Lisa Müller

The role of a relative age effect in the first winter Youth Olympic Games in 2012

Background Owing to the separation into age groups at the first winter Youth Olympic Games (YOG), athletes differed in age by up to two years, leading to a potential relative age effect (RAE). Objective The purpose of this study was to define the role of the RAE in the first winter YOG with regard to sex, type of sport and performance. Methods The birth dates and anthropometric data of all 1021 athletes (557 male, 464 female, 14–19 years old) participating in 15 sports were analysed. A χ2 test was used to assess the difference between the observed and expected birth distributions. ANOVA (analysis of variance) and Kruskal−Wallis analyses were used to investigate differences in anthropometrics. Results The birth date distribution of the overall sample was significantly different from an equal distribution, with an over-representation of athletes born shortly after the cut-off date (χ2=284.7, p<0.001). A significant RAE was found in both male (χ2=245.1, p<0.001) and female competitors (χ2=74.6, p<0.001). An analysis based on the type of sport showed an RAE in all categories (strength—χ2=229.9, p<0.001, endurance—χ2=60.4, p<0.001 and technique-related sports χ2=25.2, p=0.001). Relatively older competitors were also over-represented among medal winners (χ2=47.9, p<0.001). Relatively older male competitors were significantly taller (p=0.005) and heavier (p<0.001) than younger competitors. No differences were found in female competitors. Conclusions The results suggest that relative age had a highly significant influence on participation in various sports regardless of sex. A possible strategy to reduce the RAE would be a fixed quota for each birth year within the two-year age group across events.

The Role of a Relative Age Effect in the 12th Winter European Youth Olympic Festival in 2015

The aim of this study was to define the role of the relative age effect in the 12th Winter European Youth Olympic Festival 2015. The birth dates of all 899 participants and anthropometric data of 655 participants were analyzed. A significant relative age effect was present in the total sample and among the male athletes but not in the female athletes. Additionally, a significant relative age effect was present in strength- and endurance-related sports but not in technique-related sports. Statistically significantly more older athletes won medals. Relative age had a strong influence on participation in strength- and endurance-related sports as well as on performance.

Biological Maturity Status Strongly Intensifies the Relative Age Effect in Alpine Ski Racing.

The relative age effect (RAE) is a well-documented phenomenon in youth sports. This effect exists when the relative age quarter distribution of selected athletes shows a biased distribution with an over-representation of relatively older athletes. In alpine ski racing, it exists in all age categories (national youth levels up to World Cup). Studies so far could demonstrate that selected ski racers are relatively older, taller and heavier. It could be hypothesized that relatively younger athletes nearly only have a chance for selection if they are early maturing. However, surprisingly this influence of the biological maturity status on the RAE could not be proven, yet. Therefore, the aim of the present study was to investigate the influence of the biological maturity status on the RAE in dependence of the level of competition. The study investigated 372 elite youth ski racers: 234 provincial ski racers (P-SR; high level of competition) and 137 national ski racers (N-SR; very high level of competition). Anthropometric characteristics were measured to calculate the age at peak height velocity (APHV) as an indicator of the biological maturity status. A significant RAE was present among both P-SR and N-SR, with a larger effect size among the latter group. The N-SR significantly differed in APHV from the P-SR. The distribution of normal, early and late maturing athletes significantly differed from the expected normal distribution among the N-SR, not among the P-SR. Hardly any late maturing N-SR were present; 41.7% of the male and 34% of the female N-SR of the last relative age quarter were early maturing. These findings clearly demonstrate the significant influence of the biological maturity status on the selection process of youth alpine ski racing in dependence of the level of competition. Relatively younger athletes seem to have a chance of selection only if they are early maturing.

The Relationship between Physical Motor Skills, Gender and Relative Age Effects in Young Austrian Alpine Ski Racers

The Relative Age Effect (RAE) refers to an over-representation of athletes born early in a selection year. The aims of this study were twofold: to test the presence of RAE depending on the gender and age in young alpine ski racers, and to test the influence of the level of physical motor skills on RAE. We investigated 989 participants of the entrance exams of three Austrian ski boarding schools, examined their birth dates and tested three different physical fitness abilities. Chi2-tests revealed significant RAEs for the total sample (χ2=23.81; p<0.001**), as well as for participants of both genders, children aged 9–10 and adolescents aged 14–15 years. No gender or age specific differences were shown in relation to the extent of the RAE. The results indicate that the level of the tested physical motor skills does not influence the RAE. The selection at the entrance exams did not reveal RAEs; consequently, a substantial portion of the selection of relatively older athletes in the talent selection process has been completed before the entrance into a ski boarding school.

