Background: Maximum oxygen consumption (VO2 max) is an indicator of the basic concept of physical fitness (physical fitness). The factors that determine VO2 max include heart lung function, age, aerobic muscle metabolism, body obesity, exercise state, genetics, gender, multivitamins. The age of 20-30 years is the peak age of heart and lung endurance, then it will decrease due to increasing age, the person will reduce various sports activities. Methods: This study was conducted to determine differences in VO2 Max in riverbank communities in HST Regency based on age, sex, and cellular immunity (neutrophils and lymphocytes). The samples used were 30 samples each based on adult and elderly age, sex, and neutrophil and lymphocyte examination results. Sampling using simple random sampling on samples that meet the inclusion criteria. VO2 Max is measured by the Rockport method. Data analysis used unpaired t test if the data were normally distributed and Mann Whitney if the data were not normally distributed with a confidence level of 95%. Results: VO2 max values for the less fit and fit men group were 35.7% and 64.3%, respectively. Meanwhile, the VO2 max value for the less fit and fit women group was 62.5% and 37.5%, respectively. The p value of both groups is 0.03. The neutrophil mean of the less fit and fitter groups were 63.5 and 59.1, respectively. The neutrophil mean for the less fit and fitter groups were 27.6 and 31.1, respectively.Conclusion: There are significant differences in VO2 max in groups of women and men, adults and elderly residents of Hulu Sungai Tengah Regency, South Kalimantan. In addition, there was also a significant difference in the percentage of neutrophils and lymphocytes between the VO2 max fitter and less fitter groups.