by Joel Martin, PhD, CSCS and Todd Miller, PhD, CSCS,*D, TSAC-F, FNSCA
Other
May 2026
The following is an exclusive excerpt from the NSCA’s Essentials of Tactical Strength and Conditioning, Second Edition, published by Human Kinetics. All text and images provided by Human Kinetics.
Exercise programs that incorporate high training volumes or high training intensities, especially those focused on single training modalities without variation, can increase the risk of OTS. The cumulative effect of intense physical training combined with other stressors such as inadequate nutrition, lack of sleep, and psychological stress contributes to the development of OTS. The imbalance between training load and recovery can be further exacerbated by external factors like work, personal life stress, and environmental conditions. Additionally, inadequate calorie intake relative to energy expenditure, leading to conditions such as Relative Energy Deficiency in Sport (RED-S) (49), can contribute to OTS (38).
Tactical athletes face a unique set of challenges that increase their risk of developing OTS (58). These challenges include the following:
OTS is preventable, and TSAC Facilitators play a crucial role in mitigating its risk. Preventing and mitigating OTS involve the following:
The symptoms of OTS are diverse, and the physiological markers of overtraining do not always parallel a decrease in performance (47). Such markers include increased resting heart rate, decreased maximal or submaximal exercise capacity, decreased immunoglobulin A (IgA) levels, changes in mood, and decreased testosterone-to-cortisol ratio. Due to the complexity and diversity of hormonal mechanisms and complications with their analysis, at present no definitive physiological markers can define OTS (38).
The outcomes of OTS can be severe and long-lasting. Full recovery often requires a substantial period of rest, ranging from several months to years (38). During this period, tactical athletes may experience persistent performance deficits, chronic health issues related to hormonal and immune function, and psychological disturbances such as depression and anxiety. Long-term outcomes of OTS may include the following:
For TSAC Facilitators who suspect OTS in a tactical athlete, referral to a health care provider, such as an athletic trainer or physician, is recommended. Many tactical athlete organizations, such as fire departments, have a supervising physician who oversees hiring and annual health assessments. Identifying OTS is challenging due to its multifaceted nature and the lack of specific evaluative tools. Key markers include persistent performance declines despite rest, mood disturbances and psychological symptoms, and hormonal imbalances, although these are not definitive (38). Due to the variability in symptoms and individual responses, no single assessment can confirm OTS conclusively. Notably, symptoms of RED-S overlap significantly with OTS, including impaired physiological function, decreased bone density, and hormonal disturbances (49). Longitudinal monitoring of performance and physiological parameters is essential for an accurate evaluation (38). TSAC Facilitators should refer an individual for professional medical evaluation if they observe persistent performance declines, unusual fatigue, mood changes, or physiological signs like elevated resting heart rate despite adequate rest. Despite the severity of OTS, recovery is achievable with appropriate management, which includes adequate rest, nutritional support, and psychological counseling. Effective management should prioritize the following: