Originally posted by defdaz
The reason (probably!) why you weren't getting a great workout was that it was your lower back... was giving out first
Yup, that was it.

Originally posted by defdaz
Can your muscles (quads in this case) identify what exercise you are doing? Do you think they care how many plates you've got on that bar? Do you think that's air, that you are breathing? Er...

No, seriously, all your muscle knows is how hard it has to contract and what the current state of itself is (acidity levels, ATP / creatine / glycogen levels etc.).

It's the effect the training has on your target muscles not the weight that you lift that is important...

Daz
Great advice Daz... thanks.