I had an Ironman mat that was a bit shorter (6.5') but looked the same as the one in this picture. The review by CCody is my experience as well, this mat wont stop heavy rubber off-gassing. This would be bad enough in normal circumstances, but add to it that you are potentially breathing very hard next to the mat (you are exercising) and it is not going to work at all. I went so far as to leave this mat outside for two weeks, but this did no good. The off-gassing continues, I'm sending it back.
Buy Ironman Deluxe Treadmill and Equipment Mat - 3 x 7-Feet, 1/4-Inch Thickness!