Rest

I took a week off gym, let my body rest.
Feeling so much better now.
Just did a Full Body routine today to mark the end of the 1 week rest, I think it's becoming a pattern for me, after 8-12weeks of working out my body will start to plateau and tire out.

I guess the take away from this is to remember that rest is important. Your muscles and body don't grow during the workouts, it's only after that when you are resting that your body repairs itself and you start growing.