A correction has been applied to this article in:
Corrigendum: Psychophysiological Patterns Related to Success in a Special Operation Selection Course
Alberto J. Hormeño-Holgado
Pantelis T. Nikolaidis
Vicente J. Clemente-Suárez- 1Faculty of Sports Sciences, Universidad Europea de Madrid, Villaviciosa de Odón, Spain
- 2Studies Centre in Applied Combat (CESCA), Toledo, Spain
- 3Exercise Physiology Laboratory, Nikaia, Greece
- 4Grupo de Investigación en Cultura, Educación y Sociedad, Universidad de la Costa, Barranquilla, Colombia
Actual theaters of operations require fast actions from special operations units with a high level of readiness and survival. Mission accomplishment depends on their psychological and physiological performance. The aim of the present study was to analyze: (1) the physical parameters related with success in a special operation selection course; and (2) the modifications of the psychological profile of recruits before and after a special operation selection course. Fifty-five male soldiers of the Spanish Army (25.1 ± 5.0 years, 1.8 ± 0.1 cm, 76.8 ± 7.9 kg, 24.4 ± 2.5 kg/m2) undertaking a 10-week special operation selection course performed a battery of physiological and psychological tests. Results showed how successful soldiers presented higher leg strength, anaerobic running performance, and cardiovascular response than non-successful soldiers. The psychological values of life engagement test, acceptance and action questionnaire, coping flexibility scale, and perceived stress scale did not present significant differences after the selection course. We can conclude that success in a special operation selection course was related to higher anaerobic and cardiovascular fitness. This special operation selection course did not modify the psychological profile of successful soldiers.
Introduction
Actual armed conflicts have changed from traditional symmetrical confrontations to an asymmetrical battlefield, characterized by an unstructured and undefined battlefield, where the presence of civilians is becoming more prevalent (Tornero-Aguilera et al., 2017). Those actual theaters of operations require actions to be carried out promptly and briefly with a high level of readiness and survival, sometimes carrying a heavy load, fast movements, tactical parachute jumps or obstacles crossing, being special operations units basic for these new war operations (Tornero-Aguilera et al., 2018). Special operations units are those taking charge of these missions, where their survivability and mission accomplishment depend on their psychological and physiological performance (Tornero-Aguilera and Clemente-Suárez, 2018; Hormeño-Holgado et al., 2019). These situations under extreme conditions have been previously studied in high-demands context as ultraendurance events (Belinchon-deMiguel and Clemente-Suárez, 2018), parachuting (Clemente-Suárez et al., 2017a,b,c), different military combat situations like melee combat (Clemente-Suarez et al., 2018), airmobile protection teams actions (Hormeño-Holgado and Clemente-Suárez, 2019a,b) and in military aircraft pilots (Bustamante-Sánchez et al., 2018, 2019; Hormeño-Holgado and Clemente-Suárez, 2019a,b). During these situations, an increase in sympathetic nervous system, lactic anaerobic metabolism, muscular and cardiovascular response and a decrease in cortical arousal, time perception, rate of perceived exertion and memory were observed (Clemente-Suarez et al., 2018; Delgado-Moreno et al., 2018; Tornero-Aguilera et al., 2018). The constant exposition to these extreme conditions might also lead warfighters to psychologically related disorders, such as anxiety, depression, or post-traumatic stress disorder (Grossman and Siddle, 2008; Hines et al., 2014; Xue et al., 2015). Recent literature supports that previous experience and training influence the psychophysiological responses to these contexts (Tornero-Aguilera and Clemente-Suárez, 2018) and propose specific training models for this context and population as a useful tool to improve the warfighters’ psychophysiological response and operability (Diaz-Manzano et al., 2018a; Curiel-Regueros et al., 2019; Tornero-Aguilera and Clemente-Suárez, 2019).
The psychophysiological profile of a special operations unit must be specific and flexible to prepare their members to deal with any threat that may appear during combat. Previously, physical training has been recognized as essential for readiness (Curiel-Regueros et al., 2019; Tornero-Aguilera and Clemente-Suárez, 2019), whereas an optimal psychological structure is critical to empowering the warfighter with a better response in high-stress conditions (Bellido et al., 2018). Despite its importance, the physiological training patterns of special operations soldiers, as well as the modifications in their psychological profile, have not been determined. Therefore, the aim of the present study was to analyze: (1) the physical parameters related with success in a special operation selection course and (2) the modifications of the psychological profile of recruits during a special operation selection course. The research hypotheses were: (1) aerobic fitness would be related to success in a special operation selection course and (2) a special operation selection course would increase resilience and decrease perceived stress of recruits.
