I started working out when i was 14 at a gym. I loved it. I took up running in high school and it took me from 200lbs on a 5'8" frame to 150#. I of course grew taller since then, now at 5'10" and 160#. I'm pretty happy with my body.
I found out early on that when I'm working out or running, or any activity like that- it's a time that you really learn a lot about yourself. You learn your strengths and weaknesses. The self-talk starts to come out and you realize if you're really supporting yourself, or if you're your biggest critic. I find it's also, for me, a devotional time.
I ran my first 10k last year. During that time I felt like God was right there with me encouraging me and just helping me shed layers in life and not just physically. Oh- and i'm a crossfit fan. Big time.
Crossfit helped me out of a pretty dark time in my life and now I'm thankful everyday for it.