Swimming Efficiency: Understanding, Measuring, and Improving Your Performance

How do you calculate swimming efficiency?

Swimming efficiency is primarily calculated by assessing the balance between speed and stroke economy, most commonly through the Swim Golf Score (SGS), which combines your stroke count and time for a given distance.

Understanding Swimming Efficiency

Swimming efficiency is a critical concept for swimmers of all levels, from beginners to elite athletes. It fundamentally refers to your ability to move through the water with the least amount of energy expenditure for a given speed or distance. An efficient swimmer maximizes propulsion while minimizing drag, leading to faster times, reduced fatigue, and a lower risk of injury.

Why is Efficiency Important?

• Energy Conservation: Less effort for the same speed means you can swim longer or faster.
• Increased Speed: Efficient mechanics allow you to apply force more effectively, translating to greater velocity.
• Injury Prevention: Good technique reduces strain on joints and muscles.
• Performance Optimization: It's the cornerstone of sustainable improvement in swimming.

At its core, efficiency in swimming is about the intricate interplay between propulsion (the force you generate to move forward) and drag (the resistance you encounter from the water). Maximizing the former while minimizing the latter is the ultimate goal.

Key Metrics for Measuring Swimming Efficiency

While "efficiency" can be a broad term, specific metrics allow for its quantification.

• Stroke Count (SC): This is the number of complete arm cycles (e.g., right arm entry to right arm entry) it takes to cover a specific distance, typically a pool length (e.g., 25 or 50 meters/yards). A lower stroke count for a given speed generally indicates greater efficiency, as you're covering more distance per stroke (DPS).
• Time (T): The duration it takes to cover a specific distance. This is the ultimate measure of speed.
• Distance Per Stroke (DPS): How far you travel with each stroke cycle. A higher DPS indicates more efficient propulsion and less wasted movement. It's calculated by Distance / Stroke Count.
• Stroke Rate (SR): How many strokes you take per minute (or per unit of time). This relates to the tempo of your swim. A higher stroke rate means faster arm turnover.

The Swim Golf Score (SGS) Method

The most common and practical method for calculating swimming efficiency, especially for individual swimmers, is the Swim Golf Score (SGS). This simple yet powerful metric combines your stroke count and time for a specific distance, typically a pool length.

How to Calculate SGS:

1. Choose a Distance: Typically one length of a pool (25 or 50 meters/yards).
2. Perform a Test Swim: Swim the chosen distance at a consistent, comfortable pace that you could maintain for a longer swim.
3. Count Your Strokes: As you swim, count every complete arm cycle. For example, if you start with your right arm, count "1" when your right hand enters the water, "2" when it enters again, and so on, until your lead hand touches the wall.
4. Record Your Time: Simultaneously, time how long it takes you to complete the distance.
5. Apply the Formula: Swim Golf Score (SGS) = Stroke Count + Time (in seconds)

Example:

• Distance: 25 meters
• Stroke Count: 15 strokes
• Time: 20 seconds
• SGS = 15 + 20 = 35

Interpreting Your SGS:

• Lower is Better: A lower SGS indicates greater efficiency. It means you are covering the distance with fewer strokes (better DPS) and/or in less time.
• Balancing Act: SGS forces you to find a balance between stroke economy (low stroke count) and speed (low time). It's easy to lower your stroke count by gliding excessively, but this will increase your time. Conversely, a high stroke rate might reduce your time but significantly increase your stroke count. SGS encourages you to optimize both.
• Progress Tracking: Regularly performing SGS tests allows you to track your improvement over time. As your technique improves, your SGS should decrease.

Advanced Metrics and Considerations

While SGS is excellent for practical application, more advanced methods exist for deeper analysis of swimming efficiency.

• Critical Swim Speed (CSS): This is the theoretical maximum speed you can maintain aerobically, often considered your "lactate threshold" pace in the water. It's calculated from two maximal efforts over different distances (e.g., 200m and 400m). CSS is a strong predictor of endurance swimming performance and can be used to set training paces. While not a direct efficiency calculation, improving your CSS indicates improved efficiency at higher intensities.
• Propulsive Efficiency: This refers to the percentage of the force you generate that actually contributes to forward motion, as opposed to wasted forces (e.g., pushing water downwards). This is highly complex and typically requires specialized lab equipment (e.g., force plates on hands, computational fluid dynamics) to measure accurately.
• Drag Coefficient: A measure of how much resistance your body creates in the water. A lower drag coefficient indicates a more streamlined body position. This is also typically measured in controlled lab environments.
• Physiological Markers: For competitive athletes, efficiency can also be inferred from physiological data such as heart rate (HR), perceived exertion (RPE), and oxygen consumption (VO2) at specific speeds. Lower HR or RPE for a given speed indicates greater physiological efficiency.

Improving Your Swimming Efficiency

Calculating your efficiency metrics is only the first step. The real benefit comes from using this data to inform your training and improve your technique.

• Focus on Body Position: A high, streamlined body position reduces frontal drag significantly. Keep your head neutral, core engaged, and hips high.
• Optimize Your Catch and Pull: The "catch" (the initial engagement of the water with your hand and forearm) is crucial for propulsion. Focus on a high elbow and pulling water straight back, not downwards.
• Develop a Strong Kick: While the arms provide the majority of propulsion, a consistent, propulsive kick contributes to streamlining and stability, reducing drag and aiding propulsion.
• Vary Stroke Rate and Distance Per Stroke: Experiment with different tempos. Sometimes increasing your stroke rate slightly can reduce your time without significantly increasing your stroke count, leading to a better SGS. Other times, focusing on a longer, more powerful stroke can be beneficial.
• Incorporate Drills: Specific drills (e.g., sculling, single-arm swimming, kickboard drills, streamline drills) are designed to isolate and improve aspects of your technique crucial for efficiency.
• Strength and Conditioning: Dry-land training that strengthens your core, lats, shoulders, and triceps will directly improve your ability to generate propulsive force and maintain a stable, efficient body position in the water.

Conclusion

Calculating swimming efficiency, particularly through the accessible Swim Golf Score, provides invaluable objective feedback on your technique and progress. It shifts the focus from merely swimming faster to swimming smarter. By understanding the interplay of stroke count and time, and consistently working to lower your SGS, you'll develop a more powerful, sustainable, and ultimately faster stroke, unlocking your full potential in the water.