What just happened???

I had to write about this very briefly... Yesterday I took my regular Attack class at the Chandler club at 4:20. Mondays are the one day a week I participate, so I dedicate myself to do all high that day. I've been doing all high on my appointed days for the past 2 months or so, and it's made a huge difference on my fitness levels.

So I go to my class, and start going. I don't know what happened... maybe it was just an off day! But I was dying during track 4!!! I had to drop to low for most of the track, and didn't recover until 6. I then pushed myself hard during the 2nd cardio block (I kinda had to... I shadowed track 8 and taught track 9, both of which were unexpected) but man, I only had about half the energy I normally do!

Maybe I wasn't getting much sleep, maybe I ate the wrong kind of food for fuel... but it was like none of the past 2 months had happened! Does anyone else have a problem with this? Was it just an off day or should I worry?