The effects of sprint and bounds training on 0-30 m running speed in elite adolescent rugby league players Cale Wallace B.Ed (Social Science) Master of Philosophy November 2008 Statement of Originality This work contains no material which has been accepted for the award of any other degree or diploma in any university or other tertiary institution and, to the best of my knowledge and belief, contains no material previously published or written by another person, except where due reference has been made in the text. I give consent to this copy of my thesis, when deposited in the University Library, being made available for loan and photocopying subject to the provisions of the Copyright Act 1968. Acknowledgement of Authorship I hereby certify that the work embodied in this Thesis is the result of original research, the greater part of which was completed subsequent to admission to candidature for the degree. Signature:………………………………………….. Date:……………………………. Acknowledgements I would like to thank Dr Robin Callister for her expertise in the areas of sports science and statistical analysis. Your efforts in refining my thesis were outstanding and truly appreciated. Professor Ronald S. Laura, you are a great friend and mentor and I thank you for your motivation and encouragement throughout the project. Mum, you were my inspiration for this degree. You helped me persevere when I wanted to give up. Everything seems so easy now. Rebekah, it’s finished. Lets move on to the next chapter. Love Cale. Table of Contents    Abstract  Introduction.................................................................................................................i  Methods......................................................................................................................i  Results.........................................................................................................................i  Discussion..................................................................................................................ii  Conclusion.................................................................................................................ii  Chapter 1 1.0 Introduction..........................................................................................................1  1.1 Aims.....................................................................................................................2  1.2 Hypotheses...........................................................................................................2  Chapter 2 Literature review  2.1 Overview..............................................................................................................3  2.2 Adolescence.........................................................................................................3  2.3 Age and maturation..............................................................................................5  2.4 The Bio-cultural matrix – developmental framework.........................................5  2.4.1 Biological characteristics..............................................................................6  2.4.1.1 Changes in body size and timing of maturational change.........................7  2.4.1.2 Changes in physiological and cognitive characteristics.............................8  2.4.1.3 Development and exercise training............................................................9  2.4.1.4 Maturation and training..............................................................................9  2.4.1.5 Distinguishing the effects of growth and training....................................10  2.4.1.6 Growths spurts and training.....................................................................10  2.4.1.7 Proposed ‘optimal periods’ for development of speed capacities...........11  2.4.1.7.1 Movement coordination.....................................................................11  2.4.1.7.2 Muscular strength...............................................................................13  2.4.1.7.3 Flexibility and mobility......................................................................13  2.4.1.7.4 Movement speed................................................................................14  2.4.1.7.5 Aerobic capacity................................................................................14  2.4.1.7.6 Anaerobic capacity.............................................................................15  2.4.1.7.7 Reaction time.....................................................................................15  2.4.2 Social characteristics...................................................................................15  2.4.2.1 Influence of parents..................................................................................16  2.4.3 Psychological characteristics......................................................................16  2.5 Summary............................................................................................................17  2.6 Factors contributing to sprint speed...................................................................19  2.6.1 Stride frequency..........................................................................................19 2.6.2 Stride length................................................................................................19  2.6.3 Flexibility and mobility...............................................................................20  2.6.4 Coordination...............................................................................................20  2.6.5 Efficiency of movement..............................................................................20  2.6.6 Energy provision for sprinting....................................................................21  2.6.6.1 Children are not metabolic specialists.....................................................21  2.6.7 Reaction time..............................................................................................22  2.7 100-m sprint and team-sports sprint models......................................................23  2.7.1 100-metre sprint model...............................................................................23  2.7.2 Team-sports sprint model...........................................................................25  2.8 Contributions to speed - initial movement and acceleration..............................28  2.8.1 Technique....................................................................................................28  2.8.1.1 Acceleration technique..........................................................................29  2.8.1.2 How force is applied during acceleration.............................................30  2.8.1.3 Muscle mechanics during acceleration.................................................30  2.8.1.4 Pick up acceleration (PMA)..................................................................31  2.8.1.5 Training for technique...........................................................................31  2.8.1.6 Relevance to adolescents......................................................................32  2.8.2 Mobility.......................................................................................................33  2.8.2.1 Training for mobility.............................................................................33  