Purpose: Individuals who exercise commonly consume commercial beverages for rehydration and performance maintenance. Nevertheless, differences in carbohydrate and sodium content can influence hydration efficacy. This study aims to compare the effects of demineralized water (DW), sweetened tea (ST), and electrolyte-containing beverage (EB) on rehydration after exercise-induced dehydration. Methods: A three-way, randomized, crossover design was applied in nine healthy male participants (age, 24.9 ± 1.8 years; body mass index, 21.1 ± 0.9 kg/m 2 ). Participants performed cycling exercise in a hot environment to induce approximately 2% body mass loss during the dehydration stage. During the rehydration stage, participants consumed DW, ST, or EB in volumes equivalent to body mass loss under temperature-controlled conditions. ST contained 7.8% carbohydrate and 1.59 mEq/L sodium; EB contained 3.8% carbohydrate and 23.73 mEq/L sodium, while DW contained neither. Hydration status was assessed using body mass, blood, and urine parameters. Results: Participants lost 2% of body mass within 84.4 ± 8.5 minutes. During the rehydration stage, plasma volume increased earlier in the EB group, with a significant increase observed at 60 minutes (5.4 ± 5.0%, p < 0.05). Blood sodium levels in the DW group were significantly lower than those in the ST and EB groups at 60 minutes and remained lower than in the EB group until 180 minutes (p < 0.05). The EB group exhibited a higher median fluid retention (86.6 [66.5; 91.0]) than the DW group (84.3 [65.5; 89.7]) and ST group (83.8 [75.7; 87.9]), but these differences were not significant. Conclusion The EB group showed earlier plasma volume recovery than the DW and ST groups, and maintained higher blood sodium levels than the DW group. These findings suggest a supportive role of EB in early post-exercise rehydration and electrolyte balance.Future studies should investigate the effects of increased fluid volumes and prolonged rehydration durations.