Instruct: Classify Amazon reviews into positive or negative sentiment
Query: re-invent yourself

I'm 56 and needed to prepare with Tony's "Bring It" workout which I loved and have recommended to friends. After 9 weeks of the book I finally jumped in. I bought P90X for my 23 year old son in the Navy and one for myself. We talk at least once a week to compare our pain and progress. I love it. In six weeks of P90X I feel much stronger and have improved dramatically. I stongly recommend it IF you're ready. Do the fit test on line before buying it and if you're not quite there get Tony Horton's book "Bring It" to prepare.