Abstract
aims of the present study were to investigate the changes in the age and in swimming performance of finalists in World Championships (1994–2013) and Olympic Games (1992–2012) competing in all events/races (stroke and distance). Data of 3,295 performances from 1,615 women and 1,680 men were analysed using correlation analyses and magnitudes of effect sizes. In the World Championships, the age of the finalists increased for all strokes and distances with exception of 200 m backstroke in women, and 400 m freestyle and 200 m breaststroke in men where the age of the finalists decreased. The magnitudes of the effects were small to very large (mean ± SD 2.8 ± 2.7), but extremely large (13.38) for 1,500 m freestyle in women. In the Olympic Games, the age of the finalists increased for all strokes and distances with exception of 800 m freestyle in women and 400 m individual medley in men. The magnitudes of the effects were small to very large (mean ± SD 4.1 ± 7.1), but extremely large for 50 m freestyle in women (10.5) and 200 m butterfly in men (38.0). Swimming performance increased across years in both women and men for all strokes and distances in both the World Championships and the Olympic Games. The magnitudes of the effects were all extremely large in World Championships (mean ± SD 20.1 ± 8.4) and Olympic Games (mean ± SD 52.1 ± 47.6); especially for 100 m and 200 m breaststroke (198) in women in the Olympic Games. To summarize, in the last ~20 years the age of the finalists increased in both the World Championships and the Olympic Games with some minor exceptions (200 m backstroke in women, 400 m freestyle and 200 m breaststroke in men in World Championships and 800 m freestyle in women and
200 m breaststroke (198) in women in the Olympic Games. To summarize, in the last ~20 years the age of the finalists increased in both the World Championships and the Olympic Games with some minor exceptions (200 m backstroke in women, 400 m freestyle and 200 m breaststroke in men in World Championships and 800 m freestyle in women and 400 m individual medley in men in Olympic Games) and performanceof the finalists improved. Keywords:Elite swimmers; Age; Performance; Sex difference Background Peaking during the Olympic Games is a major challenge for swimmers, coaches, and scientists (Issurin et al. 2008). Any information that is reliable and valid is of major interest to the athletes and their support (Issurin et al. 2008). Therefore, a large number of investigations were performed to expand the knowledge of peak performance and the age of peak performance in many different sports disciplines such as running (Schulz and Curnow 1988; Berthelot et al. 2012; Lepers and Cattagni 2012), cycling (Schulz and Curnow 1988; Zingg et al. 2013), swimming (Schulz and Curnow 1988; Tanaka and Seals 1997; Rüst et al. 2012, 2014; Buhl et al. 2013b; Kollarz et al. 2013a, b; Vaso et al. 2013; Wolfrum et al. 2013; Allen et al. 2014; Zingg et al. 2014a) and triathlon (Stiefel et al. 2013). As a landmark in the exploration of age and peak athletic performance in elite pool swimmers, Schulz and Curnow (1988) investigated Olympic gold medal winners competing between 1896 and 1980. For freestyle swimming, the age of peak athletic performance was described to be stable at ~18 years for women and at ~21 years for men for almost a century (Schulz and Curnow 1988). In a very recent study, Allen et al. (2014) described the age of individual peak swimming performance in top 16 swimmers competing in the Olympic Games in 2008 or 2012. More studies were done in the field of the age of peak swimming performance, but most of them focused * Correspondence:beat.knechtle@hispeed.ch 1 Institute of Primary Care, University of Zurich, Zurich, Switzerland 2 Gesundheitszentrum St. Gallen, Vadianstrasse 26, 9001 St. Gallen, Switzerland a
of individual peak swimming performance in top 16 swimmers competing in the Olympic Games in 2008 or 2012. More studies were done in the field of the age of peak swimming performance, but most of them focused * Correspondence:beat.knechtle@hispeed.ch 1 Institute of Primary Care, University of Zurich, Zurich, Switzerland 2 Gesundheitszentrum St. Gallen, Vadianstrasse 26, 9001 St. Gallen, Switzerland a SpringerOpen Journal © 2014 König et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. Königet al. SpringerPlus2014,3:652 http://www.springerplus.com/content/3/1/652
