[Research Review] Report on the Optimization of Distance Per Stroke (DPS) and Stroke Rate for Long-Distance Freestyle Efficiency: A Study of Elite Swimmers’ Physiological Characteristics (No. 606)

Source Reference: Journal of Sports Sciences • International Scientific Research Review Series

This article explores the trade-off between Distance Per Stroke (DPS) and Stroke Rate in freestyle swimming, and their impact on long-distance freestyle efficiency.

The Efficiency Trade-off Between DPS and Stroke Rate

Swimming speed = DPS × Stroke Rate, and the two are in a trade-off relationship: extending stroke length typically requires a more complete catch and reach, but if the stroke rate drops too low, the excessive speed decay during the glide phase and the discontinuity of overall propulsion can pull down average speed. Conversely, chasing a high stroke rate at all costs tends to sacrifice the catch quality of each stroke, resulting in “spinning.” Long-distance freestyle swimmers mostly achieve their optimal DPS/stroke rate combination at a moderate stroke rate (approximately 55-65 strokes per minute, varying by individual body size and swimming experience), rather than simply pursuing maximum DPS.

Technical Elements for Optimizing DPS

• Early Vertical Forearm (EVF): The forearm is angled as close to perpendicular to the direction of travel as early as possible, increasing the effective propulsive surface area
• Body Rotation: Moderate torso rotation can extend the stroke path and reduce the burden on the shoulder joint working in isolation
• Bilateral Symmetrical Extension: After entry, the arm extends fully forward, avoiding an early downward press into the catch—this is the most direct technical adjustment point for lengthening DPS

Training Data Comparison for DPS and Stroke Rate (Illustrative)

Core Research Conclusions and Practical Recommendations

• Technique over brute force: When DPS is insufficient, prioritize examining the catch path and body rotation angle, rather than simply compensating by increasing stroke rate
• Session design: Alternate “counted swimming” (counting strokes over a fixed distance) with “even-pace swimming” to simultaneously develop DPS efficiency and cardiorespiratory tolerance at race stroke rates
• Fatigue monitoring: A noticeable shortening of DPS in the latter stages of a long-distance swim is an early signal of fatigue or technical breakdown, and can serve as a basis for pace adjustment
• Individualized configuration: Swimmers with greater height and arm span are better suited to a lower stroke rate with a longer DPS strategy; conversely, others may consider a higher stroke rate paired with a shorter but efficient DPS

Common Research Q&A (FAQ)

Q: Is a longer DPS always better?

A: Not necessarily. DPS only matters when paired with stroke rate. Overly pursuing DPS to the point where stroke rate drops too low can actually slow you down due to speed decay during the glide phase and a broken overall rhythm.

Q: How do I know if my DPS is efficient?

A: Record “strokes per 25 meters” together with the time for each lap. The same stroke count with a faster time, or a similar time with fewer strokes, both indicate improved efficiency.

References and Academic Citations

1. Journal of Sports Sciences — Research on the interaction between DPS and stroke rate in freestyle swimming.
2. Sports Biomechanics — Literature on quantitative analysis of EVF catch technique and propulsive efficiency.

Related Reading

• Research Review: Report on the Optimization of Distance Per Stroke (DPS) and Stroke Rate for Long-Distance Freestyle Efficiency: A Study of Elite Swimmers’ Physiological Characteristics (No. 534)
• Research Review: Report on the Optimization of Distance Per Stroke (DPS) and Stroke Rate for Long-Distance Freestyle Efficiency: A Study of Elite Swimmers’ Physiological Characteristics (No. 747)
• Research Review: Report on the Optimization of Distance Per Stroke (DPS) and Stroke Rate for Long-Distance Freestyle Efficiency: A Study of Elite Swimmers’ Physiological Characteristics (No. 258)
• Research Review: Report on the Optimization of Distance Per Stroke (DPS) and Stroke Rate for Long-Distance Freestyle Efficiency: A Study of Elite Swimmers’ Physiological Characteristics (No. 357)