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A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers
Published on: January 28, 2020
Stroke phases responses around maximal lactate steady state in front crawl
Jailton G Pelarigo1, Benedito S Denadai, Camila C Greco
1Human Performance Laboratory, UNESP, Rio Claro, Brazil.
Journal of Science and Medicine in Sport
|October 8, 2010
Summary
Endurance swimmers alter stroke rate and length at intensities above maximal lactate steady state (MLSS). Swimming strategy shifts, notably increasing the pull phase duration, to maintain speed under higher metabolic demands.
Area of Science:
- Sports Science
- Exercise Physiology
- Swimming Biomechanics
Background:
- Understanding physiological and biomechanical adaptations during intense swimming is crucial for performance.
- Maximal lactate steady state (MLSS) represents a key intensity threshold in endurance sports.
- Stroke parameters like stroke rate (SR) and stroke length (SL) are fundamental to swimming efficiency.
Purpose of the Study:
- To investigate how stroke rate, stroke length, and stroke phase durations change at and above maximal lactate steady state (MLSS).
- To analyze the impact of metabolic conditions on swimming biomechanics during prolonged efforts.
- To identify potential shifts in stroke strategy to maintain speed under supra-MLSS conditions.
Main Methods:
- Twelve endurance swimmers completed incremental and constant-speed tests to determine critical speed (CS) and MLSS.
- Swimmers performed 30-minute constant-speed tests at MLSS and 102.5% MLSS.
- Analysis included changes in stroke rate, stroke length, and the relative duration of distinct stroke phases.
Main Results:
- Significant differences were observed between MLSS, 102.5% MLSS, and CS swimming speeds.
- Stroke rate and stroke length remained stable at MLSS but significantly altered at 102.5% MLSS.
- The propulsive pull phase duration significantly increased at 102.5% MLSS, indicating a strategic adjustment.
Conclusions:
- Metabolic conditions significantly influence swimming stroke parameters (SR and SL).
- Swimmers adopt altered stroke strategies, specifically increasing the pull phase, to sustain speed above MLSS.
- These findings highlight the importance of considering metabolic state in optimizing swimming technique for high-intensity, prolonged efforts.
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