Relative Age Effect Among the Best Norwegian Track and Field Athletes of All Time: Comparisons of Explosive and Endurance Events.

The purpose of this study was to investigate the degree of relative age effect (RAE) among the best Norwegian track and field athletes of all time, aged 13 years to senior, as well as to investigate the differences between athletes in events that impose different demands on their physical characteristics, categorised in endurance and explosiveness. The degree of RAE was investigated by examining the difference between the sample's (N = 21,711) quarterly birth distribution and the quarterly distribution of birth of the Norwegian population as a whole from 1966 to 2019. To determine whether or not an RAE was present, chi-square tests (χ2) were conducted against an even distribution, with Cramer's V (phi or ɸ) as a measure of effect size. The study's results show a strong RAE in the two youngest age groups in both genders. RAE decreases with increasing age, but the effect is still present at the senior level in both men and women. Furthermore, the degree of RAE was strongest in explosive events in both boys (ɸ = 0.46) and girls (ɸ = 0.30), while in endurance events it was strong in boys (ɸ = 0.38) but not in girls (ɸ = 0.13). Prominent effect of RAE in the 13- and 14-year-old classes can be explained by the fact that in the youngest age groups impose the highest relative age difference. In addition, this is an age group where there are large differences in growth spurts, physical characteristics and training experience. Elimination of RAE with increasing age may be due to the fact that after puberty inherent physical advantages as a result of the month of birth are evened out. The prominent RAE in explosive events and in boys may be due to the fact that puberty and growth spurts make boys faster, stronger and larger, while puberty and growth spurts in girls are not always beneficial for girls in track and field events. The practical significance of the results relates to athletes developmental opportunities. Irrespective of whether young track and field athletes are relatively older or younger they should be met with patience and dedication from coaches. Superficial short-term categorization of young athletes potential do more harm than good.

Interacting Constraints and Relative Age Effect in Elite Cross-Country Skiers and Freeskiers.

Different characteristics of sports disciplines potentially lead to skewness in birth month distribution (relative age effect, RAE). These characteristics can be considered from a constraint-based approach with interacting environmental, task, and individual constraints as a theoretical framework with which to examine variations in RAE. The main aim of the present study was to examine the theoretical predictions of the constraint-based framework by investigating the birth month distribution in cross-country skiers and freeskiers at elite junior and senior levels. The sample was comprised of top ranked Norwegian U15-U19/20 cross-country skiers and junior-level freeskiers. Birth months of top ranked international senior-level skiers in cross-country and freeskiing were also collected. Results indicated an over-representation of skiers born in the first half versus the second half of the year at all junior ages in cross-country skiing. There was no significant difference in the distribution of birth months in freeskiing or in senior cross-country skiers or freeskiers. Based upon the interacting constraint framework, the skewness towards more early-born athletes in junior cross-country skiing could be due to strict age-grouped and results-oriented developmental programs beginning at an early age (environmental constraints) as well as high-demand for physical capabilities (task constraints) that favour more physically mature athletes (individual constraints). For freeskiing, the interacting environmental (less structured and more individualistic-oriented development), task (high technical/motor skill demands), and individual (no advantage of advanced physical maturation) constraints potentially operate in the opposite direction compared to cross-country skiing.

In Pursuit of a Comprehensive Understanding of Expertise Development: A Comparison between Paths to World-Class Performance in Complex Technical vs. Endurance Demanding Sports.

A comprehensive understanding of skill acquisition is important for different performance domains, and has practical implications for both sport sciences and public health. The study compared important constraints for expertise development in a physically demanding sport (cross-country skiing) versus a technically demanding sport (freeskiing). Eighteen world-class athletes reported the importance of different constraints for their developmental history subdivided into two age spans: (1) 7-15 years and (2) 16 years until present. The total amount of training did not differ between the groups, but from the age of 16, the cross-country skiers spend approximately 98% of their training specific to their main sport, compared to 75% for freeskiers. No differences were found between the distribution of organized versus non-organized training in main sport, but freeskiers reported a higher amount of unorganized training in other sports after the age of 16. No differences were found in perceived importance of facilities, enjoyment of performing their sport, or the need for early specialization of training. After the age of 16, the cross-country skiers reported a higher need for coach involvement compared to freeskiers. The two sports mainly share common paths to expertise but differ in the need for specific training and coach involvement.

Comparison of effects of training order of explosive strength and plyometrics training on different physical abilities in adolescent handball players.

While both plyometric and traditional resistance training methods are beneficial to athletic performance in a wide range of sports, their efficacy regarding training order has yet to be determined in a periodized training programme. Therefore, this study compared the effects of a 12-week training period where explosive strength training (six weeks) preceded plyometric training (six weeks), or vice versa. Forty-two competitive male (n = 12) and female (n = 30) adolescent handball players (age 14.9 ± 0.5 years, body mass 64.1 ± 9.1 kg, height 1.71 ± 0.09 m) conducted explosive strength training for six weeks followed by six weeks of plyometric training or vice versa. Variables included a 30 m sprint, a change of direction test, countermovement jump (CMJ) with and without arm swing, load-velocity back squat assessment, overhead throwing velocity with and without preliminary steps, and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). Both groups experienced similar improvements in the CMJ, change of direction and load-velocity squat assessments from pre- to posttest (p ≤ 0.013, η 2 = 0.194-0.378). Conversely, no improvements were observed in the Yo-Yo IR1, 30 m sprint or throwing velocity tests, regardless of group (p ≥ 0.081). No main effect of training order was observed for any of the tests employed (p ≥ 0.31). Training order does not appear to play a noticeable role in the physical development of young handball players. Therefore, practitioners could focus on implementing variations in exercise and loading to benefit athlete adherence and correspond to present needs.

The impact of physical growth and relative age effect on assessment in physical education.

Physical education (PE) is perhaps the school subject most likely to produce relative age effects (RAE). Like in sports, physical maturity gives students an advantage in PE, which might well be mistaken for superior ability. The aim of the present study is to investigate the extent to which physical growth, measured as height, and RAE reflect the assessment in Norwegian PE. Furthermore, we wanted to examine whether there is any gender differences in the assessment in PE as a function of physical growth and RAE. The participants (n = 2978) were pupils in the last three years of secondary school (13-16 years old). A custom-made questionnaire was designed to collect the necessary data. The correlations between height and mark in PE for boys in 8th, 9th, and 10th grades are respectively r = 0.14, r = 0.32, and r = 0.29. For girls, the correlations are r = 0.11, r = 0.33, and r = 0.21. All correlations are significant (p < .05). The number of pupils achieving top marks was 114 in the first half of the year, whereas it was 65 in the second half of the year. The present study showed that physical growth has an impact on the pupils' PE attainment. The physical growth is of course also mediated by the pupils' age. RAEs were found in PE attainments also in the Norwegian school system for both genders, despite all the intentions expressed in the PE curriculum.