This study aims to explain the VO2 max value in adolescents and the differences in lymphocytes and eosinophil levels after moderate aerobic exercise. The study was conducted with a post-test only control group design on 15 basketball player students and 15 non-basketball player students at SMAN 1 Banjarbaru. The sampling technique was carried out by using purposive sampling method. Measurement of VO2 max value was executed on the first day with MFT (Multistage Fitness Tes / Bleep Test) and measurement of lymphocytes and eosinophil levels was executed on the third day by trained medical personnel after the subject did the moderate aerobic exercise. Data analysis used was the Mann-Whitney test for VO2 max value and Saphiro-Wilk test for lymphocytes and the Mann-Whitney test for eosinophil levels. The results of the data analysis is the VO2 max value between groups were significantly different (p = 0.000) and there were no difference in lymphocytes (p > 0.05) and eosinophil (p > 0.05) count between groups after the moderate aerobic exercise. We conclude that basketball players student have a better VO2 max value than non-basketball players and moderate aerobic exercise were unable to make any significant difference between the groups in the number of lymphocytes and eosinophils