Does a sports drink lower your pulse rate during exercise compared to plain water? Gatorade contains electrolytes (salts that replace what you lose through sweat). Plain water does not. But does that difference show up in your heart rate? You give one group of subjects 250 ml of Gatorade and wait 20 to 40 minutes. Then they rest for two minutes while you take their carotid pulse at the neck. Next, they do eight-inch step-ups for four minutes and you measure again. On a different day, the same subjects repeat the test with plain water instead. Compare resting and exercising pulse rates between the two drinks to find out whether electrolytes make a measurable difference.