I just received it two days ago and have only used it once so far but what I've experienced so far, but will use this as part of my weekly exercise regimen.
I love this device bought one for my mom, and 3 of my friends have bought after my reccomendation, unfortunately with 8 months it started working for no reason, I didnt move it, it has been in the same spot of my room no change or incident and it stopped working. Luckily it has a lifetime warranty, hope the process goes well.