2.8.2.2 Relevance to adolescents......................................................................33  2.8.3 Strength.......................................................................................................34  2.8.3.1 Maximum strength................................................................................34  2.8.3.2 Power performance...............................................................................35  2.8.3.3 Training for strength and power...........................................................36  2.8.3.4 Plyometric training................................................................................37  2.8.3.5 Bounding as a safe training tool............................................................38  2.8.3.6 Training for power................................................................................38  2.8.3.7 Relevance to adolescents......................................................................39  2.8.4 Coordination – synthesised modes of training............................................40  2.8.4.1 Training for acceleration.......................................................................41  2.8.4.2 Training for maximal velocity..............................................................41  2.8.4.3 Relevance to adolescents......................................................................43  2.8.5 Turnover......................................................................................................43  2.8.5.1 Training for turnover.............................................................................44  2.8.5.2 Relevance to adolescents......................................................................44  2.8.6 Muscle endurance.......................................................................................45  2.8.6.1 Training for muscle endurance.............................................................45  2.8.6.2 Relevance to adolescents......................................................................46  2.8.7 Energy systems...........................................................................................46  2.8.7.1 Relevance to adolescents......................................................................46  2.9 Summary....................................................................................................46  2.10 Responses to exercise training in adolescents.................................................47  2.10.1 Distinguishing training effects from those of growth and maturation......48  2.10.2 Training to improve anaerobic performance in children..........................49  2.10.3 Importance of testing specificity...............................................................49  2.10.4 Speed training in adolescence ..................................................................50  2.10.4.1 The impact of development on speed training....................................51  2.10.4.2 Evaluation of the effects of speed training.........................................51  2.10.5 Plyometric training in adolescents............................................................57 2.10.5.1 Plyometric activities............................................................................57  2.10.5.2 The impact of development on plyometric performance....................58  2.10.5.3 Evaluation of the effects of plyometric training.................................58  2.10.6 Strength training in adolescents................................................................62  2.10.6.1 The impact of development on strength training................................63  2.10.6.2 Evaluation of the effects of strength training .....................................63  2.10.6.3 Muscle endurance...............................................................................64  2.10.7 Aerobic training in children......................................................................69  2.10.7.1 Effects of aerobic training in children................................................69  2.10.7.2 The impact of development on aerobic training.................................71  2.10.7.3 Selection bias of subjects....................................................................72  2.10.7.4 Intensity and specificity of training....................................................73  2.10.7.5 Specific effects of training..................................................................74  2.10.7.6 Evaluation of the effects of aerobic exercise......................................75  2.10.7.7 Limitations of VO maximum test protocols......................................76  2 2.10.8 Energy systems in children.......................................................................81  2.10.9 Adolescent’s capacity to adapt to a training program...............................81  2.10.10 Importance of speed to adolescent sports performance..........................82  2.11 Summary..........................................................................................................83  Chapter 3  Methods  3.1 Study design.......................................................................................................84  3.2 Subjects..............................................................................................................84  3.2.1 Health screening questionnaire...................................................................85  3.3 Exercise Testing.................................................................................................85  3.3.1 Warm-up and cool down.............................................................................86  3.3.2 Speed and bounds testing conditions..........................................................86  3.3.3 Timing of sprints.........................................................................................87  3.3.4 Measurement of bounding distance............................................................87  3.4 Training..............................................................................................................87  3.4.1 Fitness training............................................................................................90  3.4.2 Speed training.............................................................................................90  3.4.3 Bounds training...........................................................................................90  3.5 Statistical analysis..............................................................................................91  Chapter 4  Results  4.1 Participants.........................................................................................................93  4.2 Attrition..............................................................................................................93  4.3 Attendance at training........................................................................................94  4.4 Comparison of groups prior to training.............................................................94  4.4.1 Analysis of responses to training of completers.........................................94 Chapter 5  Discussion  5.1 Introduction to discussion..................................................................................97  5.2 Participants and attrition....................................................................................97  