Influential Factors on the Relative Age Effect in Alpine Ski Racing.

The relative age effect (RAE), which refers to an over-representation of selected athletes born early in the selection year, was proven to be present in alpine ski racing in all age categories at both national and international levels. However, the influential factors on, or the causal mechanisms of, the RAE are still unknown. Therefore, the aim of the present study was to examine three possible influential factors on the relative age effect in alpine skiing: physical performance, anthropometric characteristics and biological maturational status. The study included the investigation of 282 elite Austrian youth ski racers and 413 non-athletes (comparison group) of the same age (10–13 years) and region. Six physical performance tests were performed, body mass and height were assessed, and the age at peak height velocity (APHV) was calculated. A significant RAE was present in the ski racers. No differences were shown in the physical performance characteristics or in the calculated APHV between the relative age quarters. These results suggest that ski racers born in the last quarter can counteract the relative age disadvantages if they already present the same level of physical performance and maturational status as those born at the beginning of the year. The height and weight of ski racers born at the beginning of the year were significantly higher compared to the non-athletes, and ski racers born in relative age quarter 1 were taller and heavier compared to the ski racers of the other quarters. This indicates that the anthropometric characteristics influence the selection process in alpine ski racing, and that relatively older athletes are more likely to be selected if they exhibit advanced anthropometric characteristics.

Identifying talented track and field athletes: The impact of relative age effect on selection to the Spanish National Athletics Federation training camps

ABSTRACT This study examined the impact of relative age effect (RAE) on selection to the Spanish National Athletics Federation (RFEA) training camps (TC) between 2006 and 2013. Overall, 1,334 selected athletes at U15 years (cadet) and U17 years (juvenile) were compared against 27,711 licensed but unselected athletes for the same age groups. The results highlighted the influential role of the RAE on selection to national level track and field training camp opportunities. Interestingly, this effect was mediated by age and gender, where effects were stronger for both males and younger athletes (U15), with no evidence of RAE for older (U17) female athletes. These results support the “maturation-selection” hypothesis as a mechanism for RAE. Particularly given the long-term goals of RFEA (e.g., production of successful senior elite athletes), these results highlight the need to consider the impact of current selection processes on effective provision of opportunities to those athletes with most potential to succeed in the long term. A number of possible context-relevant solutions are discussed, including education and awareness raising, using holistic selection criteria and correction adjustments techniques.

A Novel Device to Preserve Physical Activities of Daily Living in Healthy Older People.

OBJECTIVE To determine the effectiveness of exercise in improving sensorimotor function and functional performance, crucial parts of activities of daily living in healthy older adults. DESIGN RCT. SETTING Laboratory. PARTICIPANTS 39 subjects (M = 71.8 years, range: 61-89 years). INTERVENTION Task-oriented visual feedback balance training. PRIMARY OUTCOME MEASURE Timed Up & Go (TUG). SECONDARY OUTCOME MEASURES Chair stand test (CST), self-paced walk test, maximum isometric torque, quiet stand posturography, and dynamic balance (DB). RESULTS Postintervention comparison of the treatment group (TG) and control group (CG) showed better TUG (p < .01), CST (p < .001), and DB (p < .025) for the TG. Pre-post intervention comparison of the TG showed better clinically-relevant outcomes in TUG (p < .001), CST (p < .001), and DB (p < .001). CONCLUSION Active driven visual feedback balance training is effective in improving functional performance and dynamic balance in older adults.

