Modulatory Role of Pre-exercise Water Ingestion on Metabolic, Cardiovascular and Autonomic Responses to Prolonged Exercise in Young Mildly Active Male Students

Studies have indicated deranged post-exercise physiological responses in hypohydrated subjects. The study investigated the effect of pre-exercise water ingestion on metabolic, autonomic and cardiovascular responses to prolonged exercise in mildly active male Nigerian students. 36 mildly active young males who emerged from random sampling were assigned into exercise groups I, II and III and were administered 0 L, 0.5 L and 1 L of drinking water at 15°C respectively. Responses were evaluated as % change between post- and pre-exercise levels and statistical analysis was conducted using SPSS-23. When compared with group I, baroreflex sensitivity (BRS), pulse rate (PR), systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), mean arterial blood pressure (MAP), rate pressure product (RPP), double product (DoP), Calculated Cardiac Output (CCO) and Peripheral Oxygen Saturation (SP02) responses were significantly raised in groups II and III. Alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) responses were significantly lower in group III when compared with group I or group II. Peak PR, DoP and CCO responses occurred in group II while ALT, AST and ALP responses reached the nadir in group III. As far as groups II and III were concerned, hematocrit, hemoglobin and RBC responses did not significantly differ from group I but BRS positively and negatively correlated with DoP (r=0.952, P<0.05) and SPO2 (r=-0.568, P<0.05) respectively in both groups. In conclusion, the study showed that ingestion of 1 liters of water prior to prolonged exercise modulated neurovascular, cardiovascular and metabolic responses to prolonged exercise in mildly active male students.