The velocity of a swimmer in any stroke is determine by the swimmer’s stroke rate (SR) multiplied by the swimmer’s distance per stroke (SR x DPS). They both count equally in determining the swimmer’s speed, yet many coaches place a lot more emphasis on DPS than they do on SR. It seems as if SR has lost some of the attention it deserves.
The truth is that in order to swim fast, a swimmer needs to achieve the ideal DPS and SR. A swimmer’s DPS is determined by the propulsion and the frontal drag forces. The greater the propulsion and the lower the frontal drag forces, the further the swimmer will go with each stroke taken. The SR of a swimmer is equivalent to the RPM of an engine; that is how many arm strokes are taken per minute. In breaststroke and butterfly, since both arms are pulling at the same time, the SR’s are about half of those of freestyle and backstroke. The ideal SR for a given swimmer depends on many variables, including the event distance, stroke, stroke technique, age, size, kicking speed and physical maturity of a swimmer.
When it comes to measuring SR, there is a lot of confusion. Some coaches prefer to use Cycle Time (CT), which is the time it takes a hand to go from one entry to the next one, or through one cycle. The CT is often referred to as SR but it is not. For example, a 1 second CT is the same as a 120 SR. A 2 second CT is the same as a 60 SR. To make matters even more confusing, some coaches also refer to Cycle Rates (CR), rather than SR, which makes the fly, back, breast and free rates similar.
In the 50 freestyle sprint event, for example, all elite swimmers use a high SR that varies from around 120 to nearly 150. With practice, even young swimmers can achieve a similarly high SR. In the 100 meter freestyle event, most elite swimmers will use a SR of around 100, with some slightly higher. From the 200 to 800 meter freestyle events, the SR varies between 70 and 100, depending on the technique being used. In the 1500 freestyle, also depending on the freestyle technique, we find elite swimmer’s SR varying from 60 to 100. However, in the final meters of the 1500, when sprinting to the finish, these distance swimmers will reach a SR of around 100.
While one might conclude from this observation that a higher SR is always better, that is not necessarily true. With a faster SR, a swimmer may lose propulsion (not hold water as well), or make other technical errors that will increase frontal drag, resulting in a slower swim. It is not unusual for a swimmer to slow the SR by lengthening the stroke and end up swimming faster. That means the hand enters the propulsion phase earlier and/or leaves the propulsion phase later (holding on to water longer).
Determining the ideal SR for each swimmer is not easy. However, at The Race Club we generally find that the SR for most swimmers is too slow, not too fast. To help our swimmers find and sustain the ideal SR, we use a device called the Tempo Trainer, made by Finis. The Tempo Trainer is essentially a metronome for swimmers. Worn under the cap (or on the goggle strap) and near the ear, it produces an audible beeping sound at a given interval of time which enables swimmers to reach and hold the desirable SR during practice. It has separate modes for SR and CT, depending on the coach’s preference.
The original Tempo Trainer was used by the famous coach Soichi Sakamoto of Hawaii in the late 1930’s, as described in The Three Year Swim Club by Julie Checkoway. Coach Sakamoto borrowed a metronome from music class in his school and would hold it up to his swimmer’s ears before practice, setting it at the desired SR. With this technique, his swimmers went on to set world records and win National Championships. It was as valuable then as it is today.
This week, in Lanes 1-4 on our Race Club subscription service, you will find a complementary webisode (link) on how to use the Tempo Trainer. You will also find Race Club Coach Troy trying his best to get an ol’ dog (me) to increase his SR for a sprint freestyle race. We hope you enjoy this webisode and will start using the Tempo Trainer in your daily practices.
Yours in Swimming,