Do this static stretching routine at the end of your core workout. Ab, oblique and lower back stretches to increase your flexibility and release all tension. http://www.spotebi.com/workout-routines/core-static-stretching-exercises/
7 Exercises to a Round and Lifted Butt. here’s 7 exercises that will mix your workout up a bit. These exercises target all the muscles in your glutes and hamstrings and will give you a fitter, firmer butt.