Effect of Experience and Psychophysiological Modification by Combat Stress in Soldier's Memory.

The present research aimed to analyze the effect of experience and psychophysiological modification by combat stress in soldier's memory in a simulated combat situation. Variables of rate of perceived exertion, blood glucose, blood lactate, lower body muscular strength manifestation, cortical arousal, specific fine motor skills, autonomic modulation, state anxiety, and memory and attention through a postmission questionnaire were analyzed before and after a combat simulation in 15 experienced soldiers of a special operation unit and 20 non-experienced soldiers of light infantry unit from the Spanish Army. The stress of combat simulation produces a significant increase (p < 0.05) in rated perceived exertion, blood glucose, blood lactate, somatic anxiety and a low frequency domain of the heart rate, and a significant decrease of rifle magazine reload time, high frequency domain of the heart rate and somatic anxiety in both groups. The variables of RPE, glucose, CFFT, RMRT, RMSSD, LF/HF, CA, SA and STAI were significantly different in experienced soldiers shown the activation of fight-flight system. The anticipatory anxiety in experienced soldiers shows a cognitive behavioral association by past experiences. The analysis of correct response in the postmission questionnaire show elements more related with the sight and that endanger the physical integrity of soldiers are more remembered, and some significant differences (p < 0.05) in the memory performance of experienced soldiers and non experienced soldiers where experienced soldiers shown a better performance. As conclusion, combat stress produce an increase in the psichophysiological response of soldiers independently of experience, but experienced ones presented a lower negative effect on memory than non experienced.

Amateur endurance triathletes' performance is improved independently of volume or intensity based training.

The aim of the present research was to compare the effects in swimming and running performance, horizontal jump test, autonomic modulation, and body composition of four training weeks with emphasis on volume versus intensity in moderate trained triathletes. Thirty-two amateur triathletes (20 males and 12 females) were randomly divided in three different groups that performed 6 training session per week: Intensity (INT): training focused on performs intensity training Volume (VOL): training focused on performs volume training; and Control (CON): physical active group with no periodized training. Body composition, heart rate variability, horizontal jump test, swimming and 2000 m running test were tested before and after the training period. There were no significant differences between INT and VOL in running test. Furthermore, both INT and VOL training groups improved 50 m (p: 0.046 and 0.042 respectively) and 400 m (p: 0.044 and 0.041 respectively) swimming performance. Moreover, there were no significant differences among groups in any moment in HRV variables. No significant difference was observed for horizontal jump test and body composition between the INT and VOL group at any time. According to the results of the present study, four weeks of training with either high intensity or volume results to similar adaptations in endurance, horizontal jump test and body composition parameters in amateur triathletes.

Inalambric Biofeedback Devices to Analyze Strength Manifestation in Military Population.

The study of the effect of stress on both combatants physiological and anatomical systems have been poor studied in the specific literature. The present research aimed to study the effect of combat stress in strength manifestations of leg flexor-extensor muscles and the anaerobic metabolism of soldiers. Before and after asymmetrical combat simulation were analyzed parameters of blood lactate concentration, explosive leg strength manifestation and contractile capacity of leg muscle in 186 professional soldiers. Results showed a significant increase (p < 0.05) in blood lactate values (2.23 ± 0.95 vs 7.47 ± 3.67 mmol/L), explosive leg strength (Squat Jump 0.31 ± 0.06 vs 0.35 ± 0.07 m, Countermovement Jump 0.33 ± 0.07 vs 0.36 ± 0.07 m, Abalakov Jump 0.39 ± 0.08 vs 0.41 ± 0.09 m), and a significant decrease of the elastic capacity (0.022 ± 0.04 vs 0.021 ± 0.04) and recruitment and muscle synchronization capability (0.028 ± 0.04 vs 0.026 ± 0.04). This data suggest that combat stress increases the leg strength manifestation despite the significantly increase of muscle acidosis after a combat simulation. This result is probably due to the high activation of the fight-flight system of soldiers which increases the organic response of soldiers and that can compensate the prejudicial effect of acidosis in muscle contraction. These results could be used by officers to improve specific training programs and to improve planning and election of equipment and material for the development of different missions in current theaters of operations.

Combat Stress Decreases Memory of Warfighters in Action.

The present research aimed to analyze the effect of combat stress in the psychophysiological response and attention and memory of warfighters in a simulated combat situation. Variables of blood oxygen saturation, heart rate, blood glucose, blood lactate, body temperature, lower body muscular strength manifestation, cortical arousal, autonomic modulation, state anxiety and memory and attention through a postmission questionnaire were analyzed before and after a combat simulation in 20 male professional Spanish Army warfighters. The combat simulation produces a significant increase (p < 0.05) in explosive leg strength, rated perceived exertion, blood glucose, blood lactate, somatic anxiety, heart rate, and low frequency domain of the HRV (LF) and a significant decrease of high frequency domain of the heart rate variability (HF). The percentage of correct response in the postmission questionnaire parameters show that elements more related with a physical integrity threat are the most correctly remembered. There were significant differences in the postmission questionnaire variables when participants were divided by the cortical arousal post: sounds no response, mobile phone correct, mobile phone no response, odours correct. The correlation analysis showed positive correlations: LF post/body temperature post, HF post/correct sound, body temperature post/glucose post, CFFTpre/lactate post, CFFT post/wrong sound, glucose post/AC pre, AC post/wrong fusil, AS post/SC post and SC post/wrong olfactory; and negative correlations: LF post/correct sound, body temperature post/lactate post and glucose post/lactate post. This data suggest that combat stress actives fight-flight system of soldiers. As conclusion, Combat stress produces an increased psychophysiological response that cause a selective decrease of memory, depending on the nature, dangerous or harmless of the objects.