Abstract
kground:The purpose of this study was to examine the sex and age-related differences in performance in a draft-legal ultra-cycling event. Methods:Age-related changes in performance across years were investigated in the 24-hour draft-legal cycling event held in Schötz, Switzerland, between 2000 and 2011 using multi-level regression analyses including age, repeated participation and environmental temperatures as co-variables. Results:For all finishers, the age of peak cycling performance decreased significantly (β=−0.273, p = 0.036) from 38 ± 10 to 35 ± 6 years in females but remained unchanged (β=−0.035,p= 0.906) at 41.0 ± 10.3 years in males. For the annual fastest females and males, the age of peak cycling performance remained unchanged at 37.3 ± 8.5 and 38.3 ± 5.4 years, respectively. For all female and male finishers, males improved significantly (β= 7.010,p= 0.006) the cycling distance from 497.8 ± 219.6 km to 546.7 ± 205.0 km whereas females (β=−0.085,p= 0.987) showed an unchanged performance of 593.7 ± 132.3 km. The mean cycling distance achieved by the male winners of 960.5 ± 51.9 km was significantly (p<0.001) greater than the distance covered by the female winners with 769.7 ± 65.7 km but was not different between the sexes (p> 0.05). The sex difference in performance for the annual winners of 19.7 ± 7.8% remained unchanged across years (p> 0.05). The achieved cycling distance decreased in a curvilinear manner with advancing age. There was a significant age effect (F = 28.4,p<0.0001) for cycling performance where the fastest cyclists were in age group 35–39 years. Conclusion:In this 24-h cycling draft-legal event, performance in females remained unchanged while their age of peak cycling performance decreased and performance in males improved while their age of peak cycling performance remained unchanged. The annual fastest females and males were 37.3 ± 8.5 and 38.3 ± 5.4 years old, respectively. The sex difference for the fastest finishers was ~20%.
years. Conclusion:In this 24-h cycling draft-legal event, performance in females remained unchanged while their age of peak cycling performance decreased and performance in males improved while their age of peak cycling performance remained unchanged. The annual fastest females and males were 37.3 ± 8.5 and 38.3 ± 5.4 years old, respectively. The sex difference for the fastest finishers was ~20%. It seems that women were not able to profit from drafting to improve their ultra-cycling performance. Keywords:Cycling, Master athletes, Sex difference, Ultra-endurance * Correspondence:beat.knechtle@hispeed.ch 1 Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland 2 Gesundheitszentrum St. Gallen, St. Gallen, Switzerland Full list of author information is available at the end of the article © 2014 Pozzi et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Pozziet al. BMC Sports Science, Medicine, and Rehabilitation2014,6:19 http://biomedcentral.com/2052-1847/6/19
Background The most traditional endurance and ultra-endurance sports are swimming, cycling, running, and triathlon as a combination of them. In recent years, several studies re- ported an increased participation in ultra-endurance per- formances−defined as an endurance performance of six hours and longer [1]−such as ultra-running [2-4], ultra- cycling [5-8] and ultra-triathlon [9,10]. For several of these ultra-endurance events, an increased participation and an improvement in performance of master athletes older than 35 years [11] have been observed [5,12-14]. Several recent studies analysed also the influence of age and sex on triathlon performance [9,15-17]. There were also studies focusing on the influence of age and sex on running performance [18-20], however, only a few studies investigated other endurance disciplines such as swim- ming [21,22] or cycling [23,24]. Cycling as a non-weight- bearing activity represents an interesting model because it can be performed even in older ages [7] because of its non-technical and its non-weight-bearing character [25]. Age has been reported as an important predictor variable in ultra-endurance athletes such as ultra-marathoners [26]. An age-related decline in endurance performance is inevit- able even if master athletes tend nowadays to improve their performance [12,13,18]. Endurance performance starts to decline after the age of ~55 years independently of the physical activity [25]. However, there seemed to be dif- ferences in the age-related performance decline regarding the different endurance disciplines. Ransdellet al.demon- strated that the age-related decline in endurance perform- ance was exponential after the age of ~55 years for both sexes in swimming, cycling and running [25]. However, the age-related decline was less pronounced in swimming and cycling compared to running when master competitors in running, swimming and cycling were investigated [25]. For triathletes, Bernardet al.[27] and Leperset al.[28] showed a less pronounced age-related decline in endurance per- formance in cycling compared to running and swimming. In contrast to Ransdellet al.[25], Baker and Tang [29] re- ported for sprint cycling that female and male master rec- ord performances decreased with advancing age in a similar manner as for swimming, rowing, weightlifting, tri- athlon and running. Balmeret al.[23] showed that cycling performance declined in an