on freestyle (Berthelot et al. 2012; Buhl et al. 2013b; Kollarz et al. 2013b; Wolfrum et al. 2013; Rüst et al. 2014). However, there was a large range of different athletic collectives examined in different time periods. For example, there were investigations about freestyle Olympic champions from 1896 to 1980 (Schulz and Curnow 1988) as aforementioned, elite freestyle swimmers during 1980–2009 (Berthelot et al. 2012), freestyle top ten US masters in freestyle in the time period of 1993–2002 (Fairbrother 2007a), and elite Swiss freestyle swimmers between 1994 and 2012 (Rüst et al. 2014). These different time periods might have had an influence on the outcome of the results, while the human species developed over time with changes in body dimensions such as body height, body mass and slenderness (Charles and Bejan 2009), and swimming performance increased continuously across the years (Charles and Bejan 2009; Stanula et al. 2012). Therefore, it is of particular importance to be aware of the different time periods in the various studies. Furthermore, it is of great importance to be aware of the methodology of what is analysed exactly. For example, there are a few longitudinal investigations analysing the individual’s peak performance (Pyne et al. 2004; Berthelot et al. 2012; Allen et al. 2014). That approach is different to what is examined in the present cross-sectional study. We intended to investigate the changes in the age of world class swimmers competing in specific competitions. For that reason, we investigated the age of finalists in the World Championships and the Olympic Games. In terms of the age of peak swimming performance, a few studies reported that there seemed to be a decrease in peak age with increasing race distance in freestyle (Schulz and Curnow 1988; Berthelot et al. 2012; Wolfrum et al. 2013), backstroke (Kollarz et al. 2013a), and individual medley (Buhl et al. 2013b). However, the opposite was found in running where younger athletes were faster in shorter (Schulz and Curnow 1988; Krzysztof and Mero 2013) and older athletes were faster in longer race distances (Trappe 2007; Leyk et al. 2009; Hoffman 2010; Knechtle et al.
al. 2012; Wolfrum et al. 2013), backstroke (Kollarz et al. 2013a), and individual medley (Buhl et al. 2013b). However, the opposite was found in running where younger athletes were faster in shorter (Schulz and Curnow 1988; Krzysztof and Mero 2013) and older athletes were faster in longer race distances (Trappe 2007; Leyk et al. 2009; Hoffman 2010; Knechtle et al. 2012). Furthermore, a difference in the age of peak swimming performance between the sexes was observed in several cross-sectional studies (Schulz and Curnow 1988; Rüst et al. 2012; Buhl et al. 2013b; Kollarz et al. 2013a; Vaso et al. 2013). Regarding the change in the age of peak performance in swimming, the age of peak swimming performance seemed to be stable over time (Schulz and Curnow 1988). Schulz and Curnow (1988) described the age of Olympic gold medal winners to be remarkably stable from 1896 to 1980. However, a wide range of different ages in peak freestyle swimming performance was reported in re- cent studies (Schulz and Curnow 1988; Tanaka and Seals 1997; Fairbrother 2007a, b; Berthelot et al. 2012; Buhl et al. 2013a; Kollarz et al. 2013b; Rüst et al. 2014; Allen et al. 2014; see also Tables 1 and 2). In addition, a difference in the age of peak swimming performance between athletes competing at national and international level was observed. For example, Kollarz et al. (2013b) showed in their cross-sectional analysis of elite free- style and backstroke swimmers competing between 1994 and 2011 that the age of peak swimming per- formance was more stable across the years for men competing in 50 m freestyle at international than at national level. Concerning the level of the investigated athletes, several studies examined the age of peak swimming performance in swimmers competing at national level and for specific swimming strokes such as freestyle (Tanaka and Seals 1997; Wolfrum et al. 2013; Buhl et al. 2013b; Donato et al. 2003; Rüst et al. 2014), breaststroke (Koch-Ziegenbein et al. 2013; Wolfrum et al. 2013), backstroke (Kollarz et al. 2013a, b), butterfly (Zingg et al. 2014b, c), and individual medley (Buhl et al.
