Consistency of swimming performance within and between competitions.

PURPOSE: The consistency of performance between events impacts how athletes should specialize in events, how competitions should be structured, and how changes in performance affect an athlete's placing in an event. We have therefore determined the consistency of swimming performance in events within and between two national-level competitions.
METHODS: We used mixed linear modeling to analyze official performance times of 149 male and 162 female swimmers at a junior national championship, and of 117 male and 104 female swimmers at an open national championship 20 d later. The events differed in stroke (backstroke, breaststroke, butterfly, freestyle, and individual medley) or distance (50-1500 m).
RESULTS: Swimmers were most consistent in their performance for the same event between the two competitions (typical variation between competitions, 1.4%; 95% likely range of true value, 1.3-1.5%). They were less consistent between distances of a given stroke within each competition (1.7%; 1.5-1.9%) and least consistent between strokes for a given distance (2.7%; 2.3-3.1%). Variation in performance between the longest continuous freestyle distances (400, 800, and 1500 m) in the open competition was half that between widely spaced freestyle distances (50, 200, and 800 m). Faster swimmers were more consistent (1.1%; 0.9-1.4%) for the same event between competitions than slower swimmers (1.5%; 1.3-1.9%).
CONCLUSIONS: (a) Swimmers are stroke specialists rather than distance specialists; with the present set of events in competitions, they should concentrate training and competing on a particular stroke rather than a particular distance. (b) More swimmers would have a chance of winning a medal if events of a given stroke differed more widely in distance. (c) Factors that affect performance time by as little as 0.5% will affect the placing of a top junior swimmer.