Reliability and validity of the Yo-Yo intermittent recovery test level 1 in young soccer players

Abstract

The present study investigated the test-retest reliability from the Yo-Yo IR1 (distance and heart rate responses), and the ability of the Yo-Yo IR1 to differentiate between elite and non-elite youth soccer players. A total of 228 youth soccer players (11–17 years) participated: 78 non-elite players to examine the test-retest reliability within 1 week, added with 150 elite players to investigate the construct validity. The main finding was that the distance covered was adequately reproducible in the youngest age groups (U13 and U15) and highly reproducible in the oldest age group (U17). Also, the physiological responses were highly reproducible in all age groups. Moreover, the Yo-Yo IR1 test had a high-discriminative ability to distinguish between elite and non-elite young soccer players. Furthermore, age-related standards for the Yo-Yo IR1 established for elite and non-elite groups in this study may be used for comparison of other young soccer players.     

Characteristics of high-level youth soccer players: variation by playing position

The present study aimed to investigate positional differences in 744 high-level soccer players, aged 8 to 18 years. Players were assigned to six age groups (U9–U19) and divided into four playing positions (goalkeeper (GK), defender (DEF), midfielder (MF) and attacker (ATT)). MANOVA and effect sizes were used to examine anthropometrical and functional characteristics between all positions in all age groups. The main findings of the study were that GKs and DEFs were the tallest and heaviest compared with MFs and ATTs in all age groups. Further, between U9–U15, no significant differences in functional characteristics were found, except for dribbling skill, which MFs performed the best. In the U17–U19 age groups, ATTs seemed to be the most explosive (with GKs), the fastest and the more agile field players. These results suggest that inherent physical capacities (i.e., speed, power, agility) might select players in or reject players from an attacking position, which is still possible from U15–U17. Apparently, players with excellent dribbling skills at younger age are more likely to be selected to play as a MF, although, one might conclude that the typical physical characteristics for different positions at senior level are not yet fully developed among young soccer players between 8 and 14 years.     

A longitudinal study of multidimensional performance characteristics related to physical capacities in youth handball

Abstract

Longitudinal research provides valuable information about change and progress towards elite performance. Unfortunately, there is a lack of longitudinal research in handball. In this study, 94 youth handball players (oldest group: n = 41; age 15–17 and youngest group: n = 53; age 13–15) were followed over a three-year period. Repeated Measures ANCOVA was conducted to reveal longitudinal changes in anthropometry and physical performance between elite and non-elite players, controlling for maturation. Maturation effects were found for anthropometry (P < 0.01) and some physical performance measures in strength and speed (P < 0.05). The lack of significant interaction effects revealed that during the three years of the study the elite players did not improve their physical performance more rapidly than the non-elites. Furthermore, they had a similar anthropometric profile to the non-elites. Elite players performed better on the Yo-Yo Intermittent Recovery test (P < 0.01; on average 24.0 in the youngest group and 25.2% in the oldest group over the three years) and on the speed and coordination items (P < 0.05; shuttle run: 3.6 and 5.1%; cross hopping: 11.0 and 14.8%, handball-specific shuttle run: 7.6 and 7.7%; slalom dribble test: 10.7 and 8.9%; sprint 30 m: 4.9 and 3.9%). Additionally, Yo-Yo performance and coordination with and without a ball were the most discriminating factors between the playing levels. In conclusion, youth coaches and scouts within team handball should recognise the importance of good skills and an excellent endurance for talent identification purposes.     

Participatory planning for project sustainability of environmental education projects: a case study of the Secondary Teacher Training Environmental Education Project (St2eep) in Zimbabwe

Within the first year of the Secondary Teacher Training Environmental Education Project (St²eep) in Zimbabwe, project stakeholders, including lecturers, college administrators, local project coordinators, and donor representatives, expressed concern about the non‐sustainability of the project due to its over‐reliance on its international donor. In response to this challenge, a process of critical self‐reflection through self‐assessment workshops was started to give an opportunity for key project stakeholders to explore the challenge of project sustainability. Applying the principles of expansive learning theory to St²eep’s reflection processes, this paper shows how the contradictions that emerge from the interaction between different project stakeholders can be powerful sources for learning. This has resulted in new forms of activity to address the challenge of project sustainability in St²eep. The insights of this paper may be useful for other donor‐funded environmental education projects that are confronted with the challenge of project sustainability.