Abstract
In six male physically active subjects the adrenocortical and metabolic changes in
response to incremental exercise testing were investigated. Blood and saliva samples
were taken at rest, at the end of every workload (duration 4 min with 50 W increment),
immediately and 10 min after 1 min all out spurt on the electrically braked cycle
ergometer. Both saliva and serum cortisol were measured as well as blood lactate.
The cortisol response in serum and in saliva showed similar dynamics (r = 0.86, p
< 0.001, n = 50) at submaximal work. At maximal work the serum cortisol concentration
showed a transitory decrease, which was not manifested in saliva. It is hypothesized
that a factor related to the metabolic acidosis masks the actual adrenocortical response
in the serum but not in saliva. Correlation analysis revealed a positive relation
between lactate and cortisol in serum (r = 0.56, p < 0.01, n = 50) and saliva (r =
0.70, p < 0.01, n = 50). Apparently, salivary cortisol closely reflects plasma free
cortisol level, presenting advantage over total cortisol measurements. Moreover salivary
measurement will permit studies in their authentic settings and should assist attempts
to understand the nature of the adrenocortical function in exercise.
Key words
Salivary and serum cortisol - exercise testing - metabolic acidosis
