Next time you try NBK (No Board Kick) try kicking on your side. Kicking on your side is a great way to work on a tight core (which reinforces proper body alignment) and practice breathing.
When you do freestyle flutter kick on your side, you want one arm completely extended in front of your body and the opposite arm glued to your side so the hand is resting just below your hip. The arm that is glued to your side should be dry as you kick, try not to let it sink under the water.
Focus on keeping your core tight because if your core is wobbly, it will be difficult to swim in a straight line. Your body is going to follow what your head/arm are doing but you will be able to adjust them by keeping your core straight.
You want your ear to be glued to your leading arm’s shoulder. When you need to breath, focus on a slight tilt of your head – only lifting enough so that your mouth breaks the surface of the water. Once you have breathed, tilt your head back down. Try to maintain your ear’s contact with your shoulder as much as possible during the breath.
I always keep my side kick “symmetrical.” What I mean by that is, whatever distance I do on my right side, I also do on my left. In open water, there isn’t a wall or any lines on the bottom of the pool so you should measure distance by counting your kicks. If you do 7 kicks on your right side, switch to the left and do 7 kicks on that side, etc.
When you switch positions so that the opposite arm is in the lead, all you need to do is half a stroke cycle and you will end up in the same position facing the opposite direction.
In a pool it is easy to measure distance because most pools are 25 yards or 50 meters long. You can kick on your right the entire length of the pool and then kick on your left on the way back. You can kick half way on your right side and then half way on your left side. You can kick on your sides between the flags. You can switch sides every 7 kicks, or whatever pattern you choose.
Kicking on your side can be done slowly and perfectly during warm up/ warm down or it can be done quickly during a main set. It is important to practice kicking without a board and can also be quite challenging – even for veteran swimmers/triathletes. It can be done with or without fins. It can also be done on your back, but I’ll save that for another post.
I am aware that a lot of triathletes save their legs during the swim portion of the race, but don’t let that stop you from practicing your kick. Developing a strong kick will make every other aspect of swimming easier for you in the long run. Do not ignore your legs during your swim practices! Believe me, I was never the worlds strongest kicker (and probably anyone I trained with will confirm that) but I was always trying to become a stronger kicker so that I would become a better swimmer.