decline in endurance per- formance in cycling compared to running and swimming. In contrast to Ransdellet al.[25], Baker and Tang [29] re- ported for sprint cycling that female and male master rec- ord performances decreased with advancing age in a similar manner as for swimming, rowing, weightlifting, tri- athlon and running. Balmeret al.[23] showed that cycling performance declined in an indoor 16.1-km time-trial with increasing age. Apart from the age-related performance decline, the age at which peak performance is achieved would be of inter- est for endurance athletes such as cyclists to plan their career. Cycling races can be held without drafting such as cycling time trials [30], mountain bike cycling races [31], ultra-endurance cycling races [7,8] or cycling time trials in long-distance triathlons [9,15], or with drafting such as traditional road cycling races. Regarding ultra-cycling, a recent study investigating the age trends from 2001 to 2012 in a 720 km ultra-cycling race reported that the fast- est female and male performance was achieved at the age of 35.9 ± 9.6 and 38.7 ± 7.8 years, respectively [7]. In a 120 km mountain bike cycling race held between 1994 and 2012, the age of the fastest athletes was lower than in a 720 km ultra-cycling race where the fastest females achieved the fastest race times at the age of 30.7 ± 5.0 years and males at the age of 27.1 ± 3.4 years [31]. These recent studies investigating performance in ultra- cycling used data from races where drafting was forbid- den such as the 120 km mountain bike ultra-cycling race‘Swiss Bike Master’[31], the 720 km‘Swiss Cycling Marathon’as a qualifier for the‘Race across America’ (RAAM) [7], and the‘RAAM’itself [8]. These studies showed that the participation in females was low [5,31], the performance decreased in males compared to females [31] but improved in femalescompared to males [7] across years, and the sex difference in performance remained un- changed [8] or decreased [7,31]. The sex difference in per- formance for the fastest finishers was at ~20 ± 10% in these races [5,7,8]. Drafting during cycling permits reducing average power output, oxygen consumption (VO
performance decreased in males compared to females [31] but improved in femalescompared to males [7] across years, and the sex difference in performance remained un- changed [8] or decreased [7,31]. The sex difference in per- formance for the fastest finishers was at ~20 ± 10% in these races [5,7,8]. Drafting during cycling permits reducing average power output, oxygen consumption (VO 2) and heart rate and therefore to improve performance [32]. Furthermore, it re- sults in a reduction in frontal resistance and reduced energy cost at a given submaximal intensity [33]. However, no data exist about the age of peak ultra-cycling performance in a draft-legal cycling race in contrast to a non-drafting ultra- cycling performance [7]. Performance between females and males in a draft-legal ultra-cycling race might also be differ- ent as it has been shown for non-drafting ultra-cycling races [7]. Drafting might enhance female performance as it has been shown for ultra-swimming. For example, in the 34-km‘English Channel Swim’from Dover (Great Britain) to Calais (France) where athletes have to cover the distance alone, the fastest men were faster than the fastest women [34]. However, in the 46-km 'Manhattan Island Marathon Swim' where drafting is allowed, the best women were ~12- 14% faster than the best men [35]. To date, no study inves- tigated the age and sex of finishers in an ultra-cycling performance where drafting is allowed. If males and females were allowed to ride together with drafting, the sex differ- ence in cycling performance might be lower compared to non-drafting conditions. Theaimsofthestudyweretoinvestigatethepartici- pation trends, and the sex and age-related differences in performance in ultra-cycling in a 24-hour draft-legal ultra- endurance cycling event held in Schötz, Switzerland, be- tween 2000 and 2011. Considering existing findings in ultra-swimming, we hypothesized for a draft-legal cycling race that the sex difference in ultra-cycling performance would be lower compared to previous observations in ultra-endurance running or ultra-endurance cycling per- formance where drafting was not allowed. Pozziet al. BMC Sports Science, Medicine, and Rehabilitation2014,6:19 Page 2 of 12 http://biomedcentral.com/2052-1847/6/19
