DiverfromBaskingRidge - 9/12/2017 2:15 PM

Watch this youtube video and see if it helps you understand why the down stroke is more powerful than the upward stroke. After he explains how to flutter kick he does it in the water and you can see the fin in action - the down stroke is pushing the diver forward the up kick is actually bending the fin and not providing much forward motion.

Depending on your own kick - you may want to get someone to video you - GoPro is great for this... and then you can see what you are actually doing vs thinking you are doing... :-)