Measuring Improvements in your swimming efficiency

Measuring Improvements in your swimming efficiency

By Mike Koerner, USA Swimming and ASCA Certified Coach

Greetings and welcome to a new and exciting year of Triathlon training. Although the temperatures are finally getting to the winter norms here in Chicago that certainly should not stop you from getting yourself ready for another new triathlon season. Throughout the last year, I have written several articles designed to help improve your swimming efficiency. Whether they were about drills to improve your stroke technique, creative workout ideas to simulate open-water swimming in the pool, or ways to increase your swimming distance per stroke, all these articles had the same end state in mind; getting through the water faster with less effort thus setting us up for a quicker overall race.

While introducing all these novel ideas it occurred to me that I have yet to provide something just as important. Feedback: How can you expect improvement if you have no way of measuring improvement. Or, to put it simply: “Inspect what you expect.” This article is going to cover the ways that you can measure improvement in your swimming.

There are several ways that you can measure improvement in your swimming efficiency. These range from the very easy to the slightly more complicated. Only a couple require some rudimentary math. The first way to measure or gauge improvement in your swimming is simply by time. Can you swim a certain length or set of intervals faster than you could previously? We measure this by using a Test Set. What a test set does is allow you to see improvements in your swimming fitness and perhaps some improvement in swimming speed. It goes something like this: Swim a given distance or interval set and record the times, comparing them to a previous time for that same distance or interval. Faster time or faster average time equals improvement. Here are a couple of examples: After a good warm up swim 500 yards as quick as you can for time. Record the time, and also calculate your average time (or split) per 100. Compare this to a previous effort. Repeat this test approximately every four to six weeks throughout the training cycle and see the improvement. Another test set is to swim a set of either 5 or 10 100 yard swims with a rest interval of 15 seconds between each 100. Record the time for each 100 and then come up with the average time. This is what is known as your T-pace. You can then use this information to develop your interval set for your swimming workouts. (Developing a complete swim training program and designing workouts for triathletes goes beyond the scope of this article.) Once again, perform this test set every four to six weeks and you should see an improvement in your T-pace as the season progresses. Both of these examples will give you some insight into improvements in your swimming fitness but, they only tell half the story. What they won’t tell you is whether or not you are becoming a more efficient swimmer or whether or not your stroke technique has improved. You can make the assumption that this is true based on an improved T-pace but, that could simply be a result of increased strength and endurance. To really know whether or not you are improving your technique and efficiency you need to make a couple of additional measurements. You need to learn how to calculate your distance per stroke and your stroke cycle. These calculations, coupled with T-pace will tell you whether you are getting faster and whether you are more efficient. The calculations are relatively simple and you can use them during your daily training sessions without having to collect significant amounts of data. Additionally, these calculations provide instant feedback on stroke efficiency during any stage of a workout.

Distance per Stroke; by definition refers to the distance a swimmer travels during each stroke cycle. Distance per Stroke (DPS) is calculated as the number of yards/meters your body moves forward during one stroke cycle. Let’s quickly define a stroke cycle. A stroke cycle includes two arm strokes, one with the right, and one with the left. Putting this simply, you are going to calculate the distance you move for each rotation of your arms. There are several ways to calculate DPS. The most accurate method is to use video to measure the distance your body moves forward during one stroke cycle. This would require access to video equipment and someone else to help you out. The most common way to calculate DPS is to count the number of stroke cycles required to complete a known distance, such as the length of a pool, and divide that number into the distance. For example, if it took you 20 stroke cycles to cover 40 meters, then your average DPS would come out to 2.0 meters/per stroke cycle. {40/20=2.0}. How is this useful? By knowing the distance you cover for each of your stroke cycles you can count your strokes and see if that number increases or decreases. The best way to use this in a workout is simply to count your stroke cycles during the workout. For example, I will use 500 meters as the given distance. Count your strokes for one length of the pool (25/50 meters depending on pool size) for every 100 meters you swim until you reach 500 meters. Did the number of strokes per length of the pool increase or decrease? If your stroke cycle increased, you were becoming less efficient per length or your distance per stroke was decreasing as you swam the required distance.

Stroke Rate refers to your cycling or turnover rate and can be expressed as the number of stroke cycles you take each minute (cycles/min) or the time required to complete one stroke cycle (time/cycle). The way to calculate stroke rate is, using a stopwatch, time one stroke cycle. This number will be expressed as time per cycle (time/cycle). An easier and more accurate way to do this would be to time two or more cycles and then find the average by dividing the number of cycles into the time. {ex. Three stroke cycles = 3.30 sec, divide the time by 3 to calculate a result of 1.10 sec/stroke cycle.} Stroke rate can also be expressed as stroke cycles per minute. The values are calculated by dividing the average time per stroke cycle into 60 seconds. Here is the example: You complete three stroke cycles in 3.2 seconds, you divide that by 3 and you get 1.067 sec/stroke cycle. To calculate stroke cycles per minute you take 60 seconds and divide that by your 1.067 sec/stroke cycle and that will give you 57 cycles per minute. This cycle per minute (57) is the number we are after. Stroke cycles per minute is a good way to tell how you performed over a given distance, if your stroke cycles per minute increase over a given distance we are using more effort to cover that same distance and thus we are less efficient. Never fear, if this math seems somewhat intimidating, most swimming stopwatches now have the capability of calculating stroke cycle per minute with just a touch of a button.

Putting it all together. Now that you are able to calculate your distance per stroke and your stroke rate you can use these calculations to provide accurate and instant feedback on your swimming efficiency as well as your endurance. Combining your T-pace along with your distance per stroke you can see if you are going fast and efficient or whether you are going fast but not efficient. By knowing these things you become aware of what you need to focus on to improve your swimming technique. The calculations now provide that feedback mechanism during your workout to alert you to degradation in your technique. If your DPS decreases or your stroke cycle increases per length you know that you are swimming less efficiently. This is most likely caused by a breakdown in technique coupled with some fatigue. The issue of fatigue is tackled by endurance training and strength. The breakdown in technique is tackled by performing the stroke correctly, this adjustment you can make during your workout. The goal is to perform the distance or interval at the same speed (T-pace) while not letting your DPS decrease or stroke rate increase. Here is what I mean; if your DPS is decreasing you are not staying long in your stroke, generally caused by swimming flat without rotation or not finishing your stroke. You can counter that by thinking of torpedo drill and the rotation of the hips. If you rotate your hips your stroke should lengthen and DPS should increase. Additionally, if you think about push drill, you will ensure that you are pushing your hands past your hips and finishing your stroke thus increasing your DPS. It is also assumed that by increasing your DPS you are decreasing your stroke rate.

As you can see from just that example, the calculations of distance per stroke and stroke cycle provide you instantaneous feedback on your efficiency. By identifying a loss of efficiency during your workout you can quickly apply the appropriate countermeasures or techniques during the workout and once again measure them for expected results. The cycle is complete. You now have two additional measurements to gauge your improvement in swimming efficiency both during and after your workout. Armed with this knowledge, and the previous articles on drills and techniques you will be able to design better swim workouts focusing on the areas you need to improve all the while becoming faster and more efficient. Until next month, Happy Swimming!

Coach Mike is a USA Swimming and ASCA Level 2 Certified coach who coaches competitive triathletes and swimmers from the Age Group ranks up through Masters. Additionally, he is the Director of Swimming at Break Through Multisport Inc. You can reach Coach Mike at Mike@BreakThroughMultisport.com with any questions or comments.

Works Cited/Further Reading

Maglischo, Ernest W., Swimming Fastest, Human Kinetics, 2003.