Purpose: To understand how training periodization influences sprint performance and key step characteristics over an extended training period in an elite sprint training group. Methods: Four sprinters were studied during 5 mo of training. Step velocities, step lengths, and step frequencies were measured from video of the maximum velocity phase of training sprints. Bootstrapped mean values were calculated for each athlete for each session, and 139 within-athlete, between-sessions comparisons were made with a repeated-measures analysis of variance. Results: As training progressed, a link in the changes in velocity and step frequency was maintained. There were 71 between-sessions comparisons with a change in step velocity yielding at least a large effect size (>1.2), of which 73% had a correspondingly large change in step frequency in the same direction. Within-athlete mean session step length remained relatively constant throughout. Reductions in step velocity and frequency occurred during training phases of high-volume lifting and running, with subsequent increases in step velocity and frequency happening during phases of low-volume lifting and high-intensity sprint work. Conclusions: The importance of step frequency over step length to the changes in performance within a training year was clearly evident for the sprinters studied. Understanding the magnitudes and timings of these changes in relation to the training program is important for coaches and athletes. The underpinning neuromuscular mechanisms require further investigation but are likely explained by an increase in force-producing capability followed by an increase in the ability to produce that force rapidly.
Ian N. Bezodis, David G. Kerwin, Stephen-Mark Cooper and Aki I.T. Salo
Non-Eleri Thomas, Stephen-Mark Cooper, Simon P. Williams, Julien S. Baker and Bruce Davies
The purpose of this study was to examine relationships between aerobic fitness (AF), fatness, and coronary-heart-disease (CHD) risk factors in 12- to 13-year-olds. The data were obtained from 208 schoolchildren (100 boys; 108 girls) ages 12.9 ± 0.3 years. Measurements included AF, indices of obesity, blood pressure, blood lipids and lipoproteins, fibrinogen, homocysteine, and C-reactive protein. An inverse relationship was found between AF and fatness (p < .05). Fatness was related to a greater number of CHD risk factors than fitness was (p < .05). Further analysis revealed fatness to be an independent predictor of triglyceride and blood-pressure levels (p < .05). Our findings indicate that, for young people, fatness rather than fitness is independently related to CHD risk factors.
Lowri C. Edwards, Anna S. Bryant, Kevin Morgan, Stephen-Mark Cooper, Anwen M. Jones and Richard J. Keegan
Introduction: Despite increases in research and implementation, physical literacy continues to be largely misinterpreted by practitioners. The purpose of this study was to devise, implement, and evaluate a professional development program that works in a primary school environment to enhance their knowledge and operationalization of physical literacy. Methods: Following a 3-month needs assessment phase, data were collected from structured observations, reflections, and semistructured interviews with the teachers, before, during, and after an introductory workshop and 6-month physical literacy intervention. Thematic analysis was used to evaluate perceptions of program effectiveness. Results: The needs assessment phase identified notable differences between teachers’ classroom and physical education practice. Results of the physical literacy workshop and intervention detailed an increase in teachers’ knowledge of, and operationalization of, physical literacy. Discussion/Conclusions: Applying established principles of effective professional development in a contextually sensitive manner was viewed as effective in enhancing primary school teachers’ knowledge and practice regarding physical literacy.