In this study, using the deuterium dilution technique, the hydration abilities of three kinds of sports drinks commercially available and drinking water (control group) under rest and exercise conditions were compared. The results showed that significant differences were found, in the rest state, including the time points as the absorption rate of the three beverages reached the maximum value, 50% of the maximum absorption rate, and the maximum absorption amount. However, no significant difference was found in the time when the absorption rate was 0. In the exercise status, a significant difference between the time when the absorption rate of drinking water and sports drinks reaches the maximum was also found. The results showed that the deuterium tracer labeling method could effectively measure the relative rate of ingested liquid being absorbed by the organism, and the replenishment capacity of the three kinds of commercial sports drinks was not significantly different from that of drinking water.