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Changes in salivary biomarkers after physical activity in football players

The first findings of our joint research with UZGENT and ACTA will be published soon. Here’s already the abstract:

Kouvaras I1, Bizzarro S1, Ligtenberg AJM2, Solleveld H3, Goedhart A3, Laine ML1, Vanden Bossche L4.
1 Department of Periodontology, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, The Netherlands.
Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, The Netherlands.
3 SportsInjuryLab, Dronten, The Netherlands
4 Department of Physical Rehabilitation and Sports Medicine, Ghent University Hospital, Belgium



Professional football players are expected to perform optimally and therefore their health and fitness are closely monitored. However, high stress levels and poor oral health in athletes are common findings, and both can affect performance and injury incidence. Saliva, as an easy-to-collect liquid biopsy, could be used to monitor athletes’ response to stress from physical activity.


The main objective was to study changes in salivary cortisol levels before and after a regular training session. Furthermore, changes in other salivary biomarkers and the response to similar training sessions at two different stages of the soccer season, winter and summer, were studied. Finally, the oral health condition of the footballers was assessed.

Materials and Methods

Professional football players (age >18 years) from two U21 teams in Belgium were recruited. Oral rinses before and after two afternoon training sessions were collected. Oral examination was carried out before the winter training. ELISA, capillary electrophoresis and enzymatic fluorescence measurements were used to determine salivary cortisol, protease, amylase, lactate, ammonium, potassium, sodium, magnesium and calcium as markers for stress and physical performance.


In winter (n=36), a significant increase was found after training for saliva levels of cortisol (p=0.001), protease (p=0.001) and sodium (p=0.002). In summer (n=15), only magnesium (p=0.014) and calcium (p=0.012) showed significant increases. Significant seasonal differences in response to exercise were found for sodium and calcium (p<0.05). Considerable inter-individual variability among the players in the response to physical activity was noted. On average, the players showed suboptimal oral health, with high prevalence of caries, erosion, gingivitis and periodontitis.


Physical exercise affects salivary biomarkers. Athletes need to improve their oral health. Inter-individual variability in the response to physical activity should be further investigated in relation to performance and risk of injuries