I have noticed that every time i start to lean out my arms get small, they felt small today. I have days where they look nice a veiny and pumped and some days where they look soft. Im sure thats due to my diet but my real question is...is there any tricks to keep my arms from getting smaller? I understand that im loosing bf and everything gets smaller and tighter but my uper body doesnt seem to shrik that much just my arms. My stats are:

26 yrs
205 lbs
10-12% bf
5'10"