Exogenous Ketosis Impairs 30-min Time-Trial Performance Independent of Bicarbonate Supplementation

ola Kala shared this article with you from Inoreader Exogenous Ketosis Impairs 30-min Time-Trial Performance Independent of Bicarbonate Supplementation Μέσω Medicine & Science in Sports & Exercise - Published Ahead-of-Print Purpose We recently demonstrated that co-ingestion of NaHCO3 to counteract ketoacidosis resulting from oral ketone ester (KE) intake improves mean power output during a 15-min TT at the end of a 3h cycling race by ~5%. This ergogenic effect occurred at a time when blood ketone levels were low as ketosis was only induced during the initial ~2h of the race. Therefore, in the current study we investigated whether performance also increases if blood ketone levels are increased in the absence of ketoacidosis during high-intensity exercise. Methods In a double-blind crossover design, fourteen well-trained male cyclists completed a 30-min time-trial (TT30') followed by an all-out sprint at 175% of lactate threshold (SPRINT). Subjects were randomized to receive either i) 50g ketone ester (KE), ii) 180 mg⋅kg-1 body weight NaHCO3 (BIC), iii) KE+BIC or iv) a control drink (CON). Results KE ingestion increased blood D-ß-hydroxybutyrate to ~3-4 mM during TT30' and SPRINT (p0.05 vs. CON). Mean power output during TT30' was similar between CON and BIC at 281W, but was 1.5% lower in the KE conditions (main effect of KE: p=0.03). Time-to-exhaustion in SPRINT was ~64s in CON and KE, and increased by ~8% in the BIC conditions (main effect of BIC: p View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.