*4.5. Military Research Applications*

Five of the eleven studies included in this review quantified the effects of protein supplementation in those during military training, or in response to a military training-based activity [51,58–61]. Given the potential for concurrent endurance training to inhibit muscle strength adaptations [27,28], military recruits may be one population who can benefit from strategies which aim to promote gains in FFM and muscle strength during arduous concurrent military training. The findings of this systematic review sugges<sup>t</sup> that protein supplementation may be an effective strategy to support body composition and muscle strength development. However, to better understand the effects protein supplementation has on adaptation and performance outcomes of military recruits, additional population specific RCTs are needed. Future RCTs should consider investigating the effects of elevated protein intakes on training adaptations during arduous military training, including muscle strength, body composition and muscle recovery. Additionally, future work may want to consider adaptations not included in this review, such as bone adaptations, given that bone health and stress fracture incidence are important areas of military research [84–86] and which protein supplementation may be able to support [70,87]. The lack of women studied to date in this area also highlights a gap in the current literature. Therefore, future work should aim to include data in women since they now take-up more arduous (ground close combat) roles in the military [88]. Furthermore, including measures of protein metabolism, such as nitrogen balance and protein turnover, in future work should be considered as a means of better understanding the effects of protein supplementation during military recruit training.
