Flavonoid Supplement: Supplement and placebo capsules will be prepared by Reoxcyn Innovation Group LLC (Salt Lake City, UT). (SEE supplementation information in attached file). Ingredients will be the same as tested in the community trial: vitamin C (as ascorbyl palmitate) (Green Wave Ingredients, La Mirada, CA), wild bilberry fruit extract (25% total anthocyanins) (FutureCeuticals, Momence, IL), green tea leaf extract (50% EGCG) (Watson Industries, Inc., Pomona, CA), quercetin aglycone (Novel Ingredients, East Hanover, NJ), caffeine (Creative Compounds, Scott City, MO), and omega 3 fatty acids (Novotech Nutraceuticals, Ventura, CA). Capsule fill ingredients and excipients include Nu-Flow 70R (from rice hulls), tapioca from cassava root, natural bamboo silica, marshmallow root. Placebo capsules will contain only the fill ingredients and excipients (without the active ingredients). The daily serving for the walkers will be 2 flavonoid or 2 placebo capsules. Two flavonoid capsules provides 329 mg flavonoids (American adult average, depending on the study, is 240 mg per day). The daily serving for the runners will be 4 flavonoid capsules (658 mg flavonoids). Participants will be given a 2-week supply of the either the flavonoid or placebo capsules, with instructions on how to consume daily in split doses (1 with breakfast and 1 with lunch, or double that amount for the runners). Study participants will be allowed to add one extra capsule per day to increase consumption if one or two days of taking the supplement are missed. Study participants will ingest 2 capsules (4 for the runners) just after providing the blood sample during the walk/rest (or run) lab session.