Use a headset, a radiotelephone or a long telephone cord — anything that will allow you to move freely while you are talking on the phone. Even if you just stand up, you will still involuntarily shift, which is already a small warm-up.
Immediately after eating, the concentration of fats in your blood is maximum. Taking a walk, you will increase the production of lipoprotein lipase, an enzyme that stimulates metabolism and promotes faster fat burning.
At a picnic or during a regular outing to the park, try to sit down less. Walking with someone, do not rush to the bench. It will be hard for you to force yourself to stand, but still try. Soon you will get used to it, and you will feel much more cheerful and ready for active outdoor games. After all, if you are sitting, you still need to get up, and this can sometimes be difficult!
Instead of calling the next office or writing letters, get to your colleague. Need to discuss a work issue? Invite him to walk at least along the corridor.
It may be objected that such behavior at work contradicts the laws of productivity, but very soon you will get used to solving things quickly without dragging out the conversation, and a few ascents of the stairs will definitely benefit your health. After all, there is a proverb "Legs are wheels of thoughts". Perhaps it is on the move that you will come up with a brilliant idea.
It is not necessary to have a giant workplace for this. Especially if you work on a laptop. Adjust the bedside table near the table for standing work (you can put something on it to increase the height).
Try to change the chairs from time to time, or at least the position in which you are sitting. For example, it is sometimes useful to sit cross-legged in Turkish. Rotate in your chair to reach your phone or papers.
In general, use every opportunity to move at least a little, and soon you will notice that you began to feel more cheerful and stopped falling asleep at work!