Exogenous ketosis suppresses diuresis and atrial natriuretic peptide during exercise

In a double-blind crossover design, 11 well-trained male cyclists completed a simulated race of 3 hours of intermittent cycling and a 15-minute time trial at 28 degrees C, receiving either a control drink or the ketone ester (R)-3-hydroxybutyl (R)-3-hydroxybutyrate, which raised blood beta-hydroxybutyrate to about 2 to 4 mM. Urine output during the 3-hour bout was about 20 percent lower with ketone ester (1,172 mL vs 1,431 mL, p < 0.05). N-terminal proatrial natriuretic peptide was about 20 percent lower, plasma noradrenaline was raised, and time trial performance was similar between conditions.