This DVD is for the serious minded exerciser and not a beginner. I was looking for a DVD to replace another DVD and this one more than fit the bill. The 20 minute work-out is ok for a quick workout. The hour long workout is amazing. By the end of the workout my arm muscles were jello. I could barely get through this workout but I did and I felt it the same day and I am an intermediate to advanced exerciser. I love it. If you want to see quick results, get this DVD. Bob is tough and makes Jillian Michaels look like a Sunday school teacher.