Energy drink consumption by athletes has become increasingly popular. The aim of this study was to determine the effect of phantom and dragon energy drinks on female athlete students. For this purpose, twelve female athlete students of Tehran University (age 22+0.63 years, height 162.1+5.8 cm, weight 56.91+6.79 kg) volunteered to participate in this study and performed three sessions of a Bruce treadmill test with 4-day intervals. In each session, in a double-blind, randomized and counterbalanced design, 6 ml/kg/bw of phantom, dragon or placebo was consumed 40 minutes before the exercise test. Results showed that dragon and phantom consumption resulted in a significant difference between VO2max, time of exhaustion and perceived exertion in the posttest (P<0.05). There was no significant difference in pretest HR between the two drinks (p>0.05). Dragon significantly increased HRmax when compared to phantom and placebo (P<0.05). In conclusion, the acute consumption of phantom and dragon drinks probably has ergogenic effects on some cardiovascular factors.