Diet can alter blood ketone levels and this in turn may affect exercise capacity. This study will determine if the acute ingestion of a ketone supplement alters cycling time trial performance. Participants will perform two trials in a randomized order. Each trial will involve a 20-minute bout of cycling on a stationary ergometer. Participants will ingest either a ketone supplement or a taste-matched placebo drink prior to exercise. Blood samples will be obtained to assess selected metabolic responses. This study will provide information regarding the effect of ketone supplementation on exercise responses.

This study will determine if the acute ingestion of a ketone supplement alters cycling time trial performance. Trained participants with competitive cycling experience will be recruited. Exercise will involve a 20-minute bout of cycling on a stationary ergometer with the goal of producing the highest power output possible. Participants will ingest either a ketone supplement or a taste-matched placebo drink prior to exercise using a randomized, double-blind crossover design. Diet prior to exercise will be standardized between trials for a given participant. Blood samples will be obtained to assess selected metabolic responses. This study will provide information regarding the effect of ketone supplementation on exercise responses.

Inclusion Criteria:

• Habitually ingesting >50 g of dietary carbohydrate daily i.e. not following a ketogenic diet.
• Regularly performing cycling exercise at least 3 days per week and for a total of ≥5 hours per week.
• Having an estimated peak oxygen uptake of ≥55 ml/kg/min for males and ≥48 ml/kg/min for females based on the online fitness calculator available at: www.worldfitnesslevel.org.
• Having competitive cycling experience.

Exclusion Criteria:

- Experiencing a condition that might preclude safe participation in physical activity and exercise, as determined by answering "Yes" to any question on Page 1 of the Canadian Society for Exercise Physiology Get Active Questionnaire.