Exactly the opposite for me, I tried to add 10 minutes of walking to my workday (midday) and I only lasted a month. I found it so distracting; I lose so much productivity, would be unable to concentrate for at least an hour afterwards, and sometimes for practically the rest of the workday.
I absolutely do think exercise can help with work, in general, just not immediately after for me. A walk after work is much better, to prepare for the next day.
Try pomodoro instead. It's 25/5 work/break. I started out with 60/15, then 45/15, then 25/5 and found out they were right. These breaks, for me, are just walking elsewhere to do a household task and then coming back. For most, it's likely all you need.
Meanwhile, another commenter who walks around Manhattan says that "distraction is the catalyst", and in the article they have participants walking on a treadmill in front of a blank wall, and others walking "outdoors along a predetermined path" (but where?) with the same results. Furthermore, what they measure and call creativity is thinking of uses for a button or thinking of the word "cheese".
Are you carrying a lot of stress when you were walking 10 min mid-day? I think the wandering, creative mind is the goal and walking often facilitates that, but if some stronger force is keeping you away then it may not work.