I am a young, healthy, small person, but I needed to get into better shape, and I despise the gym. I calculated that my wasted various gym memberships would justify switching to a Bellicon, where I can jump to my hearts content, and be creative with my movements, working on all parts of my body with just one machine. It is a great feeling to be sore the next day in my legs and butt, and in my core. I know it is working. I am a singer, so it helps me with my breath, and control. I can challenge myself by trying to sing, and warm up vocally while jumping! (Another reason why I like privacy, that's not something I can do at the gym!). It also boosts my mood, let's face it, it's just fun to jump around! I am also a person who can't stand the cold, and where I live, winter lasts a LONG time. If I can stay in shape during the winter months with my Bellicon, indoors, it is a wonderful option. It is easy on my knees, which can take a beating at the track or the gym. I feel that It helps my joints, actually. Also, I have the largest size of the Bellicon, and I find that to be best for me. I like to really go crazy and get creative with my workout, so with the smaller sizes I fear I would have tumbled off of it by now. That's just me, if you do more gentle workouts, the smaller size should be fine. I definitely recommend the Bellicon!