It's not that it's a bad app, it's a fantastic app, one of the best of it's kind. But if you look closely at the screenshot I leave you after these words you will understand exactly why the Jawbone up bracelet discourages exercise.
Because it is basically telling you that you have burned more calories while doing nothing then the amount of calories you've burnt while actually exercising. It was one of the most striking things that caught my attention when I started using the bracelet and app. After walking 20 miles in a day seeing that you've spent more calories when you where sleeping than when you actually made some time to exercise is quite a disappointment. It completely discourages you from even wanting to exercise if you're gonna end up burning pretty much the same amount of calories while slacking around or even more.
Point is, it shocked me. That said it's a pretty awesome device if you like to lead a healthy and "sporty" lifestyle, and a total must have if you're a regular jogger. Not sure it's for me, though I do very much appreciate all it's sleep related stats and functions.