Exercise is absolutely important! That said, it does not offset all the negative health consequences that develop over time from prolonged bouts of sitting all day.
Your body was designed to move and many of its internal processes only function optimally as a reaction to physical movement.
Here is what you can do:
1) Turn off your video camera on the next zoom call and move around and stretch.
2) Stand during your next zoom call.
3) Incorporate movement or stretching breaks every hour while working. If you work at home - perhaps do some chores. If you are at a place of work - get up and go for a quick stroll around the workplace
Just remember the saying "what moves lives, what doesn't dies".