Bike fit / correct riding position

I went to a bike fitter complaining of not being able to drive any reasonable amount of power to the pedals because it felt like I was riding while crouched down, even though the seat was in the right place and the cranks were the right length, yadda yadda. He moved my stem down by 5mm and that was all it took to allow my body to generate a normal amount of force. It's bizarre how little it takes.

The free ride function on trainer road is good for this. Set the bike up on the turbo, and play with your position while recording your power output.

Obviously you'll only be looking at short term power. But I find doing this followed by a long ride to dial things back towards an endurance fit pretty usefull.

An interesting (probably not) problem I have. Is that after playing as a rugby hooker for far too many years. I seem to have an overly aggressive position, and I like to use my quads for power efforts. But I have near zero endurance while using them.