The purpose of this study is to determine the effects of antibacterial mouthwash on muscle speed and power in healthy young men and women. We have previously demonstrated that drinking beetroot juice, a source of dietary nitrate and therefore nitric oxide, increases muscle function in this population. Antibacterial mouthwash has been shown to interfere with the conversion of dietary nitrate to nitric oxide. We therefore hypothesize that it will diminish nitric oxide bioavailability and inhibit muscle contractility.

Study Visit One:

During an initial visit, subjects will complete the informed consent process, be instructed on the requirements of the study, and practice the exercise protocol (see below).

Study Visit Two:

Subjects will be tested after they have avoided exercise, caffeine, alcohol, chewing gum, and foods high in nitrate (e.g., spinach, beets, collard greens) for at least 24 hours. They will also be asked to not use any mouthwash products during this period. They will then provide provide a saliva sample for subsequent measurement of nitrate and nitrite concentrations and have their breath nitric oxide levels measured using a portable analyzer. The maximal knee extensor speed and power of their knee extensor muscles will then be measured using an isokinetic dynamometer. This machine can control the speed of movement while measuring the maximal force (torque) that a subject can voluntarily produce.

Subjects will then be randomly assigned to receive either an antibacterial mouthwash (Cepacol©, Reckitt Benckiser, Parsippany, NJ) or, as a control solution, an alcohol-free "natural" mouthwash (Tom's of Maine©, Kennebunk, ME). Participants will be asked to rinse their mouth as directed on the product's packaging for 30 s twice per day for 7 (+/-2) days and to record the usage of the mouthwash on a provided form. Subjects will then return for Study Visit 3 (see below). This is considered a single-blind study, which means that the investigators will not know what type of mouthwash a subject is receives.

Study Visit Three:

At the end of the treatment period, subjects will be asked to return to undergo the same procedures as described for Study Visit Two.

Inclusion:

• Men and Women age 18-30 years old
• No current use of mouthwash

Exclusion:

• Men and Women <18 or 30> y of age
• Unable to provide informed consent
• Current users of mouthwash
• Current antibiotic use
• Current smokers
• Currently pregnant or lactating
• Stage II hypertension (resting blood pressure >140/>90)

An answer of yes to any of the seven questions on the first page of the Physical Activity Readiness Questionnaire (PAR-Q) indicating that the subject is not physically ready for exercise without a medical exam. These exclusions include the following:

• If participant's doctor has ever said that he/she has a heart condition and that he/she should only do physical activity recommended by a doctor
• Pain in chest when doing physical activity
• In past month, chest pain when not doing physical activity
• If participant has ever lost balance because of dizziness or has ever lost consciousness
• Bone or joint problem that could be made worse by change in physical activity
• Currently on prescribed drugs for blood pressure or heart condition.
• If the participant knows of any other reason why he/she should not do physical activity.

1 week