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/
4 Cool-Down Stretches For After Your Workout That Feel Ridiculously Good
For best results, cool-down stretches should be passive, so you’ll hold them for a while (as opposed to dynamic stretches before a workout, which you shouldn’t hold for long). As a rule of thumb, she aim for six to eight deep breaths.
Work on your abs and obliques with these core exercises for women. A 30 minute waist cinching workout to activate your obliques and define your waistline! http://www.spotebi.com/workout-routines/core-exercises-for-women-abs-obliques-workout/