Is it normal to feel like this?

I do that exercise..I dont know what its called but its a pretty well known exercise. It works on your torso and it reduces love handles. Its where you stand in one position and move left to right, using your hip as a pivot. I think its called side-ab crunches. One rep is left to right..and I do 100 reps everyday after my workout. By the end of the exercise I feel like my spine has elevated and become longer..like the disks of my spine have been spaced out lol. Its a hard feeling to describe..it feels like something is pulling you up but your feet are glued to the ground...and you're being stretched like an elastic band. This feeling lasts for maybe 7 minutes and then goes away. I'm a 17 year old male and my height is 5' 6 and I think I'm still growing because my dad is 5' 8. I don't wanna do anything which can stunt my growth...so thats why I'm asking whether this feeling is normal or not.