological barriers for the training adaptations during the operation.…”

“…During the study, the soldiers performed their operative duties including typical military tasks, such as patrolling and observing outside the military base, as well as maintenance and headquarter duties inside the base. Recently, a more detailed description of the physical activity and work load [26] of the participants as well as their diet [27] has been published. Sixty-six voluntary male soldiers who were deployed for a crisis management operation in the Middle East took part in the baseline measurements.…”

Diet Macronutrient Composition, Physical Activity, and Body Composition in Soldiers During 6 Months Deployment

“…Despite the training facilities inside the camp, the soldiers could not sustain their levels of physical activity during this deployment. Heart rate responses and stable hormonal levels support the assumption that the soldiers did not experience overload symptoms (11). Due to the nature of accelerometer movement detection, some stationary physical activity such as weight lifting was not necessarily recorded by the accelerometers Strengths and limitations of the study A unique set of data regarding food intake straight from the deployment area was obtained under a controlled situation due to a research group in the vicinity which enabled the accurate observation of food servings during the measurements.…”

“…Step count did not meet the minimum daily health recommendation (10 000 steps) (20). One reason for the observed level of physical activity is low work load and calm security situation in the operational area (11). Secondly, the camp area was not wide that the soldiers took only few steps for their daily routines.…”

Effects of training and a semester break on physical fitness of police trainees

“…Trainees were then instructed to bend the elbows and lower their chest toward the ground while maintaining the body posture previously described. A repetition was counted when the elbow joint crossed the position of 90 ° and then returned to the starting position (Pihlainen, Santtila, Vasankari, Häkkinen, & Kyröläinen, 2018). Trainees were allowed to rest during the test by raising one hand from the floor to unload and relax the hand.…”