Plasma volume and ion regulation during exercise after low- and high-carbohydrate diets

This study compared plasma volume (PV) and ion regulation during prolonged exercise in control vs. glycogen-depleted (GD) conditions, with emphasis on the initial minutes of exercise. In two trials separated by 1-2 wk, four adult males cycled at 75% of peak oxygen consumption (VO2) until exhaustion (50 +/- 7 min for GD) or until the GD exhaustion time in the control trial. Blood was sampled from catheters placed in the brachial artery and …