2018/11/01 by MARK EVANS, BRENDAN EGAN · 1 citation
paper · doi:10.1249/mss.0000000000001700
ABSTRACT Purpose Ingestion of exogenous ketones alters the metabolic response to exercise and may improve exercise performance, but it has not been explored in variable-intensity team sport activity, or for effects on cognitive function. Methods On two occasions in a double-blind, randomized crossover design, 11 male team sport athletes performed the Loughborough Intermittent Shuttle Test (part A, 5 × 15-min intermittent running; part B, shuttle run to exhaustion), with a cognitive test battery before and after. A 6.4% carbohydrate–electrolyte solution was consumed before and during exercise either alone (PLA) or with 750 mg·kg −1 of a ketone ester (KE) supplement. Heart rate, RPE, and 15-m sprint times were recorded throughout, and serial venous blood samples were assayed for plasma glucose, lactate, and β-hydroxybutyrate. Results KE resulted in plasma β-hydroxybutyrate concentrations of ~1.5 to 2.6 mM during exercise ( P P = 0.126, d = 0.45) between PLA (mean = 268 s, 95% confidence interval [CI] = 199–336 s) and KE (mean = 229 s, 95% CI = 178–280 s). Incorrect responses in a multitasking test increased from pre- to postexercise in PLA (mean = 1.8, 95% CI = −0.6 to 4.1) but not in KE (mean = 0.0, 95% CI = −1.8 to 1.8) ( P = 0.017, d = 0.70). Conclusion Compared with carbohydrate alone, coingestion of a KE by team sport athletes attenuated the rise in plasma lactate concentrations but did not improve shuttle run time to exhaustion or 15-m sprint times during intermittent running. An attenuation of the decline in executive function after exhausting exercise suggests a cognitive benefit after KE ingestion.