Ketone ester supplementation has become increasingly popular as an athletic supplement. However, the metabolic effects of these supplements on exercise performance are controversial. One potential reason for lack of an ergogenic benefit could be the effects of ketone bodies on other bodily systems, such as the sympathetic nervous system. During exercise and stress the body increases the activity of the sympathetic nervous system. This causes blood vessels to constrict (get smaller) and can increase blood pressure. Studies have shown that ketone bodies can suppress the sympathetic nervous system in mice. Additionally, ketone ester supplementation can reduce blood pressure in healthy adults. In humans, direct measures of sympathetic activity are usually made from sympathetic outflow to muscle, also called muscle sympathetic nerve activity (MSNA). Using a ketone ester supplement, the investigators plan to measure blood pressure and sympathetic outflow to muscle at rest and during handgrip exercise and a mathematical task stress test to investigate the effect of ketones on neuro-cardiovascular stress responses.

Inclusion Criteria:

• 18 to 40 years of age
• Healthy, free of known cardiovascular, metabolic, or musculoskeletal disease

Exclusion Criteria:

• History of smoking (within 3 months), diagnosed cardiovascular or metabolic disease, recent musculoskeletal injury preventing handgrip exercise, prescription of chronic medications other than oral contraceptives.
• Current or recent (within 6 months) use of ketone ester supplementation or participation in a ketogenic diet.
• Inability to abstain from drugs, caffeine, alcohol, or strenuous physical activity prior to the study visit.

Double-blind