Background There are growing interests in using dietary supplements to improve athletic performance. This study aimed to evaluate the effect of the food ration bar enriched with β-alanine, L-arginine, and Nigella sativa on athletic performance and inflammation following intense military training. Methods This double-blind, randomized, controlled clinical trial was conducted on 54 new cadets. Eligible participants were randomly assigned in a 1:1 ratio to receive food ration bars enriched with arginine (2 g/day), β-alanine (2 g/day), and Nigella sativa (2 g/day) or nonenriched food ration bars during a 2-week military training. Aerobic and anaerobic performances were evaluated by the Cooper and RAST tests, respectively. Results A significant increase in anaerobic powers (min, mean, and max) and a significant reduction in fatigue index were observed in the intervention group as compared to the control group, even after the adjustment for confounding factors. Also, increased levels of hs-CRP and TNF-α following military training were significantly lower in the intervention group as compared to the control group (hs-CRP: 0.55 ± 0.1 versus 2.43 ± 0.1 mg/L; p-value: 0.01; TNF-α: 0.12 ± 0.04 versus 0.62 ± 0.04 pg/ml; p-value: 0.03). No significant changes were observed in VO2 max in both groups. Conclusions Our results showed that the combination of β-alanine, L-arginine, and Nigella sativa can improve anaerobic performance and reduce inflammation following intense physical activities. Further studies with long-term duration are needed to confirm the cumulative/synergic effects of these ingredients in trained and nontrained subjects.

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