I tried this out on me and my son I left it on for 30 min working my way up to a pretty good pulse. It does get uncomfortable if you go to the higher settings but my top abs were sore after so it must have been doing what it was meant for. I was skeptical at first but once I started going up to the higher pulse I could feel my muscles tense. It’s a weird sensation like a whole bunch of tiny shocks. I am excited to see if I get the results I’m hoping for