Great rap is superhero music: Put it on and you’ll feel like you can break through walls. Along with Apple Music's editors, Apple Fitness+ trainers Bakari, Kim, Anja and Jamie-Ray chose these hip-hop and R&B tunes to guide you through the peaks, valleys, peaks, peaks and more peaks that make high-intensity interval training (HIIT) one of the most demanding—but rewarding—ways to work out. Because if you wanted to take it easy, you’d take a nap.