There is much to do at an office job, but do you know what does not do much at an office job? Your physical body. An office job is quite sedentary, and while there are ideas to make it more active, it remains one of the larger downsides this kind of job brings along.
Instead of compensating this lack of movement with an entire dedicated activity for exercising, do not forget to look into what you currently do and making that more active. Commuting is a good example, I know good examples like biking (partially) to work. Or walking around during breaks, not just walking to where you need to go but also for other means.