(Ap) and a drag coefficient (Cd), which is related to the shape of an object and the efficiency with which it moves through air. 6 The product of Ap and Cd is known as drag area (Ad). Reduction of this aerodynamic drag as a result of drafting can be expressed as a ratio (percentage) of the required
Levi Heimans, Wouter R. Dijkshoorn, Marco J.M. Hoozemans and Jos J. de Koning
Sjors Groot, Lars H.J. van de Westelaken, Dionne A. Noordhof, Koen Levels and Jos J. de Koning
According to the performance model of Joyner and Coyle, 1 performance power output or velocity is mainly determined by (1) maximal oxygen uptake ( V ˙ O 2 max), (2) V ˙ O 2 at the lactate threshold, (3) performance O 2 deficit (ie, anaerobic capacity), and (4) efficiency. The efficiency of an
Toshiki Kobayashi, Fan Gao, Nicholas LeCursi, K. Bo Foreman and Michael S. Orendurff
orthoses. The mechanical properties of AFOs, such as stiffness (moment per degree) and energy efficiency (ratio of released energy to stored energy), have been characterized using various mechanical testing devices, 1 – 3 and their effects on gait in individuals with neuromuscular diseases have been
Bradley D. Hatfield
nature. The purpose of this paper is to discuss the observed changes in the brain of such skilled performers in both the neurocognitive and affective domains. The model of psychomotor efficiency, first articulated by Hatfield and Hillman ( 2001 ) through a cognitive-affective motor neuroscience
Sean P. Wall, Carl G. Mattacola, C. Buz Swanik and Susan Levenstein
Overreaching can be beneficial, but there is a risk of overtraining.
To investigate the difference in sleep efficiency between overreached and nonover-reached swimmers.
Repeated-measures, between-subjects. Swimmers were determined to be overreaching if 2 or more of their consecutive weekly swim times increased by 5% or more from baseline.
9 competitive high school and university sprinter swimmers.
24-h wrist actigraph.
Main Outcome Measure:
Sleep efficiency as measured by the actigraph.
There was a significant difference in sleep efficiency on night 1 between the overreached and nonoverreached swimmers (P = .008), as well as in their times after averaging over all 5 trials and adjusting for baseline (P = .016). By the fourth swim trial, the overreached swimmers had significantly slower swim times than those of the nonoverreached swimmers (P = .001).
Sleep efficiency shows potential as an objective, noninvasive predictor and monitor of overreaching in swimmers.
Dennis van Erck, Eric J. Wenker, Koen Levels, Carl Foster, Jos J. de Koning and Dionne A. Noordhof
the maximal oxygen uptake [ V ˙ O 2 max] and V ˙ O 2 at the lactate threshold), performance O 2 deficit, and gross mechanical efficiency (GE). GE, defined as the percentage of metabolic power input, that is, converted into mechanical power output (PO), is considered the most valid definition of
Moniek Akkerman, Marco van Brussel, Bart C. Bongers, Erik H.J. Hulzebos, Paul J.M Helders and Tim Takken
The objective of this study was to investigate the characteristics of the submaximal Oxygen Uptake Efficiency Slope (OUES) in a healthy pediatric population. Bicycle ergometry exercise tests with gas-analyses were performed in 46 healthy children aged 7–17 years. Maximal OUES, submaximal OUES, V̇O2peak, VEpeak, and ventilatory threshold (VT) were determined. The submaximal OUES correlated highly with V̇O2peak, VEpeak, and VT. Strong correlations were found with basic anthropometric variables. The submaximal OUES could provide an objective, independent measure of cardiorespiratory function in children, reflecting efficiency of ventilation. We recommend expressing OUES values relative to Body Surface Area (BSA) or Fat Free Mass (FFM).
John L. Fizel and Michael D’itri
Data envelopment analysis, a linear programming technique, is used to estimate an objective measure of coaching efficiency. This method is applied using the performance records of 147 Division I college basketball teams from 1984 through 1991. The results indicate a wide dispersion in coaching efficiency, with the typical coach being very inefficient relative to the best coaches in the sample. It is also shown that additional experience apparently has no effect on coaching ability. Finally, coaching efficiency estimates provide a much different assessment of coaching performance than does a coach's winning percentage. These results imply that if coaching retention is based on winning percentage rather than coaching efficiency, excellent coaches will be ignored in hiring decisions and inappropriately dismissed in firing decisions if coaching retention is based on winning percentages rather than coaching efficiency.
April Karlinsky and Nicola J. Hodges
maximize training effectiveness and efficiency? Here we refer to the effectiveness of dyad practice as increased task performance in retention and/or transfer relative to individual conditions and to the efficiency of dyad practice as decreased trainer time and resources compared to practice alone. In the
Merel Walraven, Ruud H. Koning, Tammo H.A. Bijmolt and Bart Los
Over the last decades, sports sponsorship has become a popular and expensive marketing instrument. However, in business practice, projects are often not evaluated properly and academic research considering both costs and benefits of sponsorship is limited. In response to the concern that investments in sports sponsorship should be made more accountable, we propose data envelopment analysis (DEA) as a method for benchmarking sponsorship efficiency, and illustrate its usefulness by applying it on a sample of 72 major Dutch sports sponsorship projects. We find an average efficiency level of almost 0.3, which implies that the average project would have attained the same results with 30% of its fee if it had been performing as well as its benchmark. The results reveal that 12.5% of the investigated sponsorships are fully efficient. Moreover, we find a high degree of variety in efficiency scores; 37.5% of the projects with an efficiency below 0.1. In addition, we show how DEA scores may be used by sponsor managers to identify peers, which are those projects that attain roughly the same sponsorship outcomes, but at lowest budgets. After estimating the efficiency scores, a second step in the analyses involves investigating which sponsorship characteristics affect sponsorship efficiency. For this purpose, we use the DEA scores as a dependent variable in a Tobit regression model. The findings suggest that sponsorship clutter negatively affects sponsorship efficiency, whereas sponsorship duration has a positive effect.