Instruct: Classify a review into positive or negative sentiment.
Query: A little weird but effective

The cover of this workout is a bit misleading as there is no use of any exercise balls in this video. None the less, it is a good back workout and my lower back actually feels better when I run now as I have been doing this workout 2 times per week. Relaxing music, but the naration is a little off from the instructor (the original is in german). It is a good back workout - this is not a calorie burner type workout - very relaxing with some challenging moves, but again, I think , effective.