In physically and cognitively demanding professions, individuals often face heightened risks of injury, illness, and attrition due to continuous exposure to various stressors. A recent longitudinal study published in the journal Stress and Health examined the cumulative incidence of these outcomes among candidates enrolled in the United States Army Special Forces Assessment and Selection (SFAS) course over a two-year period.
The study involved 792 candidates who completed psychological, sleep, and nutrition surveys upon enrollment. Additionally, anthropometric measurements and physical performance assessments were conducted, alongside the collection of fasted blood samples for physiological and nutritional biomarker analyses. Medical encounters and active-duty status were monitored for all candidates post-enrollment, regardless of their SFAS outcomes.
Logistic regression analyses were employed to identify baseline factors associated with the two-year incidence of injury, illness, or attrition. The findings revealed that slower road march times correlated with a 25%-66% increase in the odds of experiencing injury, mental or behavioral illness, sleep disorders, and separation from service. Conversely, factors such as greater resistance training, improved sleep quality, and higher protein intake were linked to an 18%-45% reduction in the odds of injury.
Interestingly, elevated morning cortisol levels at enrollment were associated with a 23% decrease in the odds of mental or behavioral illness. In contrast, negative mood, poorer sleep quality, and lower social support were each tied to a 28%-31% increase in the odds of separation from service.
This study highlights several modifiable factors that could be targeted to mitigate risks of injury and illness, ultimately enhancing resilience and retention in high-stress occupations. By focusing on physical training, nutrition, and psychological well-being, it may be possible to improve outcomes for individuals in demanding roles.
What this study does not show
This study does not establish causation between the identified factors and the outcomes of injury, illness, or separation from service.
Evidence scorecard
- Evidence class: primary_research
- Human status: unclassified
- Publication type: Journal Article