Little or no activity combine to form a vicious cycle that works something like this:
You find yourself not feeling good for some reason (or for no particular reason), so you don't feel up to doing pretty much anything at all.
So you mope around.
It's gotten so bad that activities you used to do and enjoy don't even interest you anymore. You end up watching a lot of TV.
Then, to make matters worse, as you continue to sit around the house, you start to eat more. And your choices of foods has gone out the window - you're eating more junk.
Instead of taking (and making) the time to prepare your food, you grab some convenience food from the freezer and throw it in the microwave.
Your body becomes sluggish and your thoughts self-defeating.
During this period (which can last from a few days to several months, even YEARS), your body's needs are grossly exceeded by what you take in; you're putting more fuel into your body than it can use.
Result: excess weight and fat.
And the more fat you lay down, the more sedentary you become, and the lazier you get. Whatever little bit of energy you had before this happened is now gone. Now you're trapped by escalating fatigue.
This vicious cycle keeps your metabolism at a snail's pace. Low metabolism, low energy. Low everything.
Now, if you're caught in this black hole of inactivity and fatigue, you can dig your way out. YOU ARE NOT A PRISONER OF INACTIVITY AND LACK OF ENERGY.
Just start an exercise program. Move that body. You're not going to be given energy on a silver platter, IF YOU WANT ENERGY, YOU'VE GOT TO DO SOMETHING TO PRODUCE IT. And that means getting off your butt.
Start slowly and build yourself up gradually, over the course of a few weeks. What you're doing here is forcing your body to increase its energy expenditure. As you start to burn some fat and tighten some muscle, your mood WILL improve. And that will help motivate you to keep at it.
Exercise increases the level of positive, "feel-good" hormones, known as endorphins. That helps you to sustain a good feeling throughout the day. Feeling good improves perceptions and personality, which allows you to make better and more positive choices. Studies show time and again that people who work out are more optimistic, and better able to handle stress.
I've had many people tell me, "Oh, I KNOW when I exercise I feel great afterwards. I loved that feeling! Well, that is, when I DID exercise."
THEN WHY AREN'T YOU STILL DOING IT?