Methods and Materials
Participants
Fifty-five male soldiers of the Spanish Army (25.1 ± 5.0 years, 1.8 ± 0.1 cm, 76.8 ± 7.9 kg, 24.4 ± 2.5 kg/m2) undertaking a 10-week special operation selection course participated in this study. All participants had 29.1 ± 59.3 months of professional experience at the armed forces, 4.3 ± 7.7 months at the unit, and 0.5 ± 2.5 months of experience of real-life combat in Lebanon, Afghanistan, Bosnia, Kosovo, or Iraq. Prior to participation, the experimental procedures were explained to participants, who provided their voluntary written informed consent in accordance with the Declaration of Helsinki. The headquarters of the unit and the military ethics committee approved the study protocols and procedures.
Procedure
Before the 10-week special operation selection course, physical tests were performed in order to complete the specific objective (1) before, during, and after the 10-week special operation selection course, psychological tests were administrated to the participants in order to complete the specific objective (2).
In the special operation selection course, participants had to deal with endurance walks, decision-making scenarios under pressure, obstacle courses, group heavy lifting, ground and water survival, maneuvers under fire or room breaching and clearing among others.
Physical Tests
The following physical tests were conducted:
1. In lower body muscular strength by means of horizontal jump test, subjects performed a standardized warm-up consisting of 2x10 vertical jumps with 30 seconds of recovery and then, they performed two maximal horizontal jumps as mentioned in a previous report (Clemente-Suárez et al., 2018) and the best attempt was used for the statistical analysis.
2. Anaerobic performance was measured by the time of completion of a 50-m maximal running test.
3. Aerobic performance was measured by a 2000-m maximal running test, which is associated with the maximal aerobic speed measured in an incremental test conducted in laboratory (Coutts et al., 2007). Heart rate (HR) was evaluated by a polar s600 (Polar electro. Finland).
4. Rating of perceived exertion (RPE) by the Borg 6–20 scale was evaluated in both running tests.
Psychological Tests
The following psychological tests were administered:
1. The life engagement test (LET) was designed to measure purpose in life, defined in terms of the extent to which a person engages in activities that are personally valued (Scheier et al., 2006).
2. Acceptance and action questionnaire (AAQ-II): measured psychological inflexibility considering it as a transdiagnostic process across psychological disorders (Wolgast, 2014).
3. The coping flexibility scale (CFS): this scale was designed to measure the flexibility in coping with different situations. It refers to the presence of adaptive coping strategies that are associated with better psychological health. This test has 10 items and is answered on a Likert scale ranging from 1 to 4, with 1 = very applicable and 4 = not applicable. Item example: “I am aware of the success or failure of my attempts to deal with stress” (Kato, 2012).
4. Perceived stress scale (PSS): this scale assesses the level of perceived stress in a 1-month period. It is composed of 14 items that are answered in a 5-point Likert scale, where 0 = never and 4 = very often. An example item is “In the last month, how often have you felt that had everything under control?” High scores are related to a higher perception of stress (Cohen et al., 1983).
Statistical Analysis
To analyze the data, we used the SPSS statistical package (version 22.0; SPSS, Inc., Chicago, III.). Means and standard deviation (SD) were calculated using traditional statistical techniques. Normality and homoscedasticity assumptions were checked with a Kolmogorov–Smirnov test. To analyze differences between pre, during and post special operation selection course samples, a One-way ANOVA for dependent samples was administer, and to analyze differences between successful and non-successful soldiers in the special operation selection course a t-test for independent samples was used. The effect size (ES) was tested by Cohen’s d [ES = (post-test mean − pre-test mean)/pre-test SD]. The level of significance for all the comparisons was set at p < 0.05.
Results
Results are reported as mean ± SD. Physical variables of successful and non-successful soldiers in the special operation selection course showed that horizontal jump, 50-m performance, and HR in the 2000-m tests where significantly (p < 0.05) higher in successful than in non-successful soldiers. The values of weight, RPE in 50 m test, 2000 m test and RPE in 2000 n test between successful and non-successful soldiers did not present significant differences (Table 1).
TABLE 1
Table 1. Physical variables of successful and non-successful soldiers in the special operation selection course.
