Previously most studies indicated that high intensity training is a powerful stimulus to acute increases in blood testosterone hormone levels in males. The testosterone responses to exercise in females are controversial; while some studies have shown increases, others have suggested no change. The aim of this study was to determine alterations in serum concentrations of testosterone after an exhausting exercise in males and females. Eight physically active male students (age: 22.25 ± 1.49 yr; height 177.62 ± 1.87 cm; weight 74.97 ± 3.32 kg) and eight physically active female students (age: 19.87 ± 1.45 yr; height 161.87 ± 3.18 cm; weight 57.91 ± 7.33 kg) who were studying at School of Physical Education, Kastamonu University, voluntarily participated in this study. The subjects performed an incremental exercise test until exhaustion using a cycle ergometer (Monark, Stockholm, Sweden) at a constant pedal speed of 60 rpm with stepwise increments of 15 W every minute after a warm-up at 15 W for 3 min. The 5 cc. venous blood samples were obtained from an antecubital vein at pre and immediately after the exhaustion exercise. The Wilcoxon Signed Rank Test was used for determine the differences within groups results at a significance levels of p < 0.05. In conclusion, our study demonstrates that exhausting exercise has some effects on the total testosterone profile both males and females.