Blood pressure response to 1-month, electrolyte-carbohydrate beverage consumption

There are many occupations where workers undergo daily exposure to rigorous environments, often with only limited access to fluids. Such conditions warrant the use of an electrolyte rehydration beverage; however, the long-term use of such beverages may pose potential health risks due to the increase in dietary sodium intake. This study proposed to determine blood pressure response to daily electrolyte-beverage consumption during strenuous work in a group of young normotensive workers. Three groups of tree planters (mean age = 23 +/- 3 years, n = 51) were provided with electrolyte-beverage (3 mmol/L potassium, 18 mmol/L sodium), electrolyte-carbohydrate-beverage (addition of 333 mmol/L carbohydrate to electrolyte-beverage), or water at a rate of 500 mL/hour during the working day. Systolic and diastolic blood pressures were measured each week over the course of 23 working days (30 days total elapsed time). Planters spent 8.4 +/- 1.0 hours/day at heart rates of 124 +/- 10 b/min. There were no differences between the groups for volume of fluid consumed; however, the electrolyte beverages appeared to be more effective than water at maintaining hydration during planting. Daily sodium intake approximated estimated losses in all groups, with total intake lowest in the water group. Resting plasma volume expanded by approximately 4% in all groups, from the first to the 30th day. No changes were observed over time for systolic or diastolic blood pressure. One month of daily consumption of approximately 4.5 L of electrolyte-beverage or electrolyte-carbohydrate-beverage did not appear to affect resting blood pressure in young normotensive workers engaged in heavy physical work.