Browsing Masters Dissertations by Authors
Factors affecting small-sided game demands among high-level junior rugby league playersTwist, Craig; Lamb, Kevin L.; Nicholas, Ceri; Foster, Christine (University of Chester, 2012)Small-sided games (SSGs) are commonly incorporated into the conditioning programmes of rugby league (RL) players. However, although several studies have examined the physiological, perceptual, movement and skill demands of SSGs, the majority of research in this area has focused on these responses in soccer players. Therefore, the purpose of this programme of research was to examine the effects of altering selected variables (player number, playing area size, the role of the player and the role of the coach) on the physiological and technical demands imposed on junior, high-level RL players during SSGs. In addition, SSG responses were investigated in different junior age groups to determine if playing age has an effect on SSG demands. Finally, given the role of SSGs as a conditioning tool, the consistency of the exercise intensities generated was assessed over repeated trials. Chapter 3 investigated the influence of player number and playing area size on the heart rate (HR) responses elicited by junior male RL players during SSGs. Twenty-two players from a professional club (mean age: 14.5 ± 1.5 yr; stature: 172.5 ± 11.4 cm; body mass: 67.8 ± 15.1 kg; 2OVpeak: 53.3 ± 5.6 ml·kg-1·min-1; HRmax: 198 ± 7.8 b·min-1) participated in two repeated trials of six four-minute conditioned SSGs over a two-week period. The SSGs varied by playing area size; 15x25 m, 20x30 m, and 25x35 m, and player number; 4v4 and 6v6. Analysis revealed non-significant (P>0.05) effects of trials and playing area size on HRs, but a significant effect of player number in the U16 age group only (P<0.001), with HRs being higher in the 4v4 (90.6% HRmax) than the 6v6 SSGs (86.2% HRmax). The HR responses were found to be repeatable in all SSG conditions (within ± 1.9% HRmax) apart from the small 6v6 condition in the older players. Chapter 4 investigated the HR responses and incidence of specific game actions during attacking and defending play in SSGs, with and without coach encouragement. Seventeen boys from a professional club (mean age: 13.4 ± 1.1 yr; stature: 168 ± 11.8 cm; body mass: 61.5 ± 14.9 kg; 2OVpeak: 55.0 ± 5.6 ml·kg-1·min-1; HRmax: 202 ± 6.5 b·min-1) participated in two repeated trials of four, four-minute conditioned SSGs over a two-week period. It was observed that attacking play elicited a greater amount of time above 90% HRmax than defending (62.0 ± 31.5 versus 48.4 ± 31.3% of total time). Compared to the older junior players (U15), the younger junior players (U13) elicited a greater average SSG intensity (90.5 ± 1.7% versus 87.9 ± 0.6% HRmax) and spent a greater amount of time above 90% HRmax (68.6 ± 22.5% versus 43.3 ± 34.6% of total time). Moreover, compared to the U15 players, the U13 players completed a greater volume of passes (20.8 ± 2.9 versus 15.5 ± 2.6), successful passes (21.3 ± 0.0 versus 17.4 ± 3.1), pass plays (6.6 ± 1.4 versus 3.0 ± 0.5) and tries (2.5 ± 1.1 versus 0.6 ± 0.3), but a lower volume of attacking runs (25.9 ± 1.3 versus 32.3 ± 0.2), dummy runs (10.6 ± 1.8 versus 18.9 ± 1.8), touches (30.0 ± 35.0 versus 35.8 ± 6.3), successful touches (30.5 ± 0.5 versus 42.1 ± 1.1) and completed sets (1.6 ± 0.0 versus 3.5 ± 0.6). The addition of coach encouragement had no effect on the HR responses or volume of game actions conducted. The SSGs demonstrated large trial-to-trial variability in the game actions and average and peak HR intensities (bias of 3.7 ± and ± 4% HRmax) and percentage of time in HR Zones (bias of ± 25% percentage of time), indicative of poor reliability. The findings from this research demonstrate that SSGs specific to RL can generate HR responses suitable for aerobic conditioning that, whilst unaffected by the size of the area used, are sensitive to the player number, player role and age. Moreover, coach encouragement may not affect SSG demands when players are habituated to SSG conditioning. Furthermore, manipulating SSG rules can adversely affect the reproducibility of HR responses.