Introduction
Tactical athletes, such as military personnel, must maintain high levels of strength, endurance, power, and cognitive performance while operating under physically and mentally demanding conditions. Unlike traditional athletes, military personnel often train and perform while experiencing sleep deprivation, environmental stress, prolonged load carriage, and limited access to food. These conditions place substantial physiological stress on the body and increase the importance of proper nutrition for sustaining performance, promoting recovery, and maintaining operational readiness.
Macronutrients—carbohydrates, proteins, and fats—play essential roles in energy production, muscle repair, hormone regulation, and long-term physiological adaptation. Because tactical athletes are frequently exposed to intense training loads and periods of energy deficit, the quantity and distribution of these macronutrients can significantly affect both physical and cognitive performance.
Understanding how macronutrient intake affects tactical athletes is important for improving training outcomes, recovery, and overall readiness. Therefore, the purpose of this paper is to examine current research on how carbohydrate, protein, and fat intake influence athletic performance and physiological adaptation in tactical athletes such as military personnel.
The topic was selected due to the increasing physical demands placed on military personnel and the growing interest in evidence-based nutrition strategies that support performance and recovery. Understanding how macronutrient intake influences these outcomes can help improve training effectiveness and operational readiness in tactical populations.
Research
Carbohydrates and Tactical Performance
Carbohydrates serve as the body’s primary fuel source during moderate-to-high intensity exercise. They are stored as glycogen in skeletal muscle and the liver and are heavily relied upon during physically demanding activities such as sprinting, obstacle courses, load carriage, and combat drills. Because military training frequently involves repeated high-intensity tasks, adequate carbohydrate availability is essential for sustaining performance.
Research consistently demonstrates that low carbohydrate availability can impair physical performance. The joint position statement from the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine emphasizes that carbohydrate intake is critical for maintaining endurance capacity and repeated high-intensity performance (Thomas et al., 2016). When glycogen stores become depleted, fatigue increases and athletes often experience a higher perceived level of exertion during physical activity.
Research focused specifically on military populations has also highlighted the importance of carbohydrate intake. Sandberg (1999) examined carbohydrate loading in deploying military personnel and found that increased carbohydrate intake improved endurance performance during prolonged physical tasks. Although this study is older, it remains relevant because it directly examined nutritional strategies within a military environment.
More recent research reviewing nutrition strategies for tactical athletes also supports the importance of carbohydrate intake. Lye et al. (2025) emphasized that carbohydrates are critical not only for sustaining physical performance but also for maintaining cognitive function during demanding military operations. This is especially important because military personnel must maintain decision-making ability while experiencing physical and psychological stress.
Additional research examining nutrition strategies for tactical populations supports these findings. Gifford et al. (2021) reported that carbohydrate intake plays a key role in sustaining physical work capacity, maintaining cognitive performance, and delaying fatigue during prolonged military operations.
Overall, the literature strongly supports the role of carbohydrates as a primary energy source for tactical athletes and highlights their importance in maintaining both physical and cognitive performance.
Protein Intake and Muscle Adaptation
While carbohydrates primarily support energy production, protein plays a crucial role in recovery and physiological adaptation. Protein provides amino acids necessary for muscle repair, muscle protein synthesis, and the maintenance of lean body mass. These processes are especially important for military personnel who frequently experience muscle damage from repeated eccentric contractions, resistance training, and prolonged load carriage.
The International Society of Sports Nutrition position stands on protein and exercise provides widely accepted recommendations for protein intake in physically active individuals. According to this research, protein intake of approximately 1.6 to 2.2 grams per kilogram of body weight per day is generally recommended to support recovery and muscle adaptation during intense training (Jäger et al., 2017).
Experimental research has also examined protein intake during periods of caloric restriction. Longland et al. (2016) conducted a randomized controlled trial comparing higher and lower protein intake during a period of energy deficit combined with intense exercise. Participants were assigned to different protein intake groups while completing a structured training program. The results showed that individuals consuming higher protein levels gained more lean body mass and lost more fat mass compared to those consuming lower protein levels. Because this study used a randomized controlled design, the findings provide strong evidence that higher protein intake can support lean mass preservation during intense training and caloric restriction.
However, research conducted in military environments has produced mixed findings. Øfsteng et al. (2020) examined soldiers participating in a demanding military field exercise characterized by severe energy deficits. The study found that increasing protein intake did not significantly improve body composition or performance outcomes during the exercise. These findings suggest that when energy deficits become extremely severe, increasing protein intake alone may not fully offset the negative effects of inadequate energy availability.
Together, these studies indicate that protein intake plays an important role in recovery and lean mass preservation, but its effectiveness may depend on overall caloric intake and the operational conditions under which training occurs.
Dietary Fat and Hormonal Support
Dietary fat also contributes to overall performance and physiological health in tactical athletes. Fat plays an important role in hormone production, including testosterone, supports the absorption of fat-soluble vitamins, and provides energy during longer periods of lower-intensity activity.
Research suggests that extremely low-fat diets may negatively affect hormone levels and recovery. At the same time, diets that are excessively high in fat and low in carbohydrates may impair high-intensity performance because they reduce glycogen availability. For this reason, most sports nutrition guidelines recommend moderate fat intake, typically ranging from 20% to 35% of total energy intake (Thomas et al., 2016).
