Salivary steroids at rest and after a training load in young male athletes: relationship with chronological age and pubertal development

Puberty influences both the performance and the hormonal responses
to exercise-related stress.We evaluated the distribution
and the correlation between pubertal characteristics and the
salivary cortisol (sC) and testosterone (sT) responses to acute
physical exercise in young male athletes (13.4 ± 2.1 yr, n = 110).
The mean pre-exercise nmol· L–1 sC and sT concentrations were
19.08 ± 4.32 and 0.34 ± 0.15 and increased to 21.27 ± 5.51 and
0.41 ± 0.16 after a 90-min training session (p < 0.01). The sC concentration
at rest was positively correlated with chronological
age (p < 0.01) and negatively correlated with fat % (p < 0.05),
whereas significant negative correlations of ΔsC and ΔsC% after
exercise with age, pubertal stage and mean testis volume
(p < 0.05) were observed. The sT increase after exercise was correlated
with chronological age, pubertal stage and pre-exercise
sT levels (p < 0.01), whereas the ΔsT and ΔsT% of increase were
negatively correlated with chronological age and resting sT levels
(p < 0.05 and p < 0.01). In the present study, we observed the
presence of high inter–individual variability of different biological
parameters (anthropometry, pubertal stage, hormones, etc.)
within athletes selected by chronological age in the same class
and the presence of significant correlations between chronological
age, puberty and the steroid hormone responses to physical
exercise. Our data suggest the need for different criteria in exercise
prescription and selection of young athletes and in the evaluation
of stress reactivity at puberty.