The biggest determinants of success in elite military training are not physical factors but psychological factors, according a small study conducted among US Marine Corps trainees.
The US military has a constant need for service members who can serve in elite and specialised military units, such as the Marine Corps. However, because the training courses for these forces is so rigorous, the dropout rate is high. To help determine predictors of success or failure in elite military training, Dr Leslie Saxon, executive director of the University of Southern California (USC) Centre for Body Computing, and fellow Centre for Body Computing researchers monitored the physical and psychological activity of three consecutive classes of Marines and sailors enrolled in a 25-day specialised training course.
A total of 121 trainees participated. Only slightly more than half (64) successfully completed the course.
Researchers found there was no correlation between finishing and performance on physical training standards, such as hikes or aquatic training. Physical markers such as heart rate or sleep status also did not play a role.
Rather, the biggest determinant was mental. Trainees who identified themselves as extroverted and having a positive affect – the ability to cultivate a joyful, confident attitude – were most likely to complete the course.
"These findings are novel because they identify traits not typically associated with military performance, showing that psychological factors mattered more than physical performance outcomes," says Saxon, who is also a cardiologist with Keck Medicine of USC and a professor of medicine (clinical scholar) at the Keck School of Medicine of USC. Researchers were also able to pinpoint psychological stressors that triggered dropping out of the course. Trainees typically quit before a stressful aquatic training exercise or after reporting an increase in emotional or physical pain and a decrease in confidence. This led researchers to be able to predict who would drop out of the course one to two days in advance.
While Saxon has been studying human performance in elite athletes for 15 years, this was her first study involving the military. She partnered with the USC Institute for Creative Technologies, which has established military research programs, to run the study with a training company in Camp Pendleton, California that trains Marines in amphibious reconnaissance. Typically, only around half of the participants finish the training.
The study authors collected baseline personality assessments of the trainees before the recruits began the course, assessing personality type, emotional processing, outlook on life and mindfulness. Researchers next provided subjects with an iPhone and Apple Watch, and a specially designed mobile application to collect continuous daily measures of trainees' mental status, physical pain, heart rate, activity, sleep, hydration and nutrition during training.
The mobile application also prompted trainees to answer daily surveys on emotional and physical pain, well-being and confidence in course completion and instructor support. "This study, the first to collect continuous data from individuals throughout a training, suggests that there may be interventions the military can take to reduce the number of dropouts," says Saxon. "This data could be helpful in designing future training courses for Marines and other military units to increase the number of elite service members, as well as provide insights on how to help athletes and other high performers handle challenges."
Saxon is already testing whether or not various psychological interventions or coaching might encourage more trainees to stay the course.
Background: Specialized training for elite US military units is associated with high attrition due to intense psychological and physical demands. The need to graduate more service members without degrading performance standards necessitates the identification of factors to predict success or failure in targeted training interventions.
Objective: The aim of this study was to continuously quantify the mental and physical status of trainees of an elite military unit to identify novel predictors of success in training.
Methods: A total of 3 consecutive classes of a specialized training course were provided with an Apple iPhone, Watch, and specially designed mobile app. Baseline personality assessments and continuous daily measures of mental status, physical pain, heart rate, activity, sleep, hydration, and nutrition were collected from the app and Watch data.
Results: A total of 115 trainees enrolled and completed the study (100% male; age: mean 22 years, SD 4 years) and 64 (55.7%) successfully graduated. Most training withdrawals (27/115, 23.5%) occurred by day 7 (mean 5.5 days, SD 3.4 days; range 1-22 days). Extraversion, positive affect personality traits, and daily psychological profiles were associated with course completion; key psychological factors could predict withdrawals 1-2 days in advance (P=.009).
Conclusions: Gathering accurate and continuous mental and physical status data during elite military training is possible with early predictors of withdrawal providing an opportunity for intervention.
Leslie Saxon, Brooks DiPaula, Glenn R Fox, Rebecca Ebert, Josiah Duhaime, Luciano Nocera, Luan Tran, Mona Sobhani