Johnson, M. B., Edmonds, W. A., Jain, S., & Cavazos Jr., J. (2009). Analyses of elite swimming performances and their respective between-gender differences over time. Journal of Quantitative Analysis in Sports, 5(4), Article 2, pp. 18.

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This study analyzed the progression of USA swimming records or fastest times for the year from 1962 to 2007 in open and age-group classifications.

Study 1

Records or fastest times for the year were analyzed for 10 events from 1962 to 2007 (all 100 m events, and 200 m freestyle for both genders). The progression of the 50 m freestyles from 1980 to 2007 were also analyzed. This facilitated analyzing one stroke over three distances (freestyle) and all strokes over one distance (100 m). Lines of best fit were calculated for each progression for up to three orders.

Of the 12 events, only the women's 50 m freestyle exhibited a linear progression. The remaining events indicated a slowing of improvement because of a significant second-order regression. A further third-order relationship (the line of best fit) was revealed for the 200 m freestyles and the men's 100 m butterfly [indicating a slowing of improvement followed by an acceleration of improvement].

Gender differences were significantly represented by second-order regression equation but in three events (50 m FR, 100 m FR, and 100 m FL) a third-order equation was the best fit.

Implications. These results indicate "that athletic [swimming] performance is neither improving in a linear fashion nor accelerating at the elite level for (a) swimming events with a range of anaerobic and aerobic emphases or (b) any of the swimming strokes. Additionally, females do not appear to be closing the performance gap with males in elite competitive swimming" (p. 6). In the latter years, ever-slowing rates of improvement in elite USA swimming are occurring in all events save the women's 50 m freestyle.

Study 2

As close as was feasibly possible, data for each decade were analyzed. Because of missing values, six events were considered (50 m, 100 m, and 200 m FR; 100 m BK; 100m BR; 100 m BF) and compared for both genders across five age-groups (10 and under through 17-18 yrs).

No events represented a linear progression. Of the 60 events, 52 were best fit with a third-order regression equation (a slowing followed by an acceleration). The remaining eight events were best represented by a second-order regression, indicating that their progress was slowing (lessening). Gender differences were mostly consistent across age-groups and events.

Implications. "The majority of performances from elite youth swimmers [USA] over approximately the last four decades of the 20th century presented no distinguishable trend in performance changes. . . This supports the argument that the data for 48 of the 60 events do not show a strong trend toward improvement. . . for between-gender performance trends very little significance was found as only three events identified that the performance gap between boys and girls was narrowing. . . between-gender differences do not, for the vast majority of events, appear to be narrowing or growing. They ebb and flow." (p. 13). There is some inconsistency between age-groups with regard to improvements in events within those ages.

General Implications of the Two Studies

The period of analysis of this study involved rule changes, training advancements, and technological innovations (e.g., bodysuits). While rule changes prior to 2000 did produce some third-order regression trends [they accelerated event improvements after a period of slowing], innovations in this decade up to 2007 were not reflected in either age-group or mature elite swimmers. Those trends were consistent across the genders.

Of particular importance, is the lack of effect of the 20th century pre-2008 swimsuit-revolution. Despite the consistent claims of manufacturers of performance improvements mainly through very large reductions in resistance, those claims were not reflected in the best performances in USA swimming. Since recent swimsuit construction has returned to pre-2008 standards, one should not expect today's suits to have any notable effect on performance [unlike the post-2007 to 2010 suits]. Despite swimsuit manufacturers returning to the pre-2008 unsubstantiated claims of swimsuit-effects, one should expect no benefit from any form of the suits, particularly since the amount of material in the suits has been limited to a much greater degree than in the "full-bodysuit" days (pre-2008).

The cost of competitive swimming suits seems to be related to the amount of material contained in the suit as well as the type of material used. It would be advisable and financially responsible to opt for the least expensive suits, particularly for age-group swimmers. Paying extra for a more expensive competitive swimsuit would not be money well-spent as there would be no advantage yielded to the swimmer. That assertion is supported by other technological reasons offered within the Swimming Science Journal ( It can be reasonably believed that the current swimsuit offerings for racing do not enhance swimming performances, do not fulfill manufacturers' claims, and are unreasonably marketed/priced.

Return to Table of Contents for Hydrodynamics of Swimming.

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