Salivary pH increases after jump exercises in hypoxia

Abstract

Summary Objectives The purpose of the present study was to determine if high intensity exercise performed in hypoxia could affect the salivary pH response in comparison to normoxia. Methods Eight healthy and physically active subjects performed a randomized single blinded protocol consisting in six sets of 15 seconds stretch-shortening-cycles (SSC) jumping at three different conditions: (T1) baseline test at 550 m altitude, (T2) at 2500 m simulated altitude (O 2 = 16.4%), and (T3) at 4000 m simulated altitude (O 2 = 13.4%). Non-stimulated whole saliva samples were collected for all subjects before and after the exercise. Blood lactate, oxygen saturation and heart rate were measured to assess the anaerobic character of the test. Results The results revealed an increase in salivary pH values after the exercise, only reaching significance for altitude conditions (T2, P = 0.009; T3, P = 0.026). No significant differences in blood lactate were detected when comparing the three experimental conditions. Conclusions Our results suggest that exercise performed in normobaric hypoxia has stronger effects in saliva alkalinization than when performed under normoxia. As salivary pH is strongly associated with caries incidence, more research is needed to assess the clinical significance of changes in salivary pH due to intense exercise in normobaric hypoxia.