Author(s): PRATS-PUIG, A., ÁLVAREZ-HERMS, J., JÒDAR-PORTAS, A., VASILEVA, F., FERRUSOLA-PASTRANA, A., HOMS-ÀVILA, J., Institution: EUSES, Country: SPAIN, Abstract-ID: 2428

INTRODUCTION:
Salivary pH has been related to athletic performance as a proxy of body’s metabolic responses during physical exertion. However, studies in children analysing the association between salivary pH with physical activity and physical fitness are scarce. The purpose of this study was to investigate the relationship between physical activity, fitness, and salivary pH in schoolchildren.
METHODS:
Eighty-seven primary schoolchildren were included in the study. Salivary pH was obtained using a universal indicator pH paper test (One+Step). Minutes per day spent in moderate-to-vigorous physical activity (MVPA) were measured with a triaxial accelerometer (Actigraph) and used to create and compare tertiles. Physical fitness was assessed by the handgrip strength (handgrip dynamometer) and agility (10 × 5 m shuttle run test). The collected data was analysed by SPSS version 29.
RESULTS:
We found a significant inverse correlation between time spent in MVPA and salivary pH (r = -0.398, p < 0.001). Children with lower MVPA levels (36.37 ± 0.86 minutes/day) had salivary pH levels 15% higher than more active children (86.39 ± 15.29 minutes/day), with mean pH values of 7.11 ± 0.86 and 6.17 ± 0.70, respectively. Interestingly, salivary pH also correlated with physical fitness measures, exhibiting a negative association with handgrip strength (r = -0.348, p < 0.001) and a positive association with time to complete the 10 x 5m shuttle run test (r = 0.267, p = 0.038). Linear regression analysis, using physical activity and fitness measures as independent variables, revealed that only MVPA showed a significant negative association with salivary pH (β = -0.345, p = 0.005). The adjusted R-squared for the model was 17.9%.
CONCLUSION:
Taken together, our results show that a more alkaline salivary pH was related to lower physical activity levels. Moreover, children with lower MVPA levels had salivary pH levels 15% higher than more active children. These findings may help the monitorization of practicing more physical activity to optimize health. Finally, salivary pH may be a non-invasive and useful health indicator, which is especially important for the paediatric population.