Background: This study was aimed to investigate whether measurement of free testosterone and cortisol in saliva is a reliable alternative to their assessment in serum for monitoring physical fitness in professional athletes.
Methods: We studied 25 members of the soccer team Parma F.C., playing in Italian major football league. Blood and saliva samples were collected at fasting, before a regular training session. Cortisol, total and free testosterone, as well as the ratio between free testosterone and cortisol, were assessed in paired serum and saliva samples, and their results were compared.
Results: An excellent correlation was found between serum and saliva cortisol (r = 0.751; P < 0.001). A significant correlation was also observed between free testosterone in serum and saliva (r = 0.590; P = 0.002), whereas no significant correlation was found between total testosterone in serum and saliva (r = 0.181; P = 0.387). A significant correlation was found for the free testosterone to cortisol ratio in serum and saliva (r = 0.43; P = 0.031). All athletes (25/25; 100%) declared that they would feel more comfortable to have saliva rather than blood serially collected.
Conclusions: The results of this study suggest that measurement of free testosterone and cortisol in saliva may be seen as a reliable alternative to their assessment in serum.
Keywords: cortisol; free testosterone; saliva; sports; testosterone.
© 2016 Wiley Periodicals, Inc.