Assessment and manipulation of training practices in adolescent athletes

PhD Thesis

Dudley, C.. (2024). Assessment and manipulation of training practices in adolescent athletes [PhD Thesis]. Sports Performance, Recovery, Injury & New Technologies (SPRINT) Research Centre School of Behavioural and Health Sciences
AuthorsDudley, C.
TypePhD Thesis
Qualification nameDoctor of Philosophy

Adolescent athletic development is a complex process. There are a number of challenges adolescent athletes face that influence their training practices. As such, this thesis aimed to 1) investigate the methods of monitoring and the distribution of training practices of adolescent athletes and examine the relationship with changes in physical qualities; and 2) assess how manipulating task-constraints (i.e., pitch size and player numbers) can influence the physical, technical and subjective task-load demands of training. To investigate these aims, 81 individuals were recruited across four study in conjunction with the industry partner, St Joseph’s Nudgee College.
Study one systematically examined the research assessing internal and external methods of monitoring training load and changes in physical qualities, injury, or illness in adolescent athletes. The most reported load monitoring tools were session ratings of perceived exertion (n = 29) and training duration (n = 22). Results of the best-evidence synthesis identified moderate evidence of positive relationships between resistance training volume load and improvement in strength, and between throw count (i.e., number of pitches or bowls) and injury. However, evidence for other relationships between training load and change in physical qualities, injury, or illness were limited or inconsistent.
Study two quantified the training loads in adolescent rugby players, as well as the relationship between training loads and changes in physical qualities, and the changes in levels of stress and recovery throughout an 8-week pre-season period. Subjects completed (mean ± S.D) 5.60 ± 1.60 total training sessions per week, with 2.45 ± 0.34 resistance training sessions and 2.73 ± 0.54 field training sessions. Conditioning drills had the greatest running intensity (145.2 ± 47.8 m/min), whereas small-sided games (SSG) had the greatest acceleration density (0.46 ± 0.13 AU/min). Significant improvements (p < 0.05) in isometric mid-thigh pull (IMTP) peak force, Bench Press, and 2km run time were observed. Large degrees of multi-collinearity were present (all variance inflation factor > 10). Relationships between training load variables and changes in physical qualities were assessed using elastic net regression, with number of full body exercises having the greatest importance.
As identified in study two, the IMTP is a commonly implemented method of assessing strength. Study three investigated the validity and reliability of strapped and taped grip, figure eight straps, and bare hand grip during the IMTP. Compared to the straps and tape condition, using only bare hands to grasp the bar reduced peak force (p < 0.01) while the figure eight strap condition allowed for similar (p = 0.42; ES = 0.08 ± 1.14) outcomes. All conditions were found to have acceptable reliability (CV% = 5.36 - 5.67%) for peak force, but all rate of force development (RFD) and impulse outcome measures were not reliable irrespective of grip. These findings demonstrate that practitioners who wish to use the IMTP to assess peak force should use either straps and tape, or figure eight straps. It is advised that practitioners use figure eight straps, as was used in study two, due to their equivalence in reliability, but increased efficiency and practicality.
Study four assessed the variability of physical, technical, and subjective task-load demands in SSG, and the effect of manipulating of pitch size and player numbers in SSG on these demands in adolescent Rugby Union players. This study was conducted as SSG were the most commonly used conditioning tool evidenced in study two. In each condition subjects played 4 × 3-min periods of an SSG. Games were completed with either 4 × 4, 6 × 6 or 12 × 12 players on either a small (W: 25 m, L: 30 m), medium (W: 30 m, L: 40 m), or large (W: 35 m, L: 50 m) sized pitch. A substantial range of variability was observed in technical (CV = 25.00 to 52.38%), physical (CV = 4.12 to 51.18%) and subjective task-loads (CV = 7.65 to 17.14%) between identical games. Reducing player numbers increased physical demands such as m/min (ES range = 0.44 to 1.45; p = <0.01), technical exposures such as total involvements (ES range = 0.04 to 0.63; p range = <0.01 to 0.64) and effort, physical and temporal task-loads. Increasing pitch size caused greater movement demands such as m/min (ES range = 0.11 to 0.79; p = <0.01 to 0.62), but did not change the technical demands.

KeywordsAdolescent; Athlete; Training; Small-sided Games
PublisherAustralian Catholic University
Digital Object Identifier (DOI)
Research or scholarlyResearch
Page range1-242
Final version
File Access Level
Supplementary Files (Layperson Summary)
All rights reserved
File Access Level
Output statusPublished
Publication dates
Online07 Jul 2024
Publication process dates
Accepted27 Jun 2024
Deposited07 Jul 2024
Additional information

This work © 2024, Charles Dudley.

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