I know plenty of people who have success exercising regularly on their own. I’m just not one of them. I get a more efficient, challenging, and safe workout when someone is there guiding the process. There’s also the benefit of being held accountable for my workouts (or lack thereof) that motivates me to be consistent in my activity levels. It’s also more fun to have workouts that change intensity and type to keep me engaged with the process instead of falling into a workout rut.