Swimming Efficiency: SWOLF
Your Stroke Economy Score - Lower is Better
What is SWOLF?
SWOLF (Swim + Golf) is a composite efficiency metric that combines stroke count and time into a single number. Like golf, the goal is to minimize your score.
Formula
Example: If you swim 25m in 20 seconds with 15 strokes:
Normalized SWOLF for Pool Comparison
To compare scores across different pool lengths:
SWOLF Benchmarks
Freestyle - 25m Pool
National/international level, exceptional efficiency
High school varsity, college, masters competitive
Regular training, solid technique
Developing technique and conditioning
Other Strokes - 25m Pool
Backstroke
Typically 5-10 points higher than freestyle
Breaststroke
Wide variation due to glide technique
Butterfly
Similar to freestyle for skilled swimmers
⚠️ Individual Variation
SWOLF is influenced by height and arm span. Taller swimmers naturally take fewer strokes. Use SWOLF to track your own progress rather than comparing to others.
Interpreting SWOLF Patterns
📉 Decreasing SWOLF = Improving Efficiency
Your technique is getting better, or you're becoming more economical at a given pace. This is the goal over weeks and months of training.
📈 Increasing SWOLF = Declining Efficiency
Fatigue is setting in, technique is breaking down, or you're swimming faster than your efficiency allows.
📊 Different Combinations at Same SWOLF
A SWOLF of 45 could result from multiple stroke/time combinations:
- 20 seconds + 25 strokes = High frequency, shorter strokes
- 25 seconds + 20 strokes = Lower frequency, longer strokes
Always analyze the components (stroke count AND time) to understand your swimming strategy.
🎯 SWOLF Training Applications
- Technique Sessions: Aim to reduce SWOLF through better catch, streamline, and body position
- Fatigue Monitoring: Rising SWOLF indicates technique breakdown—time for a break
- Pace-Efficiency Balance: Find the fastest pace you can hold without SWOLF spiking
- Drill Effectiveness: Track SWOLF before/after drill sets to measure technique transfer
Measurement Best Practices
📏 Stroke Counting
- Count each hand entry (both arms combined)
- Start counting from first stroke after push-off
- Count up to wall touch
- Maintain consistent push-off distance (~5m from flags)
⏱️ Timing
- Measure from first stroke to wall touch
- Use consistent push-off intensity across laps
- Technology (Garmin, Apple Watch, FORM) auto-calculates
- Manual timing: Use pace clock or stopwatch
🔄 Consistency
- Measure SWOLF at similar paces for comparison
- Track during main sets, not warm-up/cool-down
- Note which stroke type (freestyle, back, etc.)
- Compare same pool length (25m vs 25m, not 25m vs 50m)
SWOLF Limitations
🚫 Cannot Compare Between Athletes
Height, arm length, and flexibility create natural stroke count differences. A 6'2" swimmer will have a lower SWOLF than a 5'6" swimmer at the same fitness level.
Solution: Use SWOLF for personal progress tracking only.
🚫 Composite Score Hides Details
SWOLF combines two variables. You can improve one while worsening the other and still have the same score.
Solution: Always examine stroke count AND time separately.
🚫 Not Pace-Normalized
SWOLF naturally increases as you swim faster (more strokes, less time, but higher total). This isn't inefficiency—it's physics.
Solution: Track SWOLF at specific target paces (e.g., "SWOLF at CSS pace" vs "SWOLF at easy pace").
🔬 The Science Behind Swimming Economy
Research by Costill et al. (1985) established that swimming economy (energy cost per unit distance) is more important than VO₂max for middle-distance performance.
SWOLF serves as a proxy for economy—lower SWOLF typically correlates with lower energy expenditure at a given pace, allowing you to swim faster or longer with the same effort.
SWOLF Training Drills
🎯 SWOLF Reduction Set
8 × 50m (30 seconds rest)
- 50 #1-2: Swim at comfortable pace, record baseline SWOLF
- 50 #3-4: Reduce stroke count by 2, maintain same time → Focus on length per stroke
- 50 #5-6: Increase stroke rate slightly, keep stroke count same → Focus on turnover
- 50 #7-8: Find optimal balance—aim for lowest SWOLF
Goal: Discover your most efficient stroke count/rate combination.
⚡ SWOLF Stability Test
10 × 100m @ CSS Pace (20 seconds rest)
Record SWOLF for each 100m. Analyze:
- Which 100m had lowest SWOLF? (You were most efficient)
- Where did SWOLF spike? (Technique breakdown or fatigue)
- How much did SWOLF drift from first to last 100m?
Goal: Maintain SWOLF ±2 points across all reps. Consistency indicates strong technique under fatigue.
Efficiency is Earned Through Repetition
SWOLF doesn't improve overnight. It's the cumulative result of thousands of technically sound strokes, deliberate practice, and mindful attention to efficiency over speed.
Track it consistently. Improve it gradually. Watch your swimming transform.