New! PowerBar® Fuel System Fueling Victories Every Day in Training & Competition. Helps Build Lean Muscle. With Other Natural Flavor You train hard, make it count. PowerBar ProteinPlus® bar has a TriSource™ protein blend to help build lean muscle and provides sustained energy for active people. Take PowerBar ProteinPlus® bars after training or competition where protein intake has been shown to help promote muscle recovery. This bar contains 20 g of TriSource™ protein, a proprietary blend of whey, soy and casein proteins that provides muscle-building amino acids.