JOURNAL OF SPORTS SCIENCE & MEDICINE |
Research article |
FAMILIARISATION AND RELIABILITY OF SPRINT TEST INDICES DURING LABORATORY AND FIELD ASSESSMENT | |||||||||
James G. Hopker1, Damian A. Coleman2, Jonathan D. Wiles2 and Andrew Galbraith1 | |||||||||
1Centre for Sports Studies, University of Kent, Chatham Maritime, Chatham, Kent, UK, 2Department of Sport Science, Tourism and Leisure, Canterbury Christ Church University, Canterbury, Kent, UK . | |||||||||
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© Journal of Sports Science and Medicine (2009) 8, 528 - 532 | |||||||||
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ABSTRACT | ||||||||||||
The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg) and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0. 07 m, 62.7 ± 4.7 kg) performed a maximal 20-metre sprint running test on eight separate occasions. Four trials were conducted on a non-motorised treadmill in the laboratory; the other four were conducted outdoors on a hard-court training surface with time recorded by single-beam photocells. Trials were conducted in random order with no familiarisation prior to testing. There was a significant difference between times recorded during outdoor field trials (OFT) and indoor laboratory trials (ILT) using a non-motorised treadmill (3.47 ± 0.53 vs. 6.06 ±1.17s; p < 0.001). The coefficient of variation (CV) for time was 2.55-4.22% for OFT and 5.1-7.2% for ILT. During ILT peak force (420.9 ± 87.7N), mean force (147.2 ± 24.7N), peak power (1376.8 ± 451.9W) and mean power (514.8 ± 164.4W), and were measured. The CV for all ILT variables was highest during trial 1-2 comparison. The CV (95% confidence interval) for the trial 3-4 comparison yielded: 9.4% (7.7-12. 1%), 7.9% (6.4-10.2%), 10.1% (8.2-13.1%) and 6.2% (5.1-8.0%) for PF, MF, PP and MP and respectively. The results indicate that reliable data can be derived for single maximal sprint measures, using fixed distance protocols. However, significant differences in time/speed over 20-m exist between field and laboratory conditions. This is primarily due to the frictional resistance in the non- motorised treadmill. Measures of force and power during ILT require at least 3 familiarisations to reduce variability in test scores. Key words: Non-motorised treadmill, force, power, familiarisation, sprint running. |
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INTRODUCTION | ||||||||||||
Sprint performance is a key component of many sporting disciplines. This component of fitness is often assessed by the sport scientist to indicate athletic ability (Bird and Davidson, 1997; Logan et al., 2000), to monitor changes in training status (Linossier et al., 1993; MacDougall et al., 1998; McManus et al., 1997), and to ascertain the effect of ergogenic supplementation on performance (Bell et al., 2001; Collomp et al., 1991; Green et al., 2001). To ensure confidence in interpreting data from new equipment or protocols, the random variation of a subject's repeated measurement must be evaluated (Coleman et al., 2005) rather than accepting the manufacturer claims (Davison et al., 2000). This data allows the exercise scientist to select appropriate tests or tools (Atkinson and Nevill, 1998) that have adequate precision. In turn, this will allow the detection of small, nevertheless, worthwhile changes in performance. |
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METHODS | ||||||||||||
Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg) and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0.07 m, 62.7 ± 4.7 kg) participated in this study. These athletes were of mixed ability, ranging from collegiate to international standard in team sports. All experimental procedures were approved by the University Ethics Committee, and written informed consent was obtained from all participants. Protocol Outdoor field trials Indoor laboratory trials Statistical analyses |
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RESULTS | ||||||||||||
Preliminary data analysis indicated parametric assumptions were met for all parameters with the exception of the mean time to complete the sprint trials. These data were analysed using a Wilcoxon Signed Ranks test. The mean times recorded during the sprint trials were 3.47 ± 0.53 and 6.06 ± 1.17s for OFT and ILT sprints respectively (p < 0.01); with no significant change in time over the four trials for OFT (Table 1). However, during the ILT there was a significant reduction in time taken to complete the sprints from trial 1 to 2 (6.67 to 5.86s; p < 0.01), there were no further reductions in sprint time from trial 2-4 (p = 0.91). |
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DISCUSSION | ||||||||||||
The aims of this investigation were to compare the reliability of laboratory and field based sprinting and to assess any changes that occur with familiarisation during the two protocols. To enable the comparison of ILT and OFT a fixed distance protocol was used. However, due to the frictional resistance of the non-motorised treadmill belt it took participants considerably longer to complete the fixed distance in the laboratory. This should be considered when using the non-motorised treadmill to formulate protocols, since fixed distance work is often stipulated by guidelines on the assessment of athletes (Gore, 2000). If the non-motorised treadmill is used, distances would need to be adjusted to reflect the predominant energy systems that the investigator intended to stress. Similarly, if a non-motorised treadmill is used to assess sprint athletes (e.g. 100-m sprinters), it would be more appropriate to fix the duration of work rather than replicate the competitive distance. Even though fixed duration assessment may not be specific to field races, the measurement of performance in this manner compares favourably to fixed distance work (Hopkins et al., 2001). |
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AUTHORS BIOGRAPHY | |
James G. HOPKER Employment: Lecturer, Centre for Sports Studies at the University of Kent, UK. Degree: PhD. Research interests: Exercise physiology, the effect of training and training status on exercise efficiency. E-mail: j.g.hopker@kent.ac.uk | |
Damian A. COLEMAN Employment: Principal Lecturer, Department of Sport Science, Leisure and Tourism at Canterbury Christ Church University, Kent, UK. Degree: PhD. Research interests: Physiological assessment of athletes, energetics of competitive sport and the physiological evaluations of time-trial performance. E-mail: damian.coleman@canterbury.ac.uk | |
Jonathan D. WILES Employment: Senior Lecturer, Department of Sport Science, Leisure and Tourism at Canterbury Christ Church University, Kent, UK. Degree: PhD. Research interests: Exercise physiology, isometric training and blood pressure responses to training. E-mail: jim.wiles@canterbury.ac.uk | |
Andrew GALBRAITH Employment: Technician, Centre for Sports Studies at the University of Kent, UK. Degree: MSc. Research interests: Critical velocity and performance prediction in running. E-mail: a.galbraith@kent.ac.uk | |