Even if you hate the gym or even the thought of any structured program you can still exercise. If it's too cold out or conditions are too bad to go outside, do simple stretches. If you want to go further than that there are several simple exercises that can be done inside the privacy of your home.

I understand lack of motivation to even get started. Although I've been physically active most of my adult life, there are times when the motivation is just not there. I have episodes of depression. I know that doing any kind of exercise will improve my flow of endorphins but sometimes that knowledge is not enough to motivate. That is when I do very simple and gentle stretches. Even if I only do two or one per day it is a small step that helps to increase motivation.