As research begins to broaden our understanding of the effects of low carbohydrate, high fat ketogenic diets to different populations, it is crucial to utilize empirical evidence associated with the metabolic and physiological adaptation of chronic implementation. Specific populations are finding that nutritional ketosis may prove advantageous to athletic or cognitive performance. Nutritional ketosis may be identified by an elevated plasma ketone concentration within the blood range > 0.5 to 5 mmol/L that resulted results from a chronic implementation of a ketogenic diet. Recently, science shows that ketones contribute to a vast range of therapeutic and performance benefits associated with nutritional ketosis, as a result, exogenous ketone supplements have become commercially available which have proven to induce acute nutritional ketosis without restriction of carbohydrate intake. However, as research increased for exogenous ketones on a mixed diet populationWe previously showed that a supplement cpontaining ketone salts and caffeine significantly increased performance in a non-ketoadapted population. , To date, there are no reports of whether ketone supplements have an ergogenic effect research has not shown what enhanced benefits may come from exogenous ketones in an already keto-adapted population. The primary purpose of this study was to replicate a previous study with exogenous ketones on a non-keto-adapted group of participants with a completely regulated keto-adapted groupdetermine the performance and metabolic effects of a supplement containing ketone salts and caffeine in a group of people habituated to a ketogenic diet. Twelve habitually ketogenic, recreationally trained individuals (3 female, 9 male: mean + SD age, 36.1 + 7.5 years; weight, 82.2 + 7.1 kilograms; height, 177.7 + 8.5 cm; VO2max 40.3 + 10.5 ml/kg/min). participated in two experimental sessions in a randomized and balanced order. Subjects consumed either a ketone-salt/caffeine supplement containing 7.212g BHB and 96.2g caffeine or water (control condition) 15 min prior to performing a staged cycle ergometer time to exhaustion test followed immediately by a 30 sec Wingate test. Symbol digit modality tests were administered at baseline, immediately post-exercise and 30-/60-min post-exercise. Blood ketone concentrations were significantly increased peaking 15 min after ingestion by more than 2-fold and staying elevated throughout 60 min recovery. Compared to the water trial, ingestion of the ketone-/caffeine supplement significantly increased time to exhaustion (9.8%; P = 0.003) and increased peak VO2 during exercise (12%; P = 0.03). There were no significant differences between conditions in peak power output, average power output, cognitive performances, or blood glucose responses. These results indicate that ingestion of a moderate dose of ketone salts and caffeine prior to exercise significantly increases the magnitude of ketosis and improves high-intensity exercise performance in keto-adapted individuals.