As the hand continues to move backward, creating propulsion, it passes by the shoulder of the swimmer, entering the back quadrant. At or near this transitional point, the hand reaches maximum propulsion for several reasons. First, the hand is about midway through the propulsive phase and has reached its maximum backward velocity. Second, as the body counter rotates, the shoulder goes from a negative angle during the lift and early propulsive phase to a neutral or slightly positive angle (depending on the elbow position), which is a mechanically stronger position for the pull. Third, the counter-rotation of the body at that moment is in full force, meaning the angular velocity of the body is greatest and the coupling energy for the pull is at a maximum. The party doesn’t last long, however. If one were looking at the swimmer from the side, with the path of the hand making a circle of about 2 feet in diameter (recall that the body is moving forward as the hand is moving backward), the hand does not follow the perimeter of the clock from 6 o’clock to 9 o’clock. If it did, any upward force of the hand would push the body lower in the water, resulting in less propulsion and more frontal drag. Rather, shortly after passing the shoulder (6 o’clock), the arm and hand elevate and the wrist dorsi-flexes (bends backward) in order to try to maintain the greatest possible surface area as the hand continues to push backward.
By the time the hand reaches 9 o’clock, the party is officially over. The arm (elbow) is fully extended backward. From 6 to 9 o’clock, the speed of the hand decelerates from its maximum to zero, and the propulsion drops accordingly, all within a little more than a tenth of a second.
In velocity meter studies performed at The Race Club, I am amazed at how quickly the velocity of the swimmer’s body changes during the pulling cycle. Each arm has a peak velocity point and a trough velocity point that occurs within a few tenths of a second of one another. In efficient swimmers, we usually see the difference between peak and trough velocities is less than .5 meters per second. Not so with poor swimmers, where I have seen differences of .7-.8 meters per second. The peak velocity point typically occurs when one pulling hand is at 9 o’clock and the other hand is extended forward. At this point, the propulsion from the pulling arm has just finished, yet the body is in a relatively streamlined position. The trough velocity typically occurs when the pulling hand is near 3 o’clock, just before beginning the propulsive phase. At this point, when the arm (and particularly the upper arm) is no longer positioned along the axis of the swimmer’s motion, it begins causing a huge frontal drag force.
So what are the takeaways from this? First, despite what your coach may have told you, don’t squeeze your fingers together in freestyle … ever. On the recovery, separating your fingers and relaxing your wrist enables the arm to recover better for the next pull. Under water, separating the fingers slightly, while stiffening the wrist, maximizes the effective surface area of the hand, increasing propulsion. When you push the hand backward through the water quickly, the water can’t flow through the small spaces between your fingers fast enough, so the hand acts like it is bigger.
Second, despite what your coach may have told you, don’t push hard with the hand near the back end of the pulling stroke. There is not much power back there. The power starts with your hand about one foot in front of the shoulder and drops off quickly once it passes that point. So get the hand through the pull and back out in front quickly where it helps you more.
Finally, sacrifice some power on your underwater pull by keeping your elbow near the surface during the pulling motion. The mechanical angle of the shoulder may not be as favorable there, but reducing the frontal drag forces caused by your upper arm moving forward throughout most of the underwater pull will more than make up the difference. Your net swimming speed will be greater.
Yours in swimming,
Gary Hall Sr., M.D. is a three-time Olympic swimmer (‘68, ‘72, ‘76) who earned a medal in each of the three Olympic Games. At one time he held 10 world records in all strokes except breaststroke and was the World Swimmer of the year in 1969 and 1970.
Gary Sr. serves as president and technical director of The Race Club Inc. based in Islamorada, Florida. He is the current president of the United States Olympians and Paralympians Association and co-founder of World Fit, a non-profit organization promoting childhood exercise and sports. He has six children, the oldest of whom, Gary Jr., also swam in three Olympic Games (‘96, ‘00, ‘04) and earned 10 Olympic medals. Two other children, Richard and Amy, and his wife, Mary, work with Gary Sr. at The Race Club. In 2006, Gary Sr. retired from ophthalmology to dedicate his remaining professional career to teaching advanced swimming techniques for competitive swimmers and triathletes.
The views expressed in this article are the opinion of the author and not necessarily the practices of USA Triathlon. Before starting any new diet or exercise program, you should check with your physician and/or coach.