Q: "I saw your post on your Facebook page, Triathlon Mom, about swimming tips, and no matter how I position my head, my legs still sink. Any suggestions?" –Robert H., Eldersburg, Md.
A: Though incorrect head position is often one of the main causes of sinking legs, it is not the only one. If your head is positioned correctly — the very top of your head pointing in the direction you want to go and eyes looking straight down toward the bottom of the pool — then something else is likely to blame.
Weak core muscles is the second-most common cause of sinking legs. Swimming.about.com notes that if your core is not strong, it makes it difficult to hold your legs up and more likely that you will fold around your belly, causing the legs to sink. "Any exercises you can do to strengthen your midsection — all the way around, not just the abs — should help," according to the site.
Holding your breath is another possible culprit. If you don't exhale into the water, your chest will be too buoyant, lifting you up in front, in turn causing your legs to sink.
"If you have sinky legs, exhalation should be the very first thing you work on in your stroke," states http://www.swimsmooth.com.
According to http://www.220triathlon.com, leg and lung buoyancy are also possible causes of sinking legs. People with a high muscle-to-fat ratio tend to have dense legs, which resist floating horizontally. Because dense legs are less buoyant, they tend to sink, increasing drag. Practicing kicking drills to improve your kick will help you gain additional lift and propulsion to help counteract sinking legs.
Conversely, the lungs, since they hold air, are naturally buoyant. According to http://www.220triathlon.com, pushing the chest into the water can cause a "downhill" that can help to tilt the whole body, raising the legs.
Finally, a good swim "catch" — the initiation of each stroke — presses the water backwards and propels you forward, while a poor swim catch presses downward on the water, lifting your front end and causing the legs to sink.
"The reasons behind the sinking leg syndrome are many and varied," 220triathlon.com notes, but tweaking your overall swimming habits and techniques is the key to overcoming the problem.