I am full on obsessed with CXWorx, Les Mills' core training program. A quick 30 minute class that hones in on the torso and sling muscles that connect your upper body to your lower body. It’s ideal for tightening your tummy and butt, while also improving functional strength and assisting in injury prevention.
I started going because Q over at LAQuillen.com encouraged me to go to one of her classes. The class is broken into a few tracks, I would like to tell you how many, but have no idea because I am too plum tired to figure it out during class. (Q tell 'em in the comments)
My absolute FAVORITE move is when we hold a plank and then move our hand out at a diagonal and while doing the same with the opposite foot. It is intense!
I also really like the standing tube resistant exercises that work your hips--I like anything that works my hips.
The music is fabulous and honestly the best part, is that it is the same class no matter what day and time. So I try to make it twice a week and it doesn't have to be the same two classes each week, which is really helpful with my schedule.
If you have a gym near you that does the Les Mills exercise, I would HIGHLY encourage you to check this one out.