FB 30 Round 3 Upper Body + Abs

My day today =D

I'm currently following FB30 since I have barely any time to spare and am happy when I can do even 30mins a day 5x a week. Getting up at 5am also makes me really tired since I much prefer to sleep at least until 7-ish. :D But no other choice currently!

On Friday evenings, I go to circuit training at my local martial arts gym, which is my reward after the work week. This is usually followed by complete rest or only light stretching on Saturdays, but today there was ample time and energy; plus, yesterday's training was heavy mostly on legs. Logical choice? Upper body workout! I added the abs portion since I felt quite daring xD

Abs first since I want to focus on a strong core atm. By the time everything was done, they and my arms were toast. My problem with arms/ shoulders is that I feel I can't do much during the workout (especially with bodyweight push-ups), but then afterwards the muscles aren't particularly tired, either. Do you guys experience the same? What do you suggest for it - maybe lift heavier, add more (short) upper body workouts onto the regular ones? Maybe add some push-ups as a burnout round regularly after the workout of the day?