Load Carrying Walking Test for the Special Operation Forces of the Army of the Czech Republic.

INTRODUCTION: The subject of this study was the creation of a new type of laboratory walking stress test for the Special Forces of the Army of the Czech Republic. This study developed a test model that has been validated in practice and that reflects the fact that the performance of endurance without and with a load varies considerably. Especially, if we focus on operators, as their activities are always performed with loads/full gear (equipment, weapons, equipment, etc.). MATERIALS AND METHODS: 24 men/operators from the Special Forces of the Army of the Czech Republic volunteered for this study. The maximal exercise test/spiroergometry was designed to include performance at a load of 55 kg/121 lb, a constant speed of 5.3 km/h, and an increase in incline angle of 1 degree after each elapsed minute. The test was performed on a treadmill under standard time, location, and temperature conditions. During the test, the following values were recorded: VO2 = oxygen consumption indicating the intensity of the exercise was monitored, VO2/kg = oxygen consumption converted to body weight, VO2/HR = pulse oxygen (the amount of oxygen converted in one heartbeat), HR = heart rate, VE = ventilation, volume of air exhaled in 1 min, breathe frequency (BF) = respiratory rate in 1 min. RESULTS: Out of the total number of 24 respondents, the study found these mean values of variables. The variable mapping the oxygen consumption, which indicates the intensity of VO2 loading, was 3.8, with the lowest value being 3.2 and the highest being 4.5. After converting oxygen consumption to bodyweight, VO2/kg was 46, the lowest value of 38.8, and the highest 53.0 were measured for this variable. Pulse oxygen, i.e., the amount of oxygen calculated per heart contraction VO2/HR, was 20.5, the lowest value 16.0, and the highest 26.0. The average HR heart rate was 183.5, with the lowest value being recorded at 164 and the highest value is 205. Ventilation, i.e., the amount of exhaled air per minute in VE, was measured at 144.9, the lowest value was 114.7, and the highest was 176.6. The BF in 1 min was 58.5, the lowest value 35, and the highest 70. The mean time load was 10:20 min, the shortest test length was 7:25 min, and the longest was 13:23 min. These values correspond to the degree of inclination of the ascent, i.e., the mean value was 10 degrees, the smallest achieved slope was 7 degrees, and the largest 13 degrees. CONCLUSION: The designed weighted walking test proved to be fully functional and effective in measurement. The further established protocol corresponds to the requirements of the current needs of the Special Forces of the Army of the Czech Republic. Last but not least, the walking stress test is applied for the external and internal selection and screening of operators. Data obtained from testing were used to develop deployment requirements for patrol/nuclear combat missions.

Biological factors and self-perception of stress in relation to freeze-like response in humans.

Many animals react to threatening stimuli such as a predator attacks by freezing. However, little experimental research investigated freeze response in humans. Here, we have employed practices commonly used in self-defense training to create two unique scenarios simulating armed physical threat. Sixty healthy men volunteers divided into three groups of twenty (untrained, trained but unexperienced, trained and experienced) underwent these scenarios accompanied by measurement of biochemical, physiological, and psychological markers of stress. Our results show that untrained individuals exhibit stronger freezing reactions, while highly skilled participants display the lowest propensity for freezing, especially in high-intensity scenarios. Moreover, the study shows variations in anxiety levels and selected biomarkers, with cortisol and osteocalcin showing different patterns in low and high-intensity scenarios, and suggests a complex interplay between these factors, electrodermal activity, and stress perception.