One of the most common technique errors I see in swimmers with the freestyle stroke is the use of a wide scissor kick instead of a compact flutter kick. Usually, the scissor kick is happening unknowingly, most often in conjunction with two technique errors—both involving breathing: a lifting of the head to breathe and/or over rotating to breathe.
When you lift your head for the breath, the hips begin to drop. The body senses this and the legs splay in an effort to stop the sinking and allow the breath to happen. The sinking usually happens anyway, however, and this is detrimental because once the hips drop, the body assumes an “uphill” position in the water, and drag is increased. Basic streamlining in the water is also affected when the legs move outside the shadow of the body.
When you over rotate for the breath (shoulder pulls too far back and you’re looking at the sky oftentimes as you inhale), the legs will split to stop you from flipping over, basically.
Have one of your friends or family members watch you or break out their phone and videotape you the next time you swim. Have them watch for the scissor kick (easiest to see if filmed while you are swimming away from them) and also have them try to identify if you are lifting or over rotating for the breath.
The solution to eliminating the scissor kick in most cases is to do what is counter intuitive when breathing. First, regarding lifting for the breath, we as humans are programmed to find the air, so if it’s above us—like when we’re swimming—we tend to lift to get it. The counter intuitive part is to roll for the breath instead, taking it when the mouth is resting at or near the waterline. Imagine a skewer running through the top of your head—one that points to the opposite end of the pool—and rotate your head on this axis. If you do so, your hips will remain at the surface (no sinking) and thus, you won’t need a scissor kick to keep you afloat.
If you’re a head lifter, a drill for learning the proper head rotation for breathing is a basic kick-on-the-side drill (also called streamline drill or skating drill). Your body will be angled at a comfortable position on its side, head down, hips at the surface, bottom arm extended in front of you (palm down) and top hand at your side. From this position, rotate your head on the long axis to get your breath. Think about bringing your chin to your shoulder. For many swimmers, rolling the shoulder back slightly to initiate the head movement helps here. If your hips are on the surface and you’ve rolled your head in a level manner, you’ll clear for the breath.
Because you are moving so slowly during this drill, to ensure a level roll of the head, you might have to take your breath looking straight up (a drill breath). Yes, you would be over rotating in this case, but it’s for the specific reason of teaching a level head roll. The important thing here is that you are practicing the proper rolling motion of the head. I watch all the time as swimmers “cheat” on this drill and lift their heads to grab a quick breath, imprinting the same movement they do when they swim. So, keep the head roll level and roll farther than normal to get the breath, if necessary, to ensure an even movement. When you add the momentum that comes from a full swim stroke, you will not have to rotate your head so far to get the breath. But, you will have ingrained the proper movement pattern (no lifting) to initiate the breath correctly.
If you over rotate to breathe, you have the rolling part correct, but you are probably not comfortable taking a breath with your mouth near the waterline. You can practice this while standing in shallow water. Lay your ear in the water, waterline running across your lower lip and bottom goggle, and spend some time breathing here (in through the mouth, out through the nose). Sounds a little weird, I know, but you want to get used to that feeling of having the water next to your mouth and sometimes rolling into your mouth while you’re inhaling. You can also take the time to view the water through the lower goggle to reference the surface in a proper breathing position relative to your goggle. If you increase your awareness of your positioning in this way, you will be better able to identify the tendency to over rotate while you’re swimming.