Background: Intermittent high-intensity endurance is a relevant component of fitness in competitive basketball players. In particular, it may be relevant for the successful
development of young basketball players. The present 4-month longitudinal study examined physical growth and development of intermittent endurance run performance in young Brazilian basketball players
aged 11–15 years applying multilevel regression modeling to partition the influence of growth, body size, training experience, training and game exposure.
Methods: Anthropometry, maturity offset, years of training experience and Yo-Yo Intermittent Recovery level 1 test (Yo-Yo IR1) of players from the under-12, under-13, under 14 and
under-15 teams were measured at pre- and end- 4 month competitive season (n = 44 considered for analysis). Training and game exposure were recorded across the 4 month period of observation.
Three-level longitudinal models were adopted considering with each measurement (level 1) within each player (level 2) nested by age group team (Level 3).
Results: A substantial increase in Yo-Yo IR1 was observed across the for 4-month period (37.9%, CL 18.5 to 0.57), considering the significant random effects for both intercept and
changes across the 4-month period at level 2 (between players) and level 3 (between age-group teams). The changes of Yo-Yo IR1 performance, accounting for the age group differences, were
significantly influenced by somatic maturity status and body mass (p<0.01). Game exposure had a significant influence in Yo-Yo IR1 changes (p=0.01) in contrast to training exposure (p=0.18) and years
of experience in formal basketball training (p=0.18).
Conclusions: The changes of intermittent endurance run performance in response to a 4 month competitive period, during pubertal years, in young Brazilian basketball players appear to
be mostly influenced by inter-individual variation in biological maturity status and and game exposure. The results highlight the importance of considering multilevel modeling to interpret the complex
interactions of growth, training and game exposure on performance development in adolescent basketball players.
Acknowledgements: The first author was supported by a grant from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [PNPD/CAPES/2013]. The patience and cooperation of the young athletes,
coaches and parents is acknowledged by the authors.