I swear by resistance bands, really I do. They are great for toning up. Make sure you start out with one that is not too stiff though, you don't want to hurt yourself. After you've worked with the beginner one, then switch to a moderate one. As for walking, if you are walking about 4mph, you will walk 1 mile in 15 minutes. So depending on what you're looking to get out of the walk, it all depends. I walk 4mph for 45 minutes, which is about 3 miles. Sometimes I do more, sometimes less. Hope this helped and good luck!