Often times at tweak, especially with triathletes, we see kicks that involve way to much drive from the knee downward towards the bottom of the pool. This projects a greater frontal surface area, which creates more drag and thus more work.
To kick efficiently you want to concern yourself with mostly lifting the leg up towards the surface and doing very little downward motion at all. The freestyle flutter kick has more in common with walking backwards on your tip toes than any other movement we do. It's not like walking and it's definitely not like riding a bike.
Another big problem we sees while improving kicks in our Swim Analysis appointments at tweak is toes pointing outward. The mark of the breast stroker. For those of you out there with that predisposition try to turn your toes in towards the center of your body and imagine pointing them at the same point on the wall back behind you. This again will reduce the amount of frontal surface drag and have you moving through the water with less effort.
Click below to watch the fix in action!