Intermittent Running and Cognitive Performance after Ketone Ester Ingestion

In a double-blind, randomized crossover design, 11 male team sport athletes performed the Loughborough Intermittent Shuttle Test with a 6.4 percent carbohydrate-electrolyte solution alone or with 750 mg/kg of a ketone ester. Ketone ester raised plasma beta-hydroxybutyrate to about 1.5 to 2.6 mM and lowered plasma glucose and lactate. Heart rate, perceived exertion and 15 m sprint times did not differ, and run time to exhaustion was not significantly different (268 s with placebo versus 229 s with ketone ester, P = 0.126). Incorrect responses in a multitasking test rose from before to after exercise with placebo (1.8) but not with ketone ester (0.0; P = 0.017).