The anabolic hormone testosterone (T) continues to be researched extensively in exercise studies, with blood serum or plasma samples collected routinely. This method is considered both valid and reliable; however, the collection process can be invasive and difficult during exercise. For this reason, non-invasive sampling, such as saliva collections, is increasing in popularity.
Purpose: To investigate the association between salivary and serum T before and after various intensities of exercise to assess the validity of saliva collection for T measurement.
Methods: 12 endurance-trained males (Mean ± SD; VOVO2max 58.2 ± 6.4 ml/kg/min, 22 ± 4.6 years, BMI 21.6 ± 1.9) completed three 30-minute exercise (cycling) sessions at 40% (Low), 60% (Moderate), and 80% (High) of VO2max as well as a 30-minute resting Control session on four separate days. Salivary (s) and serum (S) samples were assessed for T prior to (Pre), immediately post (Post), and 30 minutes post (30 Min Post) each session.
Results: Low exercise caused a significant (p<0.05) increase in ST, but not sT, while Moderate and High exercise caused an increase (p<0.01) in both ST and sT. A strong positive correlation (Spearman [rs]) existed between sT and ST in the Moderate (rs = 0.912 [p<0.001; n=36; 12 subjects x 3 measurement times-samples]), and High (rs = 0.898 [p<0.001]) sessions, but not as strong for the Low (rs = 0.517 [p=0.001]) session.
Conclusions: These results suggest that sT and ST levels are strongly associated to exercise. However, the exercise-related sT and ST responses-changes were more closely aligned at Moderate and High intensities, suggesting a greater validity between the saliva and serum responses to higher intensity exercise.