Longitudinal study of aerobic performance and soccer-specific skills in male goalkeepers aged 11–18 years

he purpose of the current study was to evaluate the contribution of chronological age (CA), maturation, body size, and annual volume training to the longitudinal changes in aerobic performance and soccer-specific skills in youth soccer goalkeepers aged 11–18 years. A total of 16 goalkeepers were annually followed over a minimum of 3–5 years (4.4 measurements per goalkeeper). Anthropometric characteristics, training experience, and annual volume training were recorded. Performance was assessed by the 20-m shuttle run test, the dribbling speed test (time to complete the slalom course while dribbling the ball with the feet), and the wall pass test (number of passes made to a wall in 20 s). Multilevel modeling was used to predict developmental changes in aerobic performance, dribbling speed, and passing ability across ages. Based on multilevel models, the impact of age was a consistent source of variation in all performance indicators among goalkeepers aged 11–18 years [1 year predicts 192.5 m (37.02%), 0.35 s (2.26%), and 1 pass (6.11%) of improvement in aerobic performance, dribbling speed and passing ability, respectively]. Moreover, the predicted longitudinal scores for soccer-specific skills improved with the annual volume of training (1000 h predicts 3 s and 5 passes of improvement). Our results highlighted the importance of training in the development of aerobic performance and soccer-specific skills, and may provide a framework for trainers and coaches to develop and evaluate effective training programs for individual goalkeepers