a draft-legal cycling race that the sex difference in ultra-cycling performance would be lower compared to previous observations in ultra-endurance running or ultra-endurance cycling per- formance where drafting was not allowed. Pozziet al. BMC Sports Science, Medicine, and Rehabilitation2014,6:19 Page 2 of 12 http://biomedcentral.com/2052-1847/6/19
Year Fin ishers 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 0 10 20 30 40 50 60 70 80 90 100 W om en Y = 0.09*X + 6.5; R 2 = 0.01; P > 0.05 Men Y = -2.6*X + 85.9; R 2 =0.46;P=0.02 A Age Groups (Years) Fin ishers <25 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 >64 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Women Men B Age Groups (Years) %ofFinishers <25 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 >64 0 5 10 15 20 25 C Women Men Figure 1Number of female and male finishers in the’24 Stunden Schötz’from 2000 to 2011 (Panel A), number of female and male finishers for each age group (Panel B) and number of finishers for each age group expressed in percent of all finishers (Panel C). Pozziet al. BMC Sports Science, Medicine, and Rehabilitation2014,6:19 Page 3 of 12 http://biomedcentral.com/2052-1847/6/19
Methods Ethics This study was approved by the Institutional Review Board of St. Gallen, Switzerland, with waiver of the re- quirement for informed consent given that the study in- volved the analysis of publicly available data. The race To test our hypothesis, the age at the time of the competi- tion and the achieved cycling distance (km) of all male and female solo riders at the 24-hours cycling race Schötz (‘24 Stunden Schötz’) were analysed from 2000 to 2011. Since 2000, the‘24 Stunden Schötz’has been held each year in the city of Schötz, Switzerland, in the first weekend of august. The last edition was held in 2011. Many athletes used this race to prepare for the‘Race Across AMerica’ (RAAM). Several winners of the‘24 Stunden Schötz’won later the‘RAAM’. The flat circuit extended over a distance of 9,888 m. In each lap, the athletes had to overcome 35 m difference in altitude. Solo and team riders were competing in the same field. The laps were counted elec- tronically, drafting was allowed and solo riders were gen- erally drafting behind team riders. The athletes had the opportunity to be assisted during the race by a personal support crew. Data collection and data analysis The data set from this study was obtained from the race website of the‘24 Stunden Schötz’(www.24stundenren- nen.ch) and from the race director for data of earlier years where the age of the athletes was missing. Be- tween 2000 and 2011, a total of 916 finishers (i.e.83 fe- males and 833 males) completed the race. The 24-hour cycling performance was expressed in km. The age at the time of the competition and the cycling perfor- mances of all male and female competitors were ana- lysed from 2000 to 2011. The magnitude of the sex difference was examined by calculating the percent dif- ference between the female and male winner for each year. The effect of age on the 24-hour cycling perform- ance was only analysed in males because the number of female finishers in the different age groups was too small for an accurate data analysis (Figure 1A). Because the age
of the sex difference was examined by calculating the percent dif- ference between the female and male winner for each year. The effect of age on the 24-hour cycling perform- ance was only analysed in males because the number of female finishers in the different age groups was too small for an accurate data analysis (Figure 1A). Because the age of both the annual male winners and all annual male finishers did not significantly change across the years, we pooled the data of the 12 years for the ten fast- est males for each age group. The age groups distin- guish the categories for each period of 5 years as follows: < 25 years, 25–29 years, 30–34 years, 35–39 years, 40–44 years, 45–49 years, 50–54 years, 55–59 years, and 60–64 years. Therefore, the best top ten per- formances of the athletes in nine age groups during the studiedperiodwereconsidered. Statistical analyses Each set of data was tested for normal distribution using D’Agostino and Pearson omnibus normality test and for homogeneity of variances using Levene’stest prior to statistical analyses. Trends in participation were analysed using linear regression whereas results were tested for linearity with run’s test. Single and multi-level regression analyses were used to investigate changes in performance and age of the finishers. A hierarchical regression model avoided the impact of a cluster-effect on results where a particular athlete fin- ished more than once. Regression analyses of perform- ance were corrected for age of athletes to prevent a misinterpretation of the‘age-effect’as a‘time-effect’ since age is an important predictor variable in ultra- endurance performance [26]. Regression models were also corrected with environmental temperatures (i.e. lowest and the highest temperature during every race) since environmental conditions such as extreme heat impairs endurance [30,36] and ultra-endurance per- formance [37,38]. Historical weather data with air temperature for this analysis were provided by“MeteoSch- weiz”(www.meteoschweiz.admin.ch) (Table 1). The per- formance of the top ten athletes per age group were compared to the performance of the fastest age group using one-way analysis of variance (ANOVA) with Dunnett post-hoc analysis. Statistical analyses were performed using IBM SPSS Statistics (Version 22,
