Masters sport has its roots in the 1970's where it became an alternative to mainstream sports (i.e., youth and elite sports). Prior to this, elderly people were excluded from organized sport, mainly due to two social norms. Firstly, sport used to be a form to build the character of a person and was therefore addressed to young people. Secondly, sport was considered to cause serious harm to the body of elderly (Coakley, 2017). The increasing popularity of masters sports over the past 40 years has been reflected by increases in participation rates at major masters competitions throughout the world (Knechtle et al., 2016; 2017; Nikolaidis et al., 2017; Unterweger et al., 2016).
Masters athletes have a variety of motives to participate in sports throughout their lifetime, such as health and fitness reasons, enjoyment of physical activity, opportunities to test their own physical capabilities, social inclusion, as well as extrinsic reasons, like awards (Hodge et al., 2008; Larson et al., 2019; Medic, 2009). In most masters competitions, sport governing organizations arrange 5-year competitive age categories (e.g., athletics, swimming) to provide equal chances for aging athletes and organize competitions which cater to their needs to increase the participation of middle-aged and elderly in sports (Medic et al., 2009a). However, recent studies have suggested that there may be potential problems with the current age categorization, indicating that a constituent year effect may be influencing the motivation, participation, and performance of athletes in masters swimming and track and field (Medic et al., 2009a).
The constituent year effect in masters sport refers to the participation- and performance--related advantage of being relatively younger within a standard 5-year age category bracket (Medic et al., 2007). Medic et al. (2007) examined athletes from US masters track-and-field and swimming and found that there was a higher percentage of athletes participating in the National championships when they were in the first and second year of an age group, and significantly fewer if they were in the fourth or fifth year. Medic et al. (2009a) provided further evidence of a participation-related constituent year effect in both male and female masters athletes and in athletes in the fourth decade of life and beyond, however the effect was stronger in males than females and that it increased with age. Participation-related constituent year effect was also found in a sample of US marathon runners (Connick et al., 2015) and Australian masters track and field athletes (Medic et al., 2018). Medic et al. (2009b) also found participation-related constituent year effect in masters swimming and track and field; however the effect was not significant in masters weightlifting and rowing potentially because those sports are grouped based on both age and weight class and/or due to the lower popularity and cultural importance of these sports. Utilizing a retrospective longitudinal study design where athletes were followed over a period of 5 years, Medic et al. (2011) reported that the odds of a masters swimmer participating in the first year of any 5-year age category was more than two times greater than the odds of that athlete participating during the fifth year.
Further research is necessary to better understand constituent year effect in masters sports as this might help to create an environment in which aging athletes have better opportunities to participate successfully in sports. So far, no studies have reported whether there are changes or significant points in history regarding the constituent year effect throughout the 40+ years of masters sports (Rubin & Rahe, 2010). For example, studies by Medic et al. (2007, 2009a) were cross sectional in nature in that participation entries that were collected between 1998 and 2006 were grouped and converged into one database. Thus, it remains unknown whether there has always been a participation-related constituent year effect in masters sports or if there has been a change, development or peak in the strength of the effect. Therefore, the main research questions examined in this study were: Has the participation-related constituent year effect always existed in US masters swimming? Has the strength or direction of the effect changed over time? Has the effect been influenced by gender and age over time?
The present study tracked the existence of the constituent year effect in masters athletes participating in the US Masters national short course swimming championships at each of the historical time periods in years 1972, 1982, 1992, 2002, 2012 and 2016. A time span of ten years in between the examined competitions was used in order to examine representative data on the development of constituent year effect, with the year 2016 representing the most recent year (i.e., essential data from 2017, 2018, and 2019 competitions were unavailable). Archived data were retrieved from the official homepage of the US Masters Swimming (i.e., http://www.usms.org). Data were considered reliable since they were posted as the 'final and official' meet roster by the overriding national body for the sport of swimming (i.e., US Masters Swimming). Even though athletes 18 years of age or older are eligible to participate in masters swimming, the data taken into consideration for analyses only included swimmers of the age 35 and older. The approach was chosen since it is in line with previous studies on constituent year effect in masters sports (Medic et al., 2007) and thus allows for congruency and comparability. The sport of masters swimming was chosen since it is one of the sports in which the participation-related constituent year effect had been documented. Data on participating athletes for each of the six selected historical periods were recorded from the result lists along with the name, age and gender of each athlete with the total sample consisting of 5232 masters athletes (3220 males and 2012 females; age range 35 to 95 years).
Since the establishment of US masters swimming in 1970, National Short Course Masters Swimming...