Keep the Weight Off!

It was in my teenage years (as i recall....it wasn't too long ago) was when i veritably healthy and sporty. I took part in various outdoor activities that i would CURRENTLY find impossible to take part in. The fact of the matter is, i am very determined to get my health and my body back. Do you remember Brunei selling this?(Where can i find it???)
The athletic activities I would take part in a weekly basis (back in my teenage years of course...)

• Basketball
• Softball
• Rugby (touch)
• Driving range
• Equestrianism (wish i could have continued further, but never got past the monthly fee aspect...it was CRAZY!)

I can only recall the main activities...but if i do however eventually remember the others I'll come back an edit this post. (Depending on my mood)
Now to actually have performed all these sporting activities really did wonders for my health and physique. I became more limber, flexible, I could run faster and for a long period of time as well.
I was FIT.How /  when did I develop to someone who cant even keep a steady pace on the treadmill?What has kept me off of physical activities?

• Left Brunei for a while (moved to the States)
• Furthered my education
• Dealing with my studies.
• Dealing with stress and long hours.
• Staying indoors all day.
• Copious amounts of junk food, and ready made meals to microwave.
• Coping with the changing weather.
• Hibernate in the winter
• Dealing with pests. (And i dont mean bugs)

To clear the air and assumptions, I am not overweight...nor would I label myself as 'fat'. Nevertheless i will categorize myself as unfit. I cant run the way i would use to, nor jog. So to deal with this 'speed bump' I want to:

1. Start hiking (weekly)....hiking will be my starting point, who knows where it would lead to?
2. Eat more healthily.