What can SWOLF tell us? Interpreting Swim Data from your GPS Watch.
Currently, the most popular platform for tracking and reporting swim data is Garmin. However there are a number of newer competitors on the market with both watches as well as goggles having the ability to track, report and visualize swimming information.
One of the most intriguing and easily accessible metrics provided is the SWOLF score. SWOLF, short for “Swim Golf,” is a score obtained by adding together the number of strokes per length and the time it takes to complete that length.
For example, if you swim 25 yards in 30 seconds and it takes you 20 strokes, your SWOLF score would be 50.
Take a look at the screenshot below, captured from Garmin Connect, showcasing this informative metric:
And here is a similar example from Finis, the makers of the Swim Sense, which is no longer sold, but you can see another way the information is presented. (do you use another brand of watch or goggle to record your swimming? Send a screenshot our way and we may feature it in an update to this series!).
Unveiling the Secrets of SWOLF: What Does It Really Tell Us?
When it comes to SWOLF, many coaches consider it a measure of efficiency, believing that a lower SWOLF score indicates a more efficient stroke. While striving for a lower SWOLF score is a common goal, there are two important factors to consider when analyzing SWOLF and its relationship to efficiency. Let’s explore these factors and uncover new ways to leverage SWOLF in your workout analysis.
Firstly, It’s essential to grasp the concept of efficiency in swimming. Efficiency refers to the ratio between the energy you invest in your strokes and the resulting forward movement. Accurately measuring efficiency would involve quantifying the amount of oxygen a swimmer consumes while swimming at a particular speed, which requires specialized tools for measuring oxygen consumption. Since swim watches cannot provide a precise efficiency value, we must explore alternative indicators that can offer insights into stroke efficiency.
Now, let’s delve into the second reason why SWOLF alone cannot provide a comprehensive picture of efficiency. While SWOLF is calculated by combining two parameters—Strokes per Length (SPL) and the time taken to complete the length—we still need independent knowledge of both SPL and time to make meaningful interpretations of the SWOLF score.
In essence, SWOLF offers valuable insights into stroke efficiency but should be analyzed alongside additional information to gain a comprehensive understanding. By examining factors such as stroke technique, stroke rate, and overall swimming mechanics, you can paint a more complete picture of efficiency and make informed adjustments to enhance your performance in the water.
Exploring Swim Golf Variations: Understanding Time and SPL Matrix
Let’s explore different combinations of Stroke Per Length (SPL) and time in a simple two by two matrix to understand how they affect SWOLF and what it indicates. Take some time to go through each scenario, and it will provide you with new perspectives on these metrics.
Four Scenarios: A) High SPL and high time = High SWOLF and inefficient swimming B) High SPL and low time = Medium SWOLF and improved efficiency C) Low SPL and high time = Medium SWOLF and very efficient swimming D) Low SPL and low time = Very low SWOLF and inefficient swimming
If if SPL * rate = time, then we are curious about what SPL + time or SWOLF can tell us?
Four Scenarios:
| SPL | |||
| HIGH | LOW | ||
| Time | HIGH | A | C |
| LOW | B | D | |
A) SPL is high and time is high = high SWOLF and inefficient swimming
B) SPL is high and time is low = medium SWOLF and improved efficiency
C) SPL is low and time is high = medium SWOLF and very efficient swimming
D) SPL is low and time is low = very low SWOLF and inefficient swimming
A) When SPL and time are both high, it suggests a lot of drag or an inefficient catch. Swimmers in Scenario A can learn a lot by tracking SWOLF and observing its improvement. A decrease in SPL or an increase in speed indicates improved swim efficiency.
B) As speed increases, it’s normal for SPL to increase (SWOLF may remain the same) in efficient swimming. Swimmers in Scenario B can expect a lower SWOLF for slower swimming and a higher SWOLF for faster swimming. They should aim for a sustainable faster speed and be satisfied with a higher SWOLF while identifying their specific SPL and pace targets for different training distances or race settings.
C) Scenario C suggests a very low stroke rate with a significant amount of glide, indicating highly efficient swimming (SWOLF may be the same as in Scenario B). Swimmers in Scenario C should strive to increase their SWOLF by increasing their tempo since they already possess a highly efficient stroke.
D) Achieving a low SPL while swimming at a high speed requires considerable power and strength. Although SWOLF will be low, true efficiency may be compromised. However, in a race, the fastest time, not the highest efficiency, determines the winner. Swimmers in Scenario D are skilled and powerful, allowing them to adapt their strokes based on the task at hand.
Each scenario provides valuable insights into stroke efficiency, and understanding these variations can help swimmers refine their technique and optimize their performance.
Swimming Efficiency Comparison: Stroke Counts, Times, and SWOLF Scores
In this video, Jai demonstrates an interesting comparison between two lengths of swimming. In the first length, he completes it with 16 strokes in 31 seconds, resulting in a SWOLF score of 47. In the second length, he maintains the same 16 strokes but completes it in just 18 seconds, resulting in a lower SWOLF score of 34.
Despite the faster time in the second length, it’s important to note that the slower length is actually more efficient considering the amount of effort required relative to the forward movement achieved. While Jai could sustain the effort of the first length for a significant distance, the second length would likely be sustainable for a shorter distance, possibly around 100 meters or less.
SWOLF: More Than Just Efficiency
Let’s delve into an interesting aspect: the connection between speed and SWOLF. Imagine plotting different combinations of speed and SWOLF at various stroke rates. We might uncover a valuable self-coaching tool. My hunch, however, is that we can’t rely solely on SWOLF to gain insights. To truly analyze data and improve our swimming practices, we need to consider at least two out of three metrics: stroke count (SPL), time, and speed.
For me, SWOLF serves as a quick measure of consistency rather than an absolute measure of efficiency. When I review my athletes’ watch data, the SWOLF graph tells me if they are taking too much rest or swimming too easily. It also reveals if they are becoming more consistent in their performance during specific sets, such as a set of 10 x 100. While pace alone or SPL alone won’t provide the full picture, SWOLF alone doesn’t tell us much either.
Consider this: If I observe a set of 10 x 100 with a consistent SWOLF and unchanging SPL, it indicates that the swimmers are maintaining a steady level of performance, which is a positive sign. However, to truly understand their progress and enhance their performance as triathletes, I need to combine SWOLF with either pace or SPL. By reducing rest intervals, increasing the distance of each repetition, or ramping up the pace, we can aim for faster swimming and improved fitness, which may impact SWOLF in different ways.
Going Beyond SWOLF: Practical Strategies for Improving Swimming
I hope this discussion has shed light on the significance of various metrics and how to make the most of the information. In my experience, focusing on stroke count ranges, discovering your optimal SPL, experimenting with different SPLs, and maintaining your chosen stroke count—coupled with the use of a tempo trainer (steady, ascending, descending, etc.)—offer greater control and guidance compared to relying solely on SWOLF.
In an upcoming article, I will analyze specific watch data graphs to provide insights into executing swim sets and planning practice sessions for improved skill development. I’m eager to hear your thoughts and learn how you use the watch data you collect. Share your experiences and ideas in the comments section below. Together, we can continue to enhance our swimming performance.