The values of the psychological variables measured before, during, and after the special operation selection course (LET, AAQ-II, CFS, and PSS) did not present significant modifications (p > 0.05) during the entire selection course (Table 2).
TABLE 2
Table 2. Psychological variables before, during, and after the special operation selection course.
Discussion
The aim of this study was to analyze: (1) the physical parameters related to success in a special operation selection course and (2) the modifications of the psychological profile of recruits before and after a special operation selection course. The first hypothesis was not compiled since anaerobic fitness was related with success in the special operation selection course, and the second hypothesis was also not complied since no modifications in psychological profile were found.
Successful soldiers in the special operations selection course presented significantly higher leg strength, anaerobic running performance, and cardiovascular response in the aerobic running test than non-successful soldiers. These results highlighted the importance of anaerobic metabolic pathways in line with present researches focused on the psychophysiological response in different combat contexts. In these studies, authors found a large anaerobic metabolism activation measured by the blood lactate concentration in military parachute jumps, close quarter combat, urban combat, and airmobile protection teams (Clemente-Suarez and Robles-Perez, 2013; Delgado-Moreno et al., 2017; Sánchez-Molina et al., 2017; Clemente-Suárez et al., 2017a,b,c; Diaz-Manzano et al., 2018a,b; Hormeño-Holgado et al., 2019). In this line, the higher 2000-m HR of successful soldiers in the present research also showed how the possibility to reach a higher physical effort was an important factor for these special operations units. Previous authors found how elite soldiers differ from non-elite soldiers by the higher cardiovascular and metabolic output in combat simulations (Tornero-Aguilera et al., 2017). The capacity to reach this large organic response led them to comply with their tactical objective, increasing their operability. This fact could explain the differences in HR by the successful and non-successful soldiers of the present research, as well as previous authors found how combat actions are conducted with intensities over the anaerobic threshold, fact that also highlighted the importance of been able to manifest a high cardiovascular response (Clemente-Suárez et al., 2016; Sánchez-Molina et al., 2017; Bustamante-Sánchez et al., 2018, 2019; Hormeño-Holgado et al., 2019). Nerveless, no significant differences were found in the aerobic test performance (2000 m). This is probably because traditional military training is mainly focused on long-running as a core training and assessment method (Poston et al., 2017). Although distance running can improve aerobic endurance, the requirements of actual operations are more related with anaerobic metabolic pathways as current researches showed (Scherr et al., 2013; Poston et al., 2017; Keramidas et al., 2018; Curiel-Regueros et al., 2019; Tornero-Aguilera and Clemente-Suárez, 2019).
Regarding the psychological response, the increase in stress elicits the hyperactivity of the sympathetic nervous system and a transient emotional state characterized by feelings of tension and apprehension observed in other military environments (Delgado-Moreno et al., 2017; Clemente-Suarez et al., 2018; Sánchez-Molina et al., 2018). Maladaptive psychophysiological stress response in combat could negatively affect otherwise soldiers outcomes, supposing a risk for them (Andersen and Gustafsberg, 2016) and supporting the importance of psychological preparation in these units (Clemente-Suarez and Robles-Perez, 2013; Hormeño-Holgado et al., 2019). Psychological tests’ measurements before, during, and after the special operations selection course did not show a significant modification. The psychological screening process before starting the special operations unit could be a determining factor for maintaining the psychological structure required for these high-demand units. This result was in line with previous researches in special operations units where the soldiers’ psychological profile was a variable large stable and with low modification by operative stressors (Tornero-Aguilera et al., 2017). As observed in undergraduate psychology students, coping flexibility and optimism have been previously strongly correlated and considered individually strong predictors of perceived stress and life satisfaction (Reed, 2016). Developing optimism could increase a person’s ability to cope with stress. In a health employee sample, a goodness-of-fit approach to coping flexibility has already been successfully implemented (Iwata and Buka, 2002). Positive coping strategies are found to lead to greater resilience and physical well-being important for military personnel (Chen et al., 2018). Previous researches showed how in special operations units, the psychological profile was a variable large stable and with low modification by operative stressors (Tornero-Aguilera et al., 2017). This could also be based on the soldier’s experience in this kind of environment and the previous screening for these units.
