I was listening to a Stephen Covey book while I worked out (because I am a nerd like that) and he was talking about something that we all deal with on a daily basis.
The topic was about the Circle of Concern and the Circle of Influence. Your Circle of Concern is the things you worry about, but have little to no control over (weather, the national debt, terrorism, etc...), while the Circle of Influence are things you can do something about (your health, your kids, personal finances, etc...)
How much time do you waste worrying about things in your Circle of Concern?
How much time do you spend working on the things in your Circle of Influence you can change?
I'm sure you've heard about the Serenity Prayer:
For most people they spend the majority of their time worrying about the things they have no control over. That makes no sense! Worrying about something only makes the problem worse.
If you learn nothing else from me, learn that it is absolutely critical to change your lifestyle. If you haven't made the effort to really get on a good nutrition plan, you will be amazed when you do. When you stay on a regular exercise program it improves your physical, mental, and emotional well being.
Nobody is ever too old, too tired, too this, too that to improve their health. It doesn't take an ounce of talent to get in the greatest shape of your life, you just have to keep showing up. You can radically alter your health and body at any stage of life.
There is so much in life that is out of your control.  Let that go.
Put your focus on what you can influence and dominate that.