If you’re not a visual person—or if you just can’t figure out a good setup angle for your laptop screen—Aaptiv is perfect: It’s audio-only, which means all you need is the app and some headphones to get going. It’s sort of choose-your-own-adventure; it can function as a training companion on a run or at the gym or as a class in your living room. There are thousands of options, so it’s just a matter of filtering for skill level, workout style, and duration.