Instruct: Classify the given Amazon review into its appropriate rating category
Query: Not impressed.

Not impressed. I'm out of shape and I know it. Been using this belt for about a week. Had to turn it up to 50 to feel any muscle contractions at all. Turned it up to 100 for an hour yesterday, and I don't feel anything in my abs. My muscles should be sore. 20 crunches would do more.