Practical Application
Analyzing the operative physical demands of soldiers, it was observed that both anaerobic and aerobic metabolism were key factors in missions’ success and operability (Tornero-Aguilera et al., 2017). Both targets could be achieved through HIIT methodology (Diaz-Manzano et al., 2018b; Curiel-Regueros et al., 2019; Tornero-Aguilera and Clemente-Suárez, 2019), showing greater physical outcomes (Clemente-Suárez, 2018), injury prevention (Knapik et al., 2004), and health development (Serrano et al., 2001) than conventional approaches.
Conclusion
Success in a special operation selection course was related to higher anaerobic performance and cardiovascular fitness. This special operation selection course did not modify the psychological profile of successful soldiers.
Data Availability
All datasets generated for this study are included in the manuscript and/or the supplementary files.
Ethics Statement
Universidad Europea de Madrid Ethic Committee, project number: CIPI/18/093.
Author Contributions
AH-H, PN, and VC-S conceived and conducted the experiment and analyzed the results. All authors wrote and reviewed the manuscript.
Funding
This article was fully funded by Universidad Europea de Madrid.
Conflict of Interest Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The reviewer KMH-M declared a past co-authorship with one of the authors VC-S to the handling editor.
References
Andersen, J. P., and Gustafsberg, H. (2016). A training method to improve police use of force decision making. SAGE Open 6:215824401663870. doi: 10.1177/2158244016638708
Belinchon-deMiguel, P., and Clemente-Suárez, V. J. (2018). Psychophysiological, body composition, biomechanical and autonomic modulation analysis procedures in an ultraendurance mountain race. J. Med. Syst. 42:32. doi: 10.1007/s10916-017-0889-y
Bellido, A., Ruisoto, P., Beltran-Velasco, A., and Clemente-Suárez, V. J. (2018). State of the art on the use of portable digital devices to assess stress in humans. J. Med. Syst. 42:100. doi: 10.1007/s10916-018-0955-0
Bustamante-Sánchez, Á., Delgado-Terán, M., and Clemente-Suárez, V. J. (2019). Psychophysiological response of different aircrew in normobaric hypoxia training. Ergonomics 62, 277–285. doi: 10.1080/00140139.2018.1510541
Bustamante-Sánchez, A., Loarte-Herradón, V. M., Gallego-Saiz, J. F., Trujillo-Laguna, T., and Clemente-Suárez, V. J. (2018). Psychophysiological response of fighter aircraft pilots in normobaric hypoxia training. Arch. Med. Deporte 35, 99–102. doi: 10.1080/00140139.2018.1510541
Chen, K.-J., Yang, C.-C., and Chiang, H.-H. (2018). Model of coping strategies, resilience, psychological well-being, and perceived health among military personnel. J. Med. Sci. 38, 73–80. doi: 10.4103/jmedsci.jmedsci_60_17
Clemente-Suárez, V. J. (2018). Periodized training achieves better autonomic modulation and aerobic performance than non-periodized training. J. Sports Med. Phys. Fitness 58, 1559–1564. doi: 10.23736/S0022-4707.17.07582-X
Clemente-Suárez, V. J., de la Vega, R., Robles-Pérez, J. J., Lautenschlaeger, M., and Fernández-Lucas, J. (2016). Experience modulates the psychophysiological response of airborne warfighters during a tactical combat parachute jump. Int. J. Psychophysiol. 110, 212–216. doi: 10.1016/j.ijpsycho.2016.07.502
Clemente-Suárez, V. J., Delgado-Moreno, R., González, B., Ortega, J., and Ramos-Campo, D. J. (2018). Amateur endurance triathletes’ performance is improved independently of volume or intensity based training. Physiol. Behav. S0031-9384, 30182–30183. doi: 10.1016/j.physbeh.2018.04.014
Clemente-Suárez, V. J., Diaz-Manzano, M., and Robles-Pérez, J. J. (2017a). Use of minicameras to improve operative procedure in security forces. J. Med. Syst. 41, 1–5. doi: 10.1007/s10916-017-0779-3
