Diario de RoseFlorida, 14 sep. 15

I do crunches to help tighten my upper and lower stomach! There are regular crunches, reverse, bicycle, right arm to left knee, left elbow to right knee and double crunches (regular and reverse at the same time). I started with 25 and added 5 every other day. I only did them every other day. I do 100 3 times a week and have lost 2 inches in my waist and hips! :-D  

They say planks will really do it. 

There are oodles of core exercises on youtube, but choose beginner ones and if they don't seem like the instructor knows what they are doing - find another. You could also go to a local fitness center - join a class or at least get some ideas from a personal trainer. Planks, starting on your knees and hands is a great starting point. You can also use the counter edge and plank there, bracing your core, like someone is going to sucker punch you, and hold while breathing as long as you can. Repeat at least 3 times. Try it every other day for a week and see if you are holding it longer the next week. It doesn't take long to get your core strengthened - we use it for everything! Good luck!