Creatine hydrochloride or creatine monohydrate plus resistance training: which combination has a greater effect on oxidative stress, muscle damage, performance, and body composition in soldiers?

This study aimed to compare the effect of creatine hydrochloride (Cr-HCl) and creatine monohydrate (CrM) supplementation alongside resistance training (RT) on oxidative stress, muscle damage, performance, and body composition in soldiers. In this research, 36 male soldiers aged 18–28 years voluntarily participated in the study. Participants were randomly divided into three groups (n = 12): 1- RT + Cr-HCl, 2- RT + CrM, and 3- RT + placebo (PL). The participants performed RT with an intensity of 70–85% 1RM for eight weeks (three days a week). Also, during this period, they used Cr-HCl and CrM supplements. Before and after supplementation and training periods, body composition (percent body fat (PBF) and skeletal muscle mass (SMM)), performance (muscular strength, muscular endurance and power), blood sample (total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), lactate dehydrogenase (LDH), Creatine kinase (CK)) were taken. The results showed that muscle strength, muscle endurance, power and SMM increased while PBF decreased in the RT + Cr-HCl and RT + CrM groups compared to the PL group (P ≤ 0.05). In addition, regarding antioxidant indices changes, the results showed decreased MDA and increased SOD in RT + Cr-HCl and RT + CrM groups compared to the RT + PL group (P ≤ 0.05). However, no significant group × time interactions were noted for levels of LDH and CK (P > 0.05). In general, the results showed that Cr-HCl and CrM, along with RT can positively affect oxidative stress, performance and body composition of soldiers, but it does not affect muscle damage indicators. According to the results, Cr-HCl does not cause more effects than CrM.