We are born moving and have instincts to move that are rhythmic. At certain times it feels better for us to move than others. Like at times it feels better and easier to get to sleep than others.
This article, "Lack of Exercise can disrupt the body's rhythms" is talking about exercise helping us to know optimal times to move. It feels like its conflating exercise with movement, which sometimes happens. They aren't the same. The peaks of your natural instinct toward movement is something you should be able to pick up on at any state. If anything, I'd say exercise isn't a good way to achieve this for most people. Especially if you aren't in to it.
It's a bit like demand feeding/normal eating/intuitive eating. You have to clear psychological obstacles out of your mind-like identifying your body as inherently incompetent or yourself as forever physically incapable. Adopt a new more neutral open-minded stance, if positivity is too much of stretch.
Put your mind on alert for optimal times to feel the urge move at its most strongest, then above all, respond to those feelings/urges, freely. Act on them, no matter how short in duration-seconds even!
Follow through with that impulse as long as it feels good to you, stop promptly when it ceases to- at least at first, until you get into the swing of things, later you'll gain more flexibility.
With consistent practice and patience these urges should become stronger and more distinct, longer lasting and more satisfying to engage with.
The key is learning to perceive and go with rise in your instincts to move, synchronize impulse with a positive response. Avoid overburdening them with excess desire, guilt or shame about seeing yourself as inactive, or needing to make up for lost time.
Now's the time to learn patience and love for yourself. Go at your own pace.
You can do this outside the movement you need to make to go about your normal affairs. It will feed into that at some point.
Make a point of shifting your consciousness away from any negative or forcing to a more coaxing wait and see what you can do, type stance.
If at first you can't feel any sense of an urge to move, then try for least disinclined/most easeful of all. And take it from there.......