ultra-endurance per- formance [37,38]. Historical weather data with air temperature for this analysis were provided by“MeteoSch- weiz”(www.meteoschweiz.admin.ch) (Table 1). The per- formance of the top ten athletes per age group were compared to the performance of the fastest age group using one-way analysis of variance (ANOVA) with Dunnett post-hoc analysis. Statistical analyses were performed using IBM SPSS Statistics (Version 22, IBM SPSS, Chicago, IL, USA) and GraphPad Prism (Version 6.01, GraphPad Software, La Jolla, CA, USA). Signifi- cance was accepted atp<0.05 (two-sided fort-tests). Data in the text and figures are given as mean ± stand- ard deviation (SD). Table 1 Daily maximum (T max) and daily minimum (T min) temperatures on race days Year T max (°C) T min (°C) 2000 20 18 2001 27 20 2002 20 17 2003 29 21 2004 26 18 2005 22 16 2006 15 10 2007 24 16 2008 25 19 2009 22 15 2010 20 16 2011 19 15 Weather data were acquired from‘MeteoSchweiz’(www.meteoschweiz.admin.ch). Pozziet al. BMC Sports Science, Medicine, and Rehabilitation2014,6:19 Page 4 of 12 http://biomedcentral.com/2052-1847/6/19
Results Participation trends and age groups A total of 916 finishers (i.e.83 females and 833 males) com- pleted the race between 2000 and 2011. The annual num- ber of finishers over the history of the event is shown in Figure 1A. The annual number of males decreased across years whereas the annual number of females remained unchanged. Between 2000 and 2011, the annual number of finishers was 70 ± 14 (range: 44–88) for males and 7 ± 2 (range: 4–11) for females, respectively. Females accounted on average for 9.2 ± 3.0% of the field over the 12-years period. The age distribution of both female and male fin- ishers during the 12-years period is displayed in Figure 1B. Mostofthemalefinisherswererankedinagegroup35–39 Year A g e O f F in ishe rs (Y e a rs) 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 20 25 30 35 40 45 50 55 60 Women Men A Year A ge O f W inners (Y ears) 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 20 25 30 35 40 45 50 55 60 B Figure 2Changes in the age of all female and male finishers (Panel A) and for the annual winners (Panel B) in the‘24 Stunden Schötz’ from 2000 to 2011. Pozziet al. BMC Sports Science, Medicine, and Rehabilitation2014,6:19 Page 5 of 12 http://biomedcentral.com/2052-1847/6/19
years whereas most of the female finishers were in the age groups 25–29 and 35–39 years. Cyclists older than 40 years of age represented ~53% of the male and ~35% of the fe- male finishers. Expressed in percent of all finishers, most of the male finishers were ranked in age group 25–29 years and most of the female finishers in age group 35–39 years (Figure 1C). The age of the cyclists The age of the finishers for each sex is shown in Figure 2A for all annual female and male finishers and in Figure 2B for annual female and male winners. For all female and male annual finishers, the age of peak cycling performance decreased significantly in females from 38 ± 10 years (2000) to 35 ± 6 years (2011) (Table 2). In males, however, the age of peak cycling performance remained unchanged at 41.0 ± 10.3 years (Table 2). For the annual fastest fe- males and males, the age of peak cycling performance remained unchanged at 37.3 ± 8.5 and 38.3 ± 5.4 years, respectively. The performance of the cyclists The achieved cycling distance (km) of all finishers for both sexes is presented in Figure 3A and for the annual winners in Figure 3B. Overall males improved their cycling distance significantly from 497.8 ± 219.6 km (2000) to 546.7 ± 205.0 km (2011) whereas overall females showed an un- changed performance over time of 593.7 ± 132.3 km (Table 3). The mean cycling distance covered by the male winners (960.5 ± 51.9 km) was significantly (p<0.001) greater than the mean distance covered by the female win- ners (769.7 ± 65.7 km) (Figure 3B) but did not significantly change across the years for both sexes (Table 3). The sex difference in cycling performance The sex difference in cycling performance for the winners during the 2000–2011 period is shown in Figure 4. The mean sex difference was 19.7 ± 7.8% (range: 7.7-33.0%) and did not significantly change across years (Table 4). The age-related changes in male cycling performances The mean age-related change for the achieved cycling distance in the ten fastest
Description
This research analyzes performance trends in a 24-hour ultra-cycling event from 2000 to 2011.