Three years ago, Steve Thornton purchased the South End Mustangs, a professional ice hockey team competing in the D1 division in the United Kingdom. Unfortunately, Thornton has experienced challenging times during his ownership tenure. The team has achieved mediocre results on the ice and poor results off the ice. Thornton knows he needs help to turn the Mustangs franchise around. Thus, as a result, he turns to John Tapner, a sport business owner, operator, entrepreneur, and advisor. Tapner is best known as a professional sport consultant and TV personality, representing his company Sports Rescue, which is the same name as his hit television show. When an owner calls Tapner, it is because a professional sports team is in trouble and needs to be rescued.
Chris Chard and Kirsty K. Spence
Nenzi Wang and Yen-Hsiu Liu
An efficient global optimization procedure is presented by using Taguchi's design of experiments (TDE) as a means for undertaking biomechanical studies that rely on experimentations. The proposed TDE is a systematic method of fractional factorial designs for conducting experiments with many independent variables. The approach can provide a step-by-step means for predicting the results of a comparative full factorial design only with a small number of tests. In this study a three-level, four-variable heel-toe running model, and a two-level, seven-variable bicycle example were examined to show the capability and robustness of TDE. In the process of the analysis, the orthogonal array and signal-to-noise ratio analysis of TDE were used to set up the trial conditions and analyze the results. It is shown that in the heel-toe running analyses the TDE successfully predicted the optimum sets of variables with 89% fewer trials than the full factorial design. The reduction in number of trials in the bicycle example is 94%. As a result, the use of TDE analysis to replace a full factorial analysis can considerably reduce the number of trials and still provide a useful outcome in many multifactor biomechanical studies.
Samuel Ryan, Emidio Pacecca, Jye Tebble, Joel Hocking, Thomas Kempton and Aaron J. Coutts
Purpose: To examine the measurement reliability and sensitivity of common athlete monitoring tools in professional Australian Football players. Methods: Test–retest reliability (noise) and weekly variation (signal) data were collected from 42 professional Australian footballers from 1 club during a competition season. Perceptual wellness was measured via questionnaires completed before main training sessions (48, 72, and 96 h postmatch), with players providing a rating (1–5 Likert scale) regarding their muscle soreness, sleep quality, fatigue level, stress, and motivation. Eccentric hamstring force and countermovement jumps were assessed via proprietary systems once per week. Heart rate recovery was assessed via a standard submaximal run test on a grass-covered field with players wearing a heart rate monitor. The heart rate recovery was calculated by subtracting average heart rate during final 10 seconds of rest from average heart rate during final 30 seconds of exercise. Typical test error was reported as coefficient of variation percentage (CV%) and intraclass coefficients. Sensitivity was calculated by dividing weekly CV% by test CV% to produce a signal to noise ratio. Results: All measures displayed acceptable sensitivity. Signal to noise ratio ranged from 1.3 to 11.1. Intraclass coefficients ranged from .30 to .97 for all measures. Conclusions: The heart rate recovery test, countermovement jump test, eccentric hamstring force test, and perceptual wellness all possess acceptable measurement sensitivity. Signal to noise ratio analysis is a novel method of assessing measurement characteristics of monitoring tools. These data can be used by coaches and scientists to identify meaningful changes in common measures of fitness and fatigue in professional Australian football.
Rachel B. Parks, Hector F. Angus, Douglas S. King and Rick L. Sharp
, it can be partially hydrolyzed with hydrochloric acid and alcohol, producing modified amylomaize-7, which is 92% digestible and readily soluble in water ( Zhou & Kaplan, 1997 ). Johannsen and Sharp ( 2007 ) used 13 C isotope-ratio analysis to demonstrate that modified amylomaize-7 starch is