WHEY PROTEIN: A by-product of cheese production, whey protein can help you retain muscle when used immediately after strenuous training. Look for whey supplements marked undenatured, which provide the raw materials for cells to build glutathione, a powerful antioxidant.
Serving Suggestions: Mix a scoop of unsweetened whey—we like Natural Factor or Bluebonnet—into yogurt, oats, or shakes.