Analysis of Swimming Resistance

Performance Level Differences in Swimming: A Meta-Analysis of Resistive Forces
Rod Havriluk, Ph.D.
Research Quarterly for Exercise and Sport, 2005, 76(2), 112-118.
 
The streamline is the most basic position in competitive swimming and has been used in many studies on resistive forces. However, there is a wide variety of theoretical interpretations in these articles, leading to diverse and questionable conclusions.
 
For example, one study found that there was no difference between skilled and unskilled swimmers in drag force and concluded that they were hydrodynamically similar. Since drag force is dependent on body size as well as hydrodynamic characteristics, larger skilled swimmers could have the same drag as smaller unskilled swimmers. For an accurate comparison of skill levels, it is more appropriate to use the drag coefficient.
 
The purpose of this study was to determine performance level differences in the streamline position using a meta-analysis. It was hypothesized that higher performance level swimmers would have a more effective streamline as measured by a lower passive drag coefficient.
 
Data from 19 studies on passive drag were organized by performance level (elite and non-elite) and gender with the coefficient of drag as the criterion variable. As hypothesized, the elite group had a significantly smaller drag coefficient, and therefore, a more effective streamline position. In addition, the elite group males were larger than the non-elite group in their body cross-section.
 
This findings of this study support:
1) the drag coefficient as an appropriate means to discriminate between performance levels;
2) the importance of mastering the most basic skill in competitive swimming (streamline); and
3) the need for considering all the related variables in a study of passive drag.
 

Analysis of Swimming Resistance

analysis of passive drag in swimming