swimmers competing at national level and for specific swimming strokes such as freestyle (Tanaka and Seals 1997; Wolfrum et al. 2013; Buhl et al. 2013b; Donato et al. 2003; Rüst et al. 2014), breaststroke (Koch-Ziegenbein et al. 2013; Wolfrum et al. 2013), backstroke (Kollarz et al. 2013a, b), butterfly (Zingg et al. 2014b, c), and individual medley (Buhl et al. 2013b; Vaso et al. 2013). However, the information about the age of peak swimming performance with its change is missing for swimmers competing at world class level. To date, the study from Schulz and Curnow (1988) was the first and only investigating the change in the age of peak swimming performance in athletes competing at world class level. However, Schulz and Curnow (1988) investigated only freestyle swimming and only Olympic winners. Nevertheless, to the best of our knowledge, no study examined to date the change of the age of peak swimming performance in all strokes and distances with data of athletes competing at world class level in very recent years out of one data set. Therefore, the aims of the present study were to investi- gate potential changes in the age of finalists competing in all strokes and all lengths at world class level such as the World Championships and the Olympic Games across recent years. For better comparability, all strokes and distances were included on condition that they were held in both World Championships and Olympic Games from 1994 to 2013 and 1992 to 2012, respectively. Based on Schulz and Curnow’s results (1988), it was hypothesised for all strokes and distances that (1) the age of finalists would remain stable over time for both women and men, and (2) swimming performance would increase across the years for both women and men. Materials and methods Ethics All procedures used in the study were approved by the Institutional Review Board of Kanton St. Gallen, Switzerland with a waiver of the requirement for informed consent of the participants given the fact that the study involved the analysis of publicly available data. Königet al. SpringerPlus2014,3:652 Page 2 of 13 http://www.springerplus.com/content/3/1/652
and men. Materials and methods Ethics All procedures used in the study were approved by the Institutional Review Board of Kanton St. Gallen, Switzerland with a waiver of the requirement for informed consent of the participants given the fact that the study involved the analysis of publicly available data. Königet al. SpringerPlus2014,3:652 Page 2 of 13 http://www.springerplus.com/content/3/1/652
Table 1 Studies investigating the age of peak swimming performance in women (yrs) Reference Freestyle Breaststroke Backstroke Butterfly Medley ♀50 m 100 m 200 m 400 m 800 m 1,500 m 100 m 200 m 100 m 200 m 100 m 200 m 200 m 400 m National Buhl et al.2013b19.3 18.618.2 18.6 Kollarz et al.2013b*19–20 18–21 19–20 18–20 18 Rüst et al.2014* 18.9–20.4 19.1 19.3 18.7 18.5 18.1–25.0 Wolfrum et al.201320–21 20–21 20–21 18–19 18–19 Zingg et al.2014c*19182018–20 18–20 International Allen et al.201426.1 24.2 22.3 22.3 21.9 22.2 23.7 22.6 21.9 23.1 22.0 21.7 21.4 Buhl et al.2013b19.3 20.318.2 20.8 Kollarz et al.2013b*20–25 20–24 19–21 21–22 19–21 Schulz and Curnow1988*18–20 17–18 16 Wolfrum et al.201326–27 24–25 22–23 22–23 22–23 *Studies investigating the change in the age of peak swimming performance. Königet al. SpringerPlus2014,3:652 Page 3 of 13 http://www.springerplus.com/content/3/1/652
Table 2 Studies investigating the age of peak swimming performance in men (yrs) Reference Freestyle Breaststroke Backstroke Butterfly Medley ♂50 m 100 m 200 m 400 m 800 m 1500 m 100 m 200 m 100 m 200 m 100 m 200 m 200 m 400 m National Buhl et al.2013b21.4 20.321.1 20.8 Kollarz et al.2013b*22–23 22–23 21–22 21–22 21 Rüst et al.2014* 23 22.5 21.4 20.3 20.3 20.3 Wolfrum et al.201326–27 22–23 22–23 18–19 16–17 Zingg et al.2014c*22232223 21 International Allen et al.201425.9 25.3 23.6 22.9 22.9 25.2 24.1 24.5 25.2 24.0 24.3 24.8 22.7 Buhl et al.2013b21.4 18.621.1 18.6 Kollarz et al.2013b*23–25 23–24 22–24 24 23 Schulz and Curnow1988*21–22 19–20 19–21 Wolfrum et al.201328–29 28–29 22–23 26–27 20–21 *Studies investigating the change in the age of peak swimming performance. Königet al. SpringerPlus2014,3:652 Page 4 of 13 http://www.springerplus.com/content/3/1/652
Data sampling It was intended to collect current data of female and male finalists from recent years. All data for this study were obtained from the world’s swimming ranking (www.swimrankings.net). This web page records all swimming race results according to events such as World Championships and Olympic Games. We started data collection from the year 1992 because previous data seemed not complete for all strokes and distances. Full data were available since 1992 for 991 female and 1,008 male performances (1,999 performances in total) in the World Championships and 624 female and 672 male performances (1,296 performances in total) in the Olympic Games. Regarding the World Championships, there was a difference of 17 performances between women and men due to the missing 1,500 m freestyle in women before 2001 and because of one female swimmer who was disqualified in 400 m individual medley at the World Championship in 2001. In the Olympic Games, there was a difference of 48 performances between both sexes due to the missing races in 1,500 m freestyle during the whole period. All races which were held in both the World Championships (1994–2013) and the Olympic Games (1992–2012) were included. Therefore, we excluded 50 m breaststroke, 50 m backstroke, and 50 m butterfly which were only held in the World Championships. The following races were included and analysed: Freestyle (50 m, 100 m, 200 m, 400 m, 800 m, and 1,500 m), breaststroke (100 m, 200m), backstroke (100 m, 200 m), butterfly (100 m, 200 m), and individual medley (200 m, 400 m). We analysed all listed strokes and distances in both sexes and in both the World Championships and the Olympic Games for changes in the age and swimming performance of all finalists over the years. The following numbers of finals were analysed: In the World Championships, 18 finals were analysed in freestyle for 50 m, 100 m, 200 m, 400 m, and 800 m (nine finals in both women and men for each distance). A total of 16 finals were analysed in 1,500 m freestyle (seven finals in women and nine finals in men).