Clemente-Suarez, V. J., Palomera, P. R., and Robles-Pérez, J. J. (2018). Psychophysiological response to acute-high-stress combat situations in professional soldiers. Stress. Health 34, 247–252. doi: 10.1002/smi.2778
Clemente-Suarez, V. J., and Robles-Perez, J. J. (2013). Psycho-physiological response of soldiers in urban combat. An. Psicol. 29, 598–603. doi: 10.6018/analesps.29.2.150691
Clemente-Suárez, V. J., Robles-Pérez, J. J., and Fernández-Lucas, J. (2017b). Psychophysiological response in parachute jumps, the effect of experience and type of jump. Physiol. Behav. 179, 178–183. doi: 10.1016/j.physbeh.2017.06.006
Clemente-Suárez, V. J., Robles-Pérez, J. J., Herrera-Mendoza, K., Herrera-Tapias, B., and Fernández-Lucas, J. (2017c). Psychophysiological response and fine motor skills in high-altitude parachute jumps. High Alt. Med. Biol. 18, 392–399. doi: 10.1089/ham.2017.0071
Cohen, S., Kamarck, T., and Mermelstein, R. (1983). A global measure of perceived stress. J. Health Soc. Behav. 24, 385–396. doi: 10.2307/2136404
Coutts, A. J., Slattery, K. M., and Wallace, L. K. (2007). Practical tests for monitoring performance, fatigue and recovery in triathletes. J. Sci. Med. Sport 10, 372–381. doi: 10.1016/j.jsams.2007.02.007
Curiel-Regueros, A., Fernández-Lucas, J., and Clemente-Suárez, V. J. (2019). Effectiveness of an applied high intensity interval training as a specific operative training. Physiol. Behav. 201, 208–211. doi: 10.1016/j.physbeh.2019.01.009
Delgado-Moreno, R., Robles-Pérez, J. J., Aznar, S., and Clemente-Suarez, V. J. (2018). Inalambric biofeedback devices to analyze strength manifestation in military population. J. Med. Syst. 42:60. doi: 10.1007/s10916-018-0914-9
Delgado-Moreno, R., Robles-Pérez, J. J., and Clemente-Suárez, V. J. (2017). Combat stress decreases memory of Warfighters in action. J. Med. Syst. 41, 1–7. doi: 10.1007/s10916-017-0772-x
Diaz-Manzano, M., Fuentes, J. P., Fernandez-Lucas, J., Aznar-Lain, S., and Clemente-Suárez, V. J. (2018a). Higher use of techniques studied and performance in melee combat produce a higher psychophysiological stress response. Stress. Health 34, 622–628. doi: 10.1002/smi.2829
Diaz-Manzano, M., Robles-Pérez, J. J., Herrera-Mendoza, K., Herrera-Tapias, B., Fernández-Lucas, J., Aznar-Lain, S., et al. (2018b). Effectiveness of psycho-physiological portable devices to analyse effect of ergogenic aids in military population. J. Med. Syst. 42. doi: 10.1007/s10916-018-0945-2
Grossman, D., and Siddle, B. K. (2008). “Psychological effects of combat” in Encyclopedia of violence, peace, & conflict. 2nd Edn. ed. L. Kurtz (Academic Press), 1796–1805.
Hines, L. A., Sundin, J., Rona, R. J., Wessely, S., and Fear, N. T. (2014). Posttraumatic stress disorder post Iraq and Afghanistan: prevalence among military subgroups. Can. J. Psychiatr. 59, 468–479. doi: 10.1177/070674371405900903
Hormeño-Holgado, A. J., and Clemente-Suárez, V. J. (2019a). Psychophysiological monitorization in a special operation selection course. J. Med. Syst. 43:47. doi: 10.1007/s10916-019-1171-2
Hormeño-Holgado, A. J., and Clemente-Suárez, V. J. (2019b). Effect of different combat jet manoeuvres in the psychophysiological response of professional pilots. Physiol. Behav. 208:112559. doi: 10.1016/J.PHYSBEH.2019.112559
Hormeño-Holgado, A. J., Perez-Martinez, M. A., and Clemente-Suárez, V. J. (2019). Psychophysiological response of air mobile protection teams in an air accident manoeuvre. Physiol. Behav. 199, 79–83. doi: 10.1016/j.physbeh.2018.11.006
Iwata, N., and Buka, S. (2002). Race/ethnicity and depressive symptoms: a cross-cultural/ethnic comparison among university students in East Asia, North and South America. Soc. Sci. Med. 55, 2243–2252. doi: 10.1016/S0277-9536(02)00003-5
Kato, T. (2012). Development of the coping flexibility scale: evidence for the coping flexibility hypothesis. J. Couns. Psychol. 59, 262–273. doi: 10.1037/a0027770
