Why The Fundamental Law of Drag Matters in Swimming

Courtesy of Gary Hall Sr., 10-time World Record Holder, 3-time Olympian, 1976 Olympic Games US Flagbearer and The Race Club co-founder.

Drag refers to the forces that slow us down in the water, as we are moving forward. I consider frontal drag the number one enemy of the swimmer. In the medium of our sport, water, which is about 800 times denser than air, drag forces impact the speed of a swimmer at significantly lower speeds than in air. In addition, drag forces in water are extremely sensitive to minute changes in our shape and are exponentially related to our speed. That simply means that the faster a swimmer becomes, the more critical the technique is.

There are three different types of drag forces that slow swimmers down; pressure (form) drag, surface (wave) drag and friction.

In a study done in 2008, Mollendorf, Termin et al showed that all three types of drag affect the speed of swimmers that were being towed on the surface (1). At slower speeds (less than 1 meter/second), pressure drag was the biggest contributor to slowing, while at higher speed, friction became more important. Adding the motions of the arms and legs of a swimmer doing any stroke complicates the contributions of these drag forces by constantly changing the swimmer’s shape and speed. Nonetheless, coaches and swimmers must be mindful of the details that help reduce these forces in order to attain the best possible performance.

Frontal drag forces are so important in swimming, that they overshadow the importance of propulsive power. Power is still important, but in the world of swimming, frontal drag trumps power.

At The Race Club, we pay attention to the minute details that will impact frontal drag. In freestyle alone, I can think of ten different ways a swimmer can reduce frontal drag. The following is a Race Club video link that highlight a few of these and will help you slip through the water with less resistance, reducing your frontal drag, and increase your swimming speed.


Gary Hall, Sr., Technical Director and Head Coach of The Race Club (courtesy of TRC)

Gary Hall, Sr., Technical Director and Head Coach of The Race Club (courtesy of TRC)

Yours in Swimming,

Gary Hall Sr.

1. Mollendorf Joseph C.: Termin Alber C.; Oppenheim Eric; Pendergrast David (2008) Effect of swim suit design on passive drag, Medicine and Science in Sports and Exercise ISSN 0195-9131 CODEn MSPEDA

[email protected] <http://[email protected]  
Www.theraceclub.com <http://Www.theraceclub.com  


The Race Club, logoBecause Life is Worth Swimming, our mission is to promote swimming through sport, lifelong enjoyment, and good health benefits. Our objective is for each member of and each participant in The Race Club to improve his or her swimming performances, health, and self-esteem through our educational programs, services and creativity. We strive to help each member of The Race Club overcome challenges and reach his or her individual life goals.

The Race Club provides facilities, coaching, training, technical instruction, video, fitness and health programs for swimmers of all ages and abilities. Race Club swim camps are designed and tailored to satisfy each swimmer’s needs, whether one is trying to reach the Olympic Games or simply improve one’s fitness. Our programs are suitable for beginner swimmers, pleasure swimmers, fitness swimmers, USA swimming or YMCA swimmers, or triathletes; anyone who wants to improve swimming skills. All of our Race Club members share an enjoyment of being in the water and use swimming to stimulate a more active mind and body.

Leave a Reply

Notify of

oldest most voted
Inline Feedbacks
View all comments
A. Non
6 years ago

You misstatated the conclusion of the article. The article showed that the type of swimsuit affected the balance between friction drag, pressure drag, and wave drag. Suits that cover the chest increase friction drag but lower pressure drag at higher speeds. Suits that don’t cover the chest have higher pressure drag and lower friction drag at higher speeds.

7 years ago

Thanks for the video!

Rahman azizi
8 years ago

I need swimming program training for 10 to 18 years old
please hallo me

Amy Hall
Reply to  Rahman azizi
8 years ago

You can receive customized training programs for your swimmers through our online coaching. Sign up at the bottom of this page: http://www.theraceclub.com/swim-camps/

lane 0
9 years ago

Doesn’t resistance make you go faster?
we can swim through water a lot more effectively than we can “swim” though air. The more resistance, the better anchored your hand/forearm is.
And your arms don’t really contribute to drag very much because during the pull, the hand is relatively stationary.

I’m a little curious about this.

Reply to  lane 0
9 years ago

The upper arm is not stationary. Much of what he talks about is the relatively fast velocity of the upper arm, which makes it cause more speed-sapping drag than the stationary hand.

Reply to  lane 0
9 years ago

Water’s resistance holds back just as much as it helps forward movement.You can increase propulsion to go forward faster, but that increase in velocity also increases the pressure of water holding you back. To GHS’s point: if you don’t figure out how to reduce the negative resistance (drag) you won’t see the benefits of improving positive resistance (propulsion).

Reply to  lane 0
9 years ago

Anonymous and Chris are right. The upper arm moves forward during nearly the entire underwater pull (except perhaps at the very end of the pull) and contributes much more to frontal drag both by its size and speed. Don’t confuse frontal drag with propulsive drag; that created by the hand or foot moving backward. That drag is desirable in order to create as much of a propulsive force as possible.
If you were swimming in outer space (a vacuum) you would not be able to start moving because you would not be able to create propulsive drag. If someone were to push you forward, however, you would not stop, as there would be no frontal drag.