Working out too Little?

Hi guys.
I used to train 6 days a week (overtraining) and I have switched to 4 days a week for about 3 weeks. I have lost some noticable size in my arms mostly because I used to train them 2 times per week. My weight is a little less (1-2 pounds)

Day1: Chest back
Day2: Bi, tri
Day4: off
Day5: legs shoulders abs
day6: Chest and Back
OFF

What do you guys think? I been training for a solid couple of years and diet looks good also thanks to the guys on this forum.

What do you guys recommend, 4 days, 5 days or 6?

well if you liked the 6 week routine and saw good results with it go back to that. then every like 6-8 weeks just take a deload week to give your body a rest and then come back hard the week after that.