For tactical athletes, dietary fat may also be beneficial because it provides a dense source of calories that can be useful in field environments where food availability is limited. Maintaining adequate caloric intake is essential for preventing reductions in hormone production, immune function, and recovery capacity.
Energy Availability and Physiological Stress
One of the most important factors affecting performance in tactical athletes is overall energy availability. Military personnel often experience periods of low energy availability due to high training demands and limited access to food during field exercises.
Chronic energy deficits can lead to a variety of negative physiological outcomes, including decreased anabolic hormone production, increased injury risk, impaired immune function, reduced recovery capacity, and decreased cognitive performance. Ross et al. (2020) examined protein intake and performance outcomes in military populations and found that adequate energy intake plays a key role in maintaining strength, body composition, and injury prevention.
These findings emphasize that while macronutrient distribution is important, ensuring sufficient total caloric intake may be even more critical for maintaining performance and physiological health in tactical athletes.
Comparison of Research Findings
When comparing the findings across the literature, several consistent themes appear regarding macronutrient intake and tactical performance.
Most of the research agrees that carbohydrates play a critical role in maintaining endurance capacity and repeated high-intensity performance by sustaining glycogen availability (Thomas et al., 2016; Sandberg, 1999; Lye et al., 2025). These studies emphasize that when carbohydrate intake is insufficient, fatigue increases and both physical and cognitive performance may decline.
The research examining protein intake also shows general agreement regarding its importance for muscle recovery and lean mass preservation. Studies such as Longland et al. (2016) demonstrate that higher protein intake during periods of intense training and caloric restriction can help maintain or increase lean body mass. In contrast, research conducted in real military environments suggests that increasing protein intake alone may not always improve performance outcomes if overall energy intake remains too low (Øfsteng et al., 2020).
Another common theme across the literature is the importance of total energy availability. While each macronutrient serves a distinct physiological role, several studies emphasize that maintaining adequate caloric intake may be more important than adjusting macronutrient ratios alone (Ross et al., 2020). When tactical athletes experience prolonged energy deficits, negative effects such as decreased recovery, increased injury risk, hormonal disruption, and impaired cognitive performance can occur regardless of macronutrient distribution.
Overall, the research supports the importance of balanced macronutrient intake while emphasizing that adequate total energy intake is essential for maintaining performance and supporting physiological adaptation in tactical athletes.
Conclusion
The research reviewed in this paper demonstrates that macronutrient intake significantly influences both athletic performance and physiological adaptation in tactical athletes such as military personnel.
Carbohydrates support high-intensity exercise performance and cognitive function by maintaining glycogen availability. Protein supports muscle repair, muscle protein synthesis, and the preservation of lean body mass during periods of intense training. Dietary fat contributes to hormone production and provides an additional source of energy during prolonged activity.
Although each macronutrient has a unique role, the literature consistently shows that adequate overall energy intake is essential for maintaining performance and recovery. Studies examining protein intake during severe energy deficits demonstrate that increasing protein intake alone may not fully prevent performance declines if total caloric intake remains insufficient.
Overall, balanced macronutrient intake combined with adequate energy availability appears to be the most effective nutritional strategy for supporting both performance and long-term physiological adaptation in tactical athletes.
Real-World Application
The findings from this research have important practical implications for military training and operational environments.
Nutrition programs for tactical athletes should emphasize maintaining adequate total caloric intake while adjusting macronutrient distribution based on training demands.
Higher carbohydrate intake may be beneficial during periods of high-volume endurance training or prolonged field exercises
Increased protein intake may support recovery and lean mass preservation during strength training phases or moderate energy deficits
Adequate dietary fat intake should be maintained to support hormone production, vitamin absorption, and overall physiological health
Ensuring that tactical athletes consume sufficient carbohydrates, protein, and dietary fat can help maintain physical performance, improve recovery, and support operational readiness.
References
Gifford, R. M., Todisco, T., Stacey, M., & Wentz, L. M. (2021). Nutritional considerations for performance in tactical populations. Journal of the International Society of Sports Nutrition, 18(1), 55.
Jäger, R., Kerksick, C. M., Campbell, B. I., Cribb, P. J., Wells, S. D., Skwiat, T. M., Purpura, M., Ziegenfuss, T. N., Ferrando, A. A., Arent, S. M., Smith-Ryan, A. E., & Antonio, J. (2017). International Society of Sports Nutrition position stand: Protein and exercise. Journal of the International Society of Sports Nutrition, 14, 20. https://doi.org/10.1186/s12970-017-0177-8
Longland, T. M., Oikawa, S. Y., Mitchell, C. J., Devries, M. C., & Phillips, S. M. (2016). Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: A randomized trial. The American Journal of Clinical Nutrition, 103(3), 738–746.
Øfsteng, S. J., Garthe, I., Jøsok, Ø., Rønnestad, B. R., & Anderssen, S. A. (2020). No effect of increasing protein intake during military field exercise with severe energy deficit on body composition and performance outcomes. Scandinavian Journal of Medicine & Science in Sports, 30(3), 571–581.
Ross, J. A., Mankowski, R. T., & McClung, J. P. (2020). Dietary protein intake and strength outcomes in military populations: Implications for performance and injury risk. Military Medicine, 185(Suppl. 1), 430–437.
Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics, 116(3), 501–528.
Lye, J. C. T., et al. (2025). Nutrition for tactical athletes: Insights, applications, and future directions. Sports Medicine.
