An Aerobar for Swimmers: Body Position and Balance in the Water

By Ken Mierke

Wouldn’t it be nice if swimmers could buy an aerobar (hydro-bar?) or a disk wheel that could help them swim faster and more efficiently just by tightening a few bolts? The bad news is that there isn’t much equipment that can help a triathlete swim faster. The good news is that you can dramatically decrease body drag without purchasing any equipment. Making simple adjustments to your body position will accomplish this.

Effective triathlon swimming, just like cycling and running, is about efficiency more than it is about strength and fitness. Certainly long and hard workouts are important for optimal performance, but the first swimmers out of the water aren’t necessarily the strongest. Go to any Masters Swim team and you’ll see guys in lane five, the slowest lane, with 6-pack abs. Every Masters team lane 1, the fastest lane, also has a guy who swam in college, but is 40 pound overweight and a two pack a day smoker. Hard and long training is necessary to swim your best in triathlon, but developing an efficient stroke is even more important.

Swimming speed is a result of propulsion minus drag. The best way for almost every swimmer to get faster is to swim through a smaller hole in the water. Improving body position in the water is the area of the greatest potential improvement. The time spent on the side should be maximized so the shoulders do not break the water-line and do not produce bow waves. Dryland swim machines such as the DrySwim Trainer promotes the user to use the core muscles that are needed to rotate the hips and shoulder from one side to the other. This reduces the frontal cross-section, reducing drag further, and also increasing the ratio between the body's water-line-length and width. Similar improvements are possible by orienting the narrowest direction of head, hands, legs and arms into the water.

While each swimmer will develop his/her own style, there will always be fundamentals. It is hard to argue with physics.

Horizontal Body Position: Efficient swimmers maintain a relatively horizontal position in the water to minimize frontal area and drag. Less efficient swimmers legs and hips stay lower in the water, increasing frontal area and drag enormously.

Human swimmers are buoyant, we are just imbalanced in the water. We float naturally, but not in a horizontal position. A human’s center of mass is located in our hips. Our center of buoyancy is in the chest, caused by the air on our lungs. What pulls us down in the water is located low; what pulls us up in the water is located high. Our heads and chests tend to ride too high in he water and our hips and thighs sink.

There are two ways to keep the hips and legs higher in the water as we swim. The first is very effective at keeping the hips and legs up, requiring tremendous energy. The second requires almost no energy, enlisting the water to do the work for you. Which sounds like a better approach to you?

Many swimmers kick very hard when swimming. While this does keep the legs up, it uses tremendous energy and produces almost no propulsion. Kicking hard is exhausting, causing cardiovascular fatigue while swimming and muscular fatigue during the bike and run. Since the feet move up and down, almost all of the propulsion is produced vertically and very little horizontal propulsion.

A more efficient way to keep the body horizontal uses the pressure of the water to keep the hips and thighs up. Since the air in a swimmer’s lungs provides most of the buoyancy, balancing the body around this source of floatation is key. Efficient swimmers keep the head, arms, and shoulders low in the water. This causes water pressure to maintain the body’s horizontal position with almost no energy expenditure from the swimmer. There are a number of keys to balancing the body around the position of the lungs to maintain a horizontal position.

Head Position: Most triathletes tend to lift the head when swimming. As anyone who saw the movie Jerry McGuire knows, the human head weighs 10 pounds. This much weight several feet in front of the center of buoyancy has a great affect on balance. Lifting the head only a few inches will cause the legs to drop significantly. Efficient swimmers carry the head in a neutral position, at the same depth in the water as the lungs. During workouts, concentrate on looking at the bottom of the pool and not forward in the lane. Occasionally swim a few lengths alternating several strokes with the head carried high in the water and several strokes with the head positioned lower in the water. Notice that when you carry the head high the feet drop and you naturally kick harder. Pay attention to the decreased effort when you correctly keep the head down.

