Originally Posted by RadSwim
If you can ice skate, you will know you have achieved core power when you feel a similar side-to-side swaying motion that you feel when ice skating.
This is exactly the feeling I get when I swim my fastest and easiest. On average I take 14 strokes for 25 yards. Focusing on a skate-and-glide (trying to emulate the lazy roll of olympic distance skaters) I can usually drop 2 strokes.
Then I start over-thinking my stroke pattern and focusing on too many details at once and I'm right back at 14. Don't underestimate the effect of simple, positive thinking, and pure joy. When I get back to enjoying the feeling of the water flowing around me, I can usually get the 2 strokes back again.
I've also had the experience where, when sharing a lane early in the morning, I was consciously trying NOT to pass my lane-mate. Focusing on gliding more and slowing my stroke. To my surprise, I swam faster!