Research Design: Study participants (N=85) will be entered into the study and randomized to the flavonoid or placebo supplement groups for 2 weeks, with these two independent groups run in parallel (with N=80 anticipated to successfully complete all study phases). Supplements will be administered in a double-blinded manner in capsule form. Study participants will report to the research facility for baseline testing and orientation, and then pre-study and after 2-weeks supplementation, and then again 24 hour later. Four blood samples will be collected as shown in the Figure (pre- and post-supplementation, post-exercise/rest, and 24-hour post-exercise/rest). When reporting to the lab after 2-weeks supplementation, study participants will be randomized to either sit or walk briskly on treadmills for 45 minutes. A comparator group of 20 runners ingesting the flavonoid supplement and running 2.5 h in the lab will be included to allow a comparison between moderate and intense exertion (and to provide pilot data for a future study). Baseline Testing: One to two weeks before the start of the study, study participants (walkers and runner) will be given an orientation to the study and then provide voluntary consent. Instructions will be given for recording all food and beverage intake in 3-day food logs (Thursday, Friday, and Saturday prior to starting supplementation). Demographic and training histories will be acquired with questionnaires. Height, body weight, and percent body fat (seca Medical Body Composition Analyzer 514 bioelectrical impedance scale, Hanover, MD) will be measured. VO2max will be assessed using the Bruce's treadmill protocol, with oxygen consumption and ventilation continuously monitored using the Cosmed CPET metabolic system.