Introduction: Muscle oxygen saturation and total hemoglobin are important for athletes because of effects on fatique and performance parameters. The purpose of present study is to examine muscle oxygen saturation and total hemoglobin levels at different intensities in highly trained adolescents. Method: Fourty-four highly trained adolescents (20.18±2.11 years; 73.02±12.20 kg; 180.00±8.03 cm) voluntarily participated this study. A standard general warm-up and later a special warm-up for the lower extremity were applied to the subjects before the measurements. Incremental Cycling Exercises were performed by Monark LC4. Smo2 and THb were evaluated by Moxy Oxygen Monitor. Height was assessed by using a wall-mounted stadiometer. Normality and sphericity tests were done using Kolmogorov-Smirnov and Mauchly’s test, respectively. Outliers were determined using boxplots. Descriptive statistics include mean (M) and SDs. To see differences among intensities, Repeated Measure Anova test was used. We analyzed relationship between body composition variables and Smo2 & THb by Pearson correlation test. In all analyzes of the data, the significance level was accepted as p<0,05. Discussion and Conclusion: there was significantly difference both Smo2 and THb values. Smo2 values decreased when exercise intensity increased. In contrary to Smo2 values, THb values increased as intensity increased. But THb values in rest and warm up intensity have no significantly difference. Besides, Smo2 values have significantly positive correlation with body weight. On the other hand, THb values also have negatively significant correlation with body weight, body mass index and body fat.