Effective Home Ab Workouts?

toabetterlifestyle

Okay so I'm going to start to add a lot of strength training into my routine. One thing I'm going to be lacking is ab routines, because there's like, 2 machines at the gym for your abs and thats it. So what are some good at home or even at the gym exercises for my abs/obliques and back/shoulders? Any suggestions would help tons! Thanks!