Abstract
We investigated the response of salivary total protein (TP), alpha-amylase (sAA) and
chromogranin A (CgA) to sporting competition and their relation with positive and
negative affect. 11 professional swimmers were examined during the first day of a
national contest and on a recreated event that matched time-of-the-day and day-of-the-week
assessments 2 weeks later. Total protein was determined by the Bradford method and
sAA and CgA by Western blotting upon awakening, 30 and 60 min post awakening, immediately
before warming up for competition and 5, 20 and 60 min after competition. Psychometric
instruments included the Positive Affect and Negative Affect Schedule-X. The concentrations
of TP, sAA and CgA differed from controls only prior to and 5 min after the event.
We observed positive correlations between higher negative affect scores with higher
levels of TP, sAA and CgA prior to the event on the competition day. All 3 markers
showed a similar reactivity to sporting competition, which may be attributed to the
mechanisms responsible for protein secretion into saliva when collection is performed
with no exogenous stimulation. TP is an attractive marker in sports psychology since its determination is faster
and cheaper than traditional kinetic or immune assays.
Key words
saliva - exercise - stress - biomarker
