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Tim J. Gabbett and Boris Georgieff

Purpose:

To develop a skill assessment for junior volleyball players and to evaluate the reliability, validity, and sensitivity of the test for detecting training-induced improvements in skill.

Methods:

Thirty junior volleyball players (mean ± SD age, 15.5 ± 1.0 years) participated in this study. Subjects performed tests of spiking, setting, serving, and passing skills on 2 separate occasions to determine test–retest reliability of accuracy. Two expert coaches evaluated the players’ technique and reevaluated it 1 month after the initial evaluation to determine the intratester reliability for technique measurements. A third expert coach determined the intertester reliability for technique measurements. The validity of the test to discriminate players of different playing abilities was evaluated by testing junior national, state, and novice volleyball players. Finally, each player participated in an 8-week skill-based training program.

Results:

Accuracy measurements and intratester and intertester ratings of players’ technique proved to be highly reproducible (intraclass correlation coefficient, r, .85 to .98, range of typical error of measurement 0.2% to 10.0%). A progressive improvement in skill was observed with increases in playing level, while training-induced improvements were present in all skill tasks.

Conclusions:

These results demonstrate that skill-based testing offers a reliable method of quantifying development and progress in junior volleyball players. In addition, the skill-testing battery was useful in successfully discriminating playing ability among junior volleyball players of varying levels, and it was sensitive to changes in skill with training. These fi ndings demonstrate that skill-based testing is useful for monitoring the development of junior volleyball players.

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Katie Weatherson, Lira Yun, Kelly