Oregano (

Military activities often involve high-intensity exercise that can disrupt antioxidant capacity. We investigated the effects of oregano supplementation on muscle damage, oxidative stress, and plasma antioxidant markers of soldiers performing the army combat readiness test (ACRT). Twenty-four healthy male soldiers (age: 24 ± 3 years, height: 167 ± 14 cm, mass: 66 ± 3 kg) were randomized into a placebo group (n = 12) or an oregano supplementation group (n = 12). The participants consumed a capsule containing 500 mg Origanum vulgare immediately after completing the ACRT. Blood sampling was taken before exercise, immediately after exercise, and 60 and 120 min after oregano consumption. Plasma levels of creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (TAC), and glutathione peroxidase (GPX) were measured at the four time points. The time × group interactions were found for CK (p < 0.0001, d = 3.64), LDH (p < 0.0001, d = 1.64), MDA (p < 0.0001, d = 9.94), SOD (p < 0.0001, d = 1.88), TAC (p < 0.0001, d = 5.68) and GPX (p < 0.0001, d = 2.38). In all variables, the difference between placebo and oregano groups were significant at 60 (p < 0.0001) and 120 (p < 0.0001) minutes after ACRT test. The main effect of time was also significant for all the variables (p < 0.0001). Our results suggest that oregano supplementation has the potential to reduce muscle damage and increase oxidative capacity following ACRT. Supplementation with oregano may serve as a dietary strategy to increase preparedness and promote recovery in military recruits.