Cathe's Burn Sets Round 2: I can't smell my own fire

In order to recover from my 18-mile run I did yesterday (my quads still aren't speaking to me), I decided to fill this cross-training day with the wonderful world of weight work.  Specifically, I did Cathe's Burn Sets again from her new XTrain series.

This is a solid workout, and I actually heavied up all my weights this time.  In fact, at some points I was using heavier weights than Cathe.  But not as heavy as I should have to feel the burn.  I know I should have looked like this during some point in the workout:

photo credit: pasukaru76 via photopin cc

But instead I felt more like this:

photo credit: slworking2 via photopin cc

In this workout you do three exercises per muscle group (chest, shoulders, back, biceps, triceps), and then you do what Cathe calls a burn set, which is an exercise designed to really make those muscle fibers burn baby burn.  They usually involved resistance tubing and a firewalker band, which required me to go get even more equipment (I hate workouts that involve a lot of equipment).

Again, I wasn't feeling it.  I mean I was feeling it.  But I wasn't FEELING it.  There was no spontaneous combustion of my muscles going on.  At all.  Maybe a sputtering of a flame.  Like a sparkler on the 4th of July.

Hmmmm.

I did heavy up on all my weights, but the heaviest weight I own is a set of 20 pound dumbbells.  I could have picked up my 40 pound dogs, but I am not interested in getting bitten.  I mean, I was using those 20s on exercises I never have before (biceps and shoulders, mainly), and was whomping out tricep extensions with my 12s when I normally use 8s, but those burn sets didn't burn.

Maybe my muscles are made of flame retardant materials.  Or I just need heavier weights.