If you haven't heard of TRX, it's basically a set of fancy cam straps where you use your own body weight for resistance. Go here for more info. It sounds simple, but it most definitely is not. I remember prior to my first TRX workout (despite hearing how dang hard it is!), I showered and did my hair and makeup. Because, really it's just a set of straps, it can't possibly be that difficult. I seriously didn't think I would work up a sweat. 40 minutes later I was using every ounce of will power to keep from puking all over Jenn's driveway.
I owe a special shout-out for Jenn, who has been working with me a couple of times a week. She's been awesome, and I can't think of a better person to routinely embarrass myself in front of. Thanks, girlfriend!