Injuries and illnesses in a cohort of elite youth alpine ski racers and the influence of biological maturity and relative age: a two-season prospective study

Background Studies on injuries and illnesses involving youth ski racers younger than 15 years are lacking in the literature. The aim of this study was prospectively to assess the incidence, prevalence, and severity of traumatic and overuse injuries, as well as illnesses of elite youth ski racers with regard to sex, biological maturity status, and relative age. Subjects and methods A prospective, longitudinal cohort design was used to monitor the anthropometrics, training characteristics, traumatic and overuse injuries, and illnesses of 82 elite youth ski racers (51 males, 31 females, age 9–14 years) over 2 consecutive years. The exact training exposure (skiing and athletic) was recorded. Relative age and estimated biological maturity status were assessed. Results Relatively low injury incidence or prevalence (traumatic, 0.86/1,000 hours of training; overuse, 0.28/1,000 hours) and comparably high illness prevalence (2.4/athlete) were reported. The knee was the most commonly affected body part (traumatic injuries 36.5%, overuse injuries 82%). A high number of bone fractures were revealed (46%), while no stress fractures occurred; 66% of the illnesses were respiratory tract infections. No differences were found between males and females, the differing maturity groups, or relative age quartiles. Early-maturing athletes had comparably low traumatic and overuse-injury rates. Relatively younger athletes had low traumatic injury rates. Conclusion The injury-prevention measures implemented in the training process of youth ski racers seem to contribute to a low incidence of injury. Biological maturity status should be considered in the training process to prevent injuries in late-maturing athletes.

Relative age effects in international age group championships: A study of Spanish track and field athletes

The relative age effect is a well-researched phenomenon, however there is still a dearth of understanding in track and field and female sport. This study investigated the role of relative age on selection for international competition of Spanish age group athletes between 2006–2014. Six hundred and forty two athletes competed for Spain at U20 or U18 age group international competition (n = 359 males; 283 females) across 9 years. The birthdates of these athletes were compared against the population of registered athletes at that time (14,502 males; 10,096 females). The results highlighted the influential role of relative age on selection to these opportunities. In line with previous research, this effect was mediated by age and gender, with stronger effects for both males and younger athletes (U18). The data best supported the ‘maturation-selection’ hypothesis as a mechanism for RAEs. These results highlight the need to carefully consider the role and need for international competitive opportunities at different age groups. A number of possible context relevant solutions are discussed, including correction adjustments techniques and competition structure within track and field.

Long-Term Athletic Development in Youth Alpine Ski Racing: The Effect of Physical Fitness, Ski Racing Technique, Anthropometrics and Biological Maturity Status on Injuries

Alpine ski racing is known to be a sport with a high risk of injuries. Because most studies have focused mainly on top-level athletes and on traumatic injuries, limited research exists about injury risk factors among youth ski racers. The aim of this study was to determine the intrinsic risk factors (anthropometrics, biological maturity, physical fitness, racing technique) for injury among youth alpine ski racers. Study participants were 81 youth ski racers attending a ski boarding school (50 males, 31 females; 9–14 years). A prospective longitudinal cohort design was used to monitor sports-related risk factors over two seasons and traumatic (TI) and overuse injuries (OI). At the beginning of the study, anthropometric characteristics (body height, body weight, sitting height, body mass index); biological maturity [status age at peak height velocity (APHV)]; physical performance parameters related to jump coordination, maximal leg and core strength, explosive and reactive strength, balance and endurance; and ski racing technique were assessed. Z score transformations normalized the age groups. Multivariate binary logistic regression (dependent variable: injury yes/no) and multivariate linear regression analyses (dependent variable: injury severity in total days of absence from training) were calculated. T-tests and multivariate analyses of variance were used to reveal differences between injured and non-injured athletes and between injury severity groups. The level of significance was set to p < 0.05. Relatively low rates of injuries were reported for both traumatic (0.63 TI/athlete) and overuse injuries (0.21 OI/athlete). Athletes with higher body weight, body height, and sitting height; lower APHV values; better core flexion strength; smaller core flexion:extension strength ratio; shorter drop jump contact time; and higher drop jump reactive strength index were at a lower injury risk or more vulnerable for fewer days of absence from training. However, significant differences between injured and non-injured athletes were only observed with respect to the drop jump reactive strength index. Regular documentation of anthropometric characteristics, biological maturity and physical fitness parameters is crucial to help to prevent injury in youth ski racing. The present findings suggest that neuromuscular training should be incorporated into the training regimen of youth ski racers to prevent injuries.