years. The following numbers of finals were analysed: In the World Championships, 18 finals were analysed in freestyle for 50 m, 100 m, 200 m, 400 m, and 800 m (nine finals in both women and men for each distance). A total of 16 finals were analysed in 1,500 m freestyle (seven finals in women and nine finals in men). A total of 18 finals were analysed in 100 m and 200 m breaststroke, backstroke, and butterfly (nine finals in both women and men for each stroke and distance). In 200 m and 400 m individual medley 18 finals were analysed (nine finals in both women and men for both distances). In the Olympic Games, 12 finals were analysed in freestyle for 50 m, 100 m, 200 m, 400 m, and 800 m (six finals in both women and men for each distance). In 1,500 m freestyle, six finals were analysed (all of them in men). A total of 12 finals were analysed in 100 m and 200 m breaststroke, backstroke, and butterfly (six finals in both women and men for each stroke and distance). In 200 m and 400 m individual medley 12 finals were analysed (six finals in both women and men for both distances). This leads to a total of 412 finals with eight finalists in each (250 finals in the World Championships and 162 finals in the Olympic Games). The age of the athletes was calcu- lated from the year of birth given at the web page www.swimrankings.net. Statistical analysis Each final (i.e.set of 8 finalists) was tested for normal distribution and for homogeneity of variances prior to statistical analyses. Normal distribution was tested using a D’Agostino and Pearson omnibus normality test and homo- geneity of variances was tested using a Levene’s test. Data in the text and in the tables are given as mean ± standard devi- ation (SD). Following Hopkins et al. (2009), we calculated theeffectsizeofchangesinageandswimmingperformance since the use of ap-value provides no information about the direction or the size of the effect. Since all data were normally distributed, Pearson correlation analysis was used
variances was tested using a Levene’s test. Data in the text and in the tables are given as mean ± standard devi- ation (SD). Following Hopkins et al. (2009), we calculated theeffectsizeofchangesinageandswimmingperformance since the use of ap-value provides no information about the direction or the size of the effect. Since all data were normally distributed, Pearson correlation analysis was used to determine the slope of the change in age and swimming performance, respectively. To calculate effect sizes, we used the equation 2ffi rffiffiffiffiffiffiffi 1−r 2 pwhere effect sizes were classified as trivial (<0.2), small (0.2–0.6), moderate (0.6–1.2), large (1.2–2.0), very large (2.0–4.0) and extremely large (>4.0) following Hopkins (2006). Results Between 1992 and 2013, data were available for 3,295 performances, including 1,615 female (49%) and 1,680 male (51%) performances. These performances are divided into 1,999 in the World Championships and 1,296 in the Olympic Games. Changes in the age of finalists In the World Championships, the age of the finalists increased for all strokes and distances with the exception of 200 m backstroke in women, 400 m freestyle in men and 200 m breaststroke in men where the age of the finalists decreased (Table 3). The magnitudes of the effects were trivial for 200 m backstroke men, small for 200 m freestyle women, 100 m backstroke women, 100 m and 400 m freestyle men, 200 m breaststroke men, and 400 m medley men, moderate for 50 m and 100 m freestyle women, 200 m backstroke women, 400 m medley women, and 200 m medley men, large for 100 m breaststroke women, 200 m backstroke women, 200 m freestyle men, very large for 400 m and 800 m freestyle women, 100 m and 200 m butterfly women, 50 m and 1500 m freestyle men, 100 m breaststroke men, 100 m backstroke men, 200 m butterfly men, and extremely large for 1500 m freestyle women, 200 m breaststroke women, 200 m medley women, 800 m freestyle men, and 100 m butterfly men. Königet al. SpringerPlus2014,3:652 Page 5 of 13 http://www.springerplus.com/content/3/1/652
Description
The study analyzes age and performance trends in elite swimmers over two decades.