Keramidas, M. E., Gadefors, M., Nilsson, L.-O., and Eiken, O. (2018). Physiological and psychological determinants of whole-body endurance exercise following short-term sustained operations with partial sleep deprivation. Eur. J. Appl. Physiol. 118, 1373–1384. doi: 10.1007/s00421-018-3869-0
Knapik, J. J., Bullock, S. H., Canada, S., Toney, E., Wells, J. D., Hoedebecke, E., et al. (2004). Influence of an injury reduction program on injury and fitness outcomes among soldiers. Inj. Prev. 10, 37–42. doi: 10.1136/ip.2003.002808
Poston, W. S. C., Haddock, C. K., and Heinrich, K. M. (2017). Is high intensity interval training safe for military? Mil. Med. 181, 627–637. doi: 10.7205/MILMED-D-15-00273.Is
Reed, D. J. (2016). Coping with occupational stress: the role of optimism and coping flexibility. Psychol. Res. Behav. Manag. 9, 71–79. doi: 10.2147/PRBM.S97595
Sánchez-Molina, J., Robles-Pérez, J. J., and Clemente-Suárez, V. J. (2017). Effect of parachute jump in the psychophysiological response of soldiers in urban combat. J. Med. Syst. 41:99. doi: 10.1007/s10916-017-0749-9
Sánchez-Molina, J., Robles-Pérez, J. J., and Clemente-Suárez, V. J. (2018). Assessment of psychophysiological response and specific fine motor skills in combat units. J. Med. Syst. 42:67. doi: 10.1007/s10916-018-0922-9
Scheier, M. F., Wrosch, C., Baum, A., Cohen, S., Martire, L. M., Matthews, K. A., et al. (2006). The life engagement test: assessing purpose in life. J. Behav. Med. 29, 291–298. doi: 10.1007/s10865-005-9044-1
Scherr, J., Wolfarth, B., Christle, J. W., Pressler, A., Wagenpfeil, S., and Halle, M. (2013). Associations between Borg’s rating of perceived exertion and physiological measures of exercise intensity. Eur. J. Appl. Physiol. 113, 147–155. doi: 10.1007/s00421-012-2421-x
Serrano, M. A., Salvador, A., González-Bono, E. G., Sanchís, C., and Suay, F. (2001). Relationships between recall of perceived exertion and blood lactate concentration in a judo competition. Percept. Mot. Skills 92, 1139–1148. doi: 10.2466/PMS.92.3.1139-1148
Tornero-Aguilera, J. F., and Clemente-Suárez, V. J. (2018). Effect of experience, equipment and fire actions in psychophysiological response and memory of soldiers in actual underground operations. Int. J. Psychophysiol. 128, 40–46. doi: 10.1016/j.ijpsycho.2018.03.009
Tornero-Aguilera, J. G., and Clemente-Suárez, V. J. (2019). Resisted and endurance high intensity interval training for combat preparedness. Aerosp. Med. Hum. Perform. 90, 32–36. doi: 10.3357/AMHP.5217.2019
Tornero-Aguilera, J. F., Robles-Pérez, J. J., and Clemente-Suárez, V. J. (2017). Effect of combat stress in the psychophysiological response of elite and non-elite soldiers. J. Med. Syst. 41:100. doi: 10.1007/s10916-017-0748-x
Tornero-Aguilera, J. F., Robles-Pérez, J. J., and Clemente-Suárez, V. J. (2018). Use of psychophysiological portable devices to analyse stress response in different experienced soldiers. J. Med. Syst. 42:75. doi: 10.1007/s10916-018-0929-2
Wolgast, M. (2014). What does the acceptance and action questionnaire (AAQ-II) really measure? Behav. Ther. 45, 831–839. doi: 10.1016/j.beth.2014.07.002
Keywords: military, perceived stress scale, combat, anaerobic training, endurance training
Citation: Hormeño-Holgado AJ, Nikolaidis PT and Clemente-Suárez VJ (2019) Psychophysiological Patterns Related to Success in a Special Operation Selection Course. Front. Physiol. 10:867. doi: 10.3389/fphys.2019.00867
Edited by:
Volker Scheer, Fondation de la Science des Sports Ultra, FranceReviewed by:
Ketty Milena Herrera-Mendoza, Costa University Corporation, ColombiaJuan Jaime Arroyo Toledo, University of the Faroe Islands, Faroe Islands
Copyright © 2019 Hormeño-Holgado, Nikolaidis and Clemente-Suárez. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Vicente J. Clemente-Suárez, [email protected]; orcid.org/0000-0002-2397-2801