Originally Posted by
zarbog
If you are really concerned, check in with your doctor. If you are just unfit but healthy otherwise, start pushing yourself. It's not easy but it will pay off eventually.
+1
I'm just chiming in to try and give you a bit of encouragement. Sometimes pushing yourself can be the biggest obstacle. If you've been sedentary for most of your life you're also going to be dealing with lifestyle changes that are new to your brain and body. Sometimes the next hill may seem impossible, so just push yourself and see how far you can get up it. There's no rule saying you have to make it all the way to the top on the first try.