Fuel for optimum performance. With other natural flavor. 1 Before; 2 During. PowerBar is backed by Nestle's worldwide leadership in nutritional science. Learn about the science behind PowerBar. Good to know: did you know the food you eat before and during intense training can optimize your performance? Good food, good life. Good to remember: this PowerBar Performance Energy Bar has a dual source energy blend to deliver maximum fuel to muscles. See PowerBar.com for the science. You're stronger than you think. www.PowerBar.com.