Walking is considered by einstein and pretty much all thinkers to be critical to deep work. It's also covered in Cal Newport's book "deep work" briefly. Which is a short audiobook worth reading.

One such prescription would be to do deep work early in the day then walk after and walk again 2 hours before bed. Another would be split the deep work with a 1 hour walk and do the 2nd walk after the 2nd block.

It may be more fulfilling with lots of interesting ideas rattling around. YMMV