I purchased an expensive ems unit from a medical wholesaler about 2 years ago, but I stopped using it 5 months later when I had the thought that putting electrodes on my body could be fucking me up, and could lead to cancer. I only ever used it on my abs, biceps, triceps, and chest, as the back,shoulder, penis(ha ha)and leg muscles are too complex too be messing with. I didn't notice any gains in arm strength, although the muscles that I did use it on seemed harder. I can also do heavier ab excercises than anyone I know, not sure if this is due to the ems, cause I was also using gravity boots at the time. I experimented on my friends with it and I noticed that the more they could lift, the more voltage they could handle. The ems machine didn't give me a eight pack, I still had a thin layer of fat covering my abs (I have always been thin) but they were harder. Have any of you ever used EMS, or TENS (i havent ever used TENS)? What are your thoughts?