Entry: At completion of entry, before the arm begins the pull, it needs to be positioned horizontally in the water to minimize drag during the glide. Since the shoulder will be about 10 inches below the surface, the fingertips need to be about 10 inches below as well.

Many swimmers extend the arm forward and begin the stroke with the arm relatively straight and pulling down into the surface of the water. This downward pull, against the resistance of the water, lifts the upper body which causes the hips and thighs to sink.

Efficient swimmers spear down into the water, with the forearm and elbow following the hand and passing through the hole in the water cut by the hand. This entry keeps the upper body lower in the water and positions the arm to initiate a high-elbow catch.

Lengthened Body Position: Longer vessels create less drag as they move through the water. Efficient swimmers reach for the far wall with their fingertips, pulling the shoulder of the lead arm forward and the opposite shoulder down. This reshapes the body from a rectangle into a long triangle and reduces frontal area dramatically, like an aerobar for swimmers.

Stand relaxed with arms at your sides, looking at yourself in a mirror. Notice how wide your shoulders are. Now, without tilting your shoulders, raise your right arm overhead so that the arm is fully extended toward the ceiling. Shoulder width should not have changed. This is how many athletes swim, dramatically increasing hydrodynamic drag as well as reducing propulsion.

Now extend your right arm fully toward the ceiling, reaching as far as possible and feeling a significant stretch in the armpit and shoulder area. Slide the fingertips of your left hand down the left thigh as far as you can, maximally tilting your shoulders. Look how much narrower your shoulders are in this position. This is the position swimmers’ shoulders should achieve for the glide as one arm finishes each pull and the other finishes entry. Reversing this shoulder tilt during the pull also provides an additional source of propulsive power and lengthens your power zone. Reduced drag and greater propulsion equals faster swimming.

Torso Rotation: Good swimmers rotate their torsos dramatically on each stroke. This generates tremendous power, places the body in the sideways position that minimizes frontal area and drag, and enables relaxed arm recovery.

Breathing: Correct breathing is critical to efficient swimming. Research consistently shows better endurance in swimmers who breathe air instead of water.

Many athletes lift the head and shoulders in an unnecessary attempt to get up where the air is. While they do get air, this movement causes the hips and thighs to sink in the water, dramatically distorting their horizontal body position.

Efficient swimmers stay low in the water, actually breathing below the surface of the water. The pulling shoulder creates a vacuum below the surface of the water. Efficient swimmers breathe in this vacuum, called the bow wave, and are able to get air without climbing out with the head and shoulders. This allows them to maintain a horizontal body position and minimizes unnecessary displacement of water.

Most swimmers rotate the shoulders before the head on breathing strokes, attempting to whip the head around at the last second to catch up. Breathing this way causes swimmers to miss the bow wave and requires climbing out. Learn to keep the chin on the shoulder and allow the torso rotation to pull the head around to the breathing position. Breathing right on the shoulder allows a lower head position.

Exhaling underwater allows better timing of breathing. Many swimmers lift the head, exhale, and then inhale. This takes too long and distorts timing and body position.

Keep the forehead low in the water when breathing. Remember that we breathe through our mouths and noses, not our foreheads. Lifting the forehead does not get the mouth and nose higher. Tuck the forehead and breathe to the side and you will swim faster.

Summary

* Keeping the upper body as low in the water as possible is critical to maintaining a horizontal position without unnecessary energy expenditure.
* Maintain a neutral head position, looking at the bottom of the pool, not forward.
* Spear your hand and forearm down into the water on entry.
* Reach forward as far as possible on entry with the lead arm and shoulder.
* Rotate your torso a full 180 degrees on each stroke.
* Keep your head low in the water, breathing to the side very near the pulling shoulder.

About the Author

Exercise physiologist Ken Mierke is a 2-time I.T.U. World Champion and head coach of Fitness Concepts. Ken coaches triathletes, beginner to professional www.Fitness-Concepts.com.

Source : Tri-Newbies Online