Maximal oxygen uptake ( \(\dot{V}{\text{O}}_{2\max }\) ) is one of the measures used to assess aerobic power, which is both negatively related to mortality and positively related to swimming performance. Aging acts directly on the decrease in \(\dot{V}{\text{O}}_{2max}\) , both in sedentary people and in athletes. Given the marked growth in the population of master swimmers and the lack of data on \(\dot{V}{\text{O}}_{2\max }\) in these swimmers, the present study aimed to compare the \(\dot{V}{\text{O}}_{2\max }\) parameters, in different age groups, of competitive master swimmers in swimming. The sample consisted of 22 master swimmers, divided into three groups by age (G1: 32.6 ± 2.9; G2: 44.8 ± 2.4; G3: 64.1 ± 8.0 years). Anthropometric and body composition measurements were taken prior to pool assessment. Oxygen uptake, heart rate (HR), blood lactate concentration ([La]), and rating of perceived exertion were recorded during an incremental intermittent n × 200 m front crawl test. Descriptive and inferential statistics were applied (alpha = 0.05). Although age demonstrated a large effect size on the variables, no significant differences were found between groups for \(\dot{V}O_{2max}\) (G1: 49.2 ± 6.2; G2: 43.4 ± 4.2; and G3: 39.6 ± 9.8 ml∙kg∙min−1), and for maximal [La] (G1: 10.0 ± 4.0; G2: 9.2 ± 2.2; and G3: 7.4 ± 2.4 mmol∙l−1). On the other hand, the maximal HR reached was lower in G3 (149.0 ± 9.5 bpm) than in G1 (177.1 ± 7.2 bpm) and G2 (168.6 ± 10.4 bpm). Despite the age-related decrease in physiological parameters affecting oxygen uptake, the dispersion of the \(\dot{V}O_{2max}\) data indicates the presence of other aspects to be considered beyond the age in these results, such as heterogeneity in swimming experience.
