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Levi Heimans, Wouter R. Dijkshoorn, Marco J.M. Hoozemans and Jos J. de Koning

(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

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Geoffrey T. Burns, Kenneth M. Kozloff and Ronald F. Zernicke

movement. Why? Beyond its role in our evolutionary history, it is not unreasonable to wonder—why should we still focus on efficient movement? It is easy to appreciate the role of efficiency in optimizing athletic performance, where competition puts a premium on maximizing effectiveness while minimizing

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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

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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

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Richard Ebreo, Louis Passfield and James Hopker

Gross efficiency (GE) is defined as the ratio of work generated to the metabolic energy cost and has been shown to be a key component of cycling performance. 1 , 2 The calculation of GE is conventionally determined from steady state measures where energy expenditure from purely aerobic processes

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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.

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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

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Arthur H. Bossi, Wouter P. Timmerman and James G. Hopker

Cycling efficiency describes the relationship between mechanical power output and metabolic power input, and it is a determinant of endurance performance. 1 Hence, gross efficiency (GE), the most valid index of cycling efficiency, 1 can be expressed by GE ( % ) = [ mechanical power output   ( J

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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

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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).