I think just about everyone has those days. Are you truly exhausted or are you just sick of working out? For me, if I ignore the days when I'm truly drained of energy, it leaves me vulnerable with my immune system and I end up getting sick. If I'm just bored and fed up with working out, I'll sometimes take a day off, but usually, I'll put my workout clothes on and lie to myself. Yep, I do. I tell myself that I"ll only do a quick 10 minutes, just to break a sweat, but it usually turns into a full workout and I end up feeling very proud of myself afterwards.
First goal: under 180:
Second goal: 175 or below:
Third goal: 168 (no longer overweight):
Fourth goal: 160 or below:
Final goal: 145-155 (not sure if this will ever happen):