A cross-sectional comparative study of cardiorespiratory endurance and related parameters in athletes and sedentary young adults (18–25 years) using a ramp bicycle protocol

Background: Maximal oxygen uptake (VO 2 max) and related cardiopulmonary parameters are key indicators of cardiovascular fitness. Ramp incremental exercise protocols allow continuous workload progression and may better discriminate differences between trained and untrained individuals. Objective: To compare VO 2 max, VO 2 /kg, maximal workload, maximal heart rate (MHR), blood pressure, oxygen saturation, oxygen pulse, and respiratory exchange ratio (RER) between athletes and sedentary young adults aged 18–25 years. Materials and Methods: In this cross-sectional study, 40 healthy male participants aged 18–25 years were recruited and classified as athletes (≥2.5 h/week structured training) or sedentary (<2.5 h/week physical activity). All participants underwent a standardized bicycle ramp protocol to volitional exhaustion with continuous cardiopulmonary monitoring. Group differences were analyzed using independent-samples t -tests. Results: Athletes demonstrated significantly higher VO 2 max (1.89 ± 0.66 vs. 1.59 ± 0.60 L/min, P = 0.041) and maximal workload (155.87 ± 22.39 vs. 138.95 ± 45.22 W, P = 0.037). Heart rate recovery and systolic blood pressure differed significantly between groups, whereas MHR, oxygen saturation, and oxygen pulse showed no statistically significant differences. RER at maximal exertion was marginally higher in athletes ( P = 0.049). Conclusion: The ramp protocol effectively differentiates cardiorespiratory performance between athletes and sedentary young adults, highlighting training-related central and peripheral adaptations.