Endurance Trial: Ketone and Carbohydrate Supplementation

This randomized, double-blind, crossover study investigates the effects of exogenous ketone supplementation on physical and cognitive performance in amateur endurance athletes during exhaustive exercise. Participants will complete three 3-hour cycling sessions under different nutritional conditions: carbohydrate alone (CHO), carbohydrate plus ketone (CHO-KET), and placebo (PLA). The study will assess cognitive function through validated computerized tests, physical performance via distance covered, and metabolic responses through blood biomarkers. Additionally, peripheral blood mononuclear cells (PBMCs) will be collected and cultured with LPS or not. Other PBMCs co-cultured with neuronal cells (SH-SY5Y) to investigate neuro-immune interactions. The primary hypothesis is that ketone supplementation will preserve cognitive function and enhance physical performance during prolonged exhaustive exercise compared to carbohydrate supplementation alone, potentially through anti-inflammatory mechanisms and alternative energy substrate provision.

Inclusion Criteria: * Amateur male cyclists; * At least 2 years of cycling experience; * At least 5 hours of endurance cycling training per week; * VO2max of at least 50 mL/kg/min. Exclusion Criteria: * Confirmed diagnosis of COVID-19 by PCR or rapid antigen test within the last 12 months; * Symptoms compatible with COVID-19 within the last six months; * Smokers; * Alcoholics; * Presence of neurological, immune, or muscular diseases; * Use of psychoactive medications in the last year; * Use of any acute medication prior three days each visit that possible could affect the experiment such as stool-altering medications and non-steroidal anti-inflammatory drugs; * Confirmed gastrointestinal infections, diseases, or disorders (e.g., coeliac disease, inflammatory bowel disease, irritable bowel syndrome, diverticular disease, gastroesophageal reflux disease); * Medical history of gastrointestinal surgery, or any other self-reported gastrointestinal issues; * Within the previous three months, if they had consumed substances that could affect gastrointestinal integrity or followed gastrointestinal-targeted dietary regimes; * Participants with any food allergy should be excluded of this study.