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Published on: January 14, 2014
Lung Volume-Dependent Decrease in Projected Frontal Area Contributes to Reducing Active Drag in Front Crawl.
Sohei Washino1, Akihiko Murai1, Hirotoshi Mankyu2
1Human Augmentation Research Center, National Institute of Advanced Industrial Science and Technology, Kashiwa, Chiba, JAPAN.
Increasing lung volume in swimmers reduces projected frontal area (PFA), which directly lowers active drag during front crawl. This finding highlights the impact of lung volume on swimming efficiency.
Area of Science:
- Biomechanics
- Fluid Dynamics
- Sports Science
Background:
- Swimming performance is influenced by drag forces.
- Reducing drag is crucial for improving swimming speed and efficiency.
- The role of lung volume in modifying body shape and drag is not fully understood.
Purpose of the Study:
- To investigate if a decrease in projected frontal area (PFA) due to lung volume changes reduces active drag in front crawl swimming.
- To quantify the relationship between lung volume, PFA, and drag.
Main Methods:
- Twelve male swimmers performed front crawl at a set speed with maximal inspiration (INSP), maximal expiration (EXP), or intermediate (MID) lung volumes.
- An underwater motion-capture system and 3D body scanning created digital human models.
- Image processing calculated PFA and pressure drag index (PDI) for body segments.
Main Results:
- Significant interactions were found between lung volume and body segment for PFA and PDI (p < 0.001).
- Head, trunk, and femur segments showed smaller PFA and PDI in INSP and MID conditions compared to EXP (p ≤ 0.046).
Conclusions:
- Increased lung volume leads to a reduced PFA.
- This PFA reduction directly contributes to decreased active drag in front crawl swimming.
- Lung volume is a modifiable factor for optimizing swimming hydrodynamics.
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