A dietary supplement for enhancing physical performance of human subjects is disclosed. The supplement in dry, finely-divided form includes as a major ingredient a soy protein isolate containing at least 80% protein on a moisture-free basis with lesser amounts of carbohydrate, free form amino acids, medium chain triglycerides, creatine monohydrate, l-carnitine, grape seed extract, coenzyme Q10, piper nigrum extract, and alpha lipoic acid. In a preferred embodiment, the supplement also includes minor amounts of conjugated linoleic acid and phosphatidylserine/phosphatidylcholine complex.