5.3 Influence of pre-training sprint speed on responses to training.........................98  5.4 Influence of pre-training bounds performance on responses to training...........98  5.5 Training effects on 10 m and 30 m speed..........................................................98  5.6 Training effects on bounds performance.........................................................100  5.7 Training program-specific effects on sprint speed and bounds performance..100  5.7.1 Effects of fitness training on sprint speed.................................................100  5.7.2 Effects of fitness training on bounds performance...................................101  5.7.3 Effects of sprint training on sprint speed..................................................102  5.7.4 Effects of sprint training on bounds performance.....................................102  5.7.5 Effects of sprint and bounds training on sprint speed...............................103  5.7.6 Effects of sprint and bounds training on bounds performance.................103  5.8 Limitations of the study and recommendations...............................................104  5.8.1 Group stratification prior to group assignment.........................................104  5.9 Future directions..............................................................................................105  5.10 Conclusion.....................................................................................................106  Appendix A  Ethics Documents..................................................................................................108  Appendix B  Data........................................................................................................................119  Bibliography Tables  Table 2.1 Definitions of terms relating to adolescent development..............................4 Table 2.2 Interactions of Growth, Maturation, and Development.................................6 Table 2.3 Definition of terms relating to speed and power training............................18 Table 2.4 Proposed relative importance of maximum leg strength and speed strength qualities for sprint performance...................................................................................35 Table 2.5 Plyometric training for the lower body........................................................39 Table 2.6 Factors affecting the intensity of lower body plyometric drills...................39 Table 2.7 Lower body plyometric drills......................................................................40 Table 2.8 Training variables to improve acceleration and maximal velocity..............40 Table 2.9 Factors affecting the intensity of short speed drills......................................41 Table 2.10 Speed training studies in boys 10-17 years old..........................................54 Table 2.11 Summary of speed trained adolescent athletes compared to other adolescent training groups............................................................................................55 Table 2.12 Summary of plyometric training studies in adolescent boys 10-17 years old.................................................................................................................................60 Table 2.13 Summary of strength training studies with adolescents 10-17 years.........66 Table 2.14 Summary of training studies on aerobic activity in males 10-17years old.................................................................................................................................77 Table 2.15 Cross-sectional studies reporting aerobic capacity in 10-17 year old males.............................................................................................................................80 Table 3.1 Warm up drills performed at the beginning of each training session..........86 Table 3.2 Ballistic stretching performed after the warm up drills...............................86 Table 3.3 Sprint training program (total volume 3490 metres)...................................88 Table 3.4 Bounds training program (total volume 450 foot contacts).........................89 Table 3.5 Rugby league fitness program (total volume 45-60 minutes).....................89 Table 4.1 Numbers of participants per group across study..........................................93 Table 4.2 Comparison of performance results of groups prior to training..................94 Table 4.4 Responses to training from completers analysis..........................................95 Table 4.5 P-values for responses to training from completers analysis.......................95 Table 4.6 Effect-sizes of responses to training, descriptive categorisation of size of effects of responses to training....................................................................................96  Figure  Figure 2.1 Framework for sprint performance ………………………………………44 Abstract Introduction Forty-six elite adolescent male rugby league players (12-17 years) participated in a nine-week study to determine the effects of three exercise training programs on 0-30 metres sprint running time and bounds performance (10 bounds). Subjects were randomly assigned to a rugby league fitness group (F) n=12, a sprint group (S) n= 14 and a sprint-bounds group (SB) n= 20. Forty-two subjects completed the study. Methods Separate sessions for fitness, speed, and bounds were conducted once a week for nine weeks. To determine the effect of training a two-way analysis of variance was performed, followed by post-hoc paired t-tests to allow pairwise comparisons when significant interactions were found. Significance was set at p<0.05. Statistical analysis was performed using SPSS for Mac (version 13.1). Effect sizes were calculated to evaluate the meaningfulness of observed changes. Results Moderate improvements (p<0.05; 5%) were observed in both the F and SB groups over 10 m. Speed changes over 30 m differed more among the groups. The F group recorded moderate (p<0.01; 4%) improvements, small improvements (p<0.01; 3%) in the SB group and trivial difference (p<0.05) in the S group. The F and S groups improved by approximately 7% (p<0.01) in bounds performance over 10 bounds whereas the SB group improved by approximately 10% (p<0.01) in bounds performance over 10 bounds. Group S had faster sprint times (p<0.05) prior to training compared to groups F and SB. i Discussion All three programs led to improvements in sprint speed and bounds distance, but the extent of the improvements varied with the specificity of the training program and pre-training performance level. Groups F and SB had 4-5% improvements in sprint speed over 30 m whereas group S showed relatively trivial changes. In all groups, the improvements were greater over 10 m and least over 30 m. Bounds distance improved more than sprint speed, and the greatest improvement was achieved in the SB group compared to the F and S groups. Conclusion Rugby league training (game specific drills and extended efforts) coupled with the various components of physical activity can improve speed and power as effectively as specific speed and power training in adolescent boys. Training for acceleration can selectively improve 0-10 m speed more than 0-30 m speed. Sprint and bounds training have been shown to be safe and effective methods to increase speed and power in this group of adolescents. ii