Maintaining a stable core is an important part of a good freestyle. This standard drill is a good one to help accomplish this.

Why Do It:
Freestyle is faster when you rotate through a solid tube in the water, rather than squiggle down the pool. This drill requires the swimmer to tighten the abs a bit to maintain the straight line through the entire body.

How to Do It:
1. Put on a pull buoy at the ankles, not between the thighs as typical.
2. Push off and start swimming.
3. Hold the pull-buoy tight between the ankels by squeezing the legs together.
4. Keep the hips at the surface by tightening the abs.

How to Do It Really Well (the Fine Points):
Limit the side-to-side movement of the legs while you're swimming. Taller swimmers will move a bit more than swimmers who are more vertically challeneged simply because of the longer line. Holding the pull-buoy in for longer swims will also show you another benefit of working the groin and inner parts of your legs.