[Aoife]

Sacrificing weight might injure your pride. Sacrificing your form can injure you.

If you run into problems like Annette it woud be better to do more reps with the lower weight, split your set between the higher weight and the lower weight, find a variation that is more difficult in order to breach that difference, or find a way to add less weight.

In Annette's case, she could have done the 20# for a couple reps then gone back to the 15, found some 17.5 dbs to use (they exist in smaller increments before 20#), added some plate mates to get to 17.5, or added wrist weights to get an additional pound then 2 for an in between amount.

I've had this argument many times with many people, certainly I'm no expert (or "expert"), but I can't see a reason to justify purposefully screwing with your form when all you are doing is some training. If you were in a situation in real life where you had to lift a car off your baby and needed to sacrifice form, sure. Just like you might need to gnaw your arm off to save your life. But is pride in the gym worth the risk of injury?