This article is going to show how u can do weight watchers for free, but first off, lets see why weight watchers is so successful. The 4 pillars of success; Food, exercise, behavior & support.
1 Hip muscles. Lunges work all of the gluteal muscles in the hips, primarily the gluteus maximus that is used to extend your hips. Taking large steps during a lunge can further engage this muscle. The gluteus minimus and gluteus medius are also used to stabilize your body throughout the lunge.  Thigh muscles.
Both dumbbell lunges and leg extensions focus on working your quadriceps. However, if you opt for one of the dumbbell lunge alternatives to the basic lunge, you relegate your quads to synergists and make your glutes the focus of the exercise.