Keep your "Core" tight.

Is keeping your "Core" tight the right cue to give? As we see above when I try to keep my "core" tight doing a "Cable Row" it reduces my output and makes the above exercise harder. 

High cable bicep curls.

Ever done high cable bicep curls? Without the support they can feel like a constant balancing act.

Here’s a way to generate far more output on your elbow flexors without having to juggle keeping your arm still.

Q: But isn’t adding support less functional?
A: If increasing output in some muscles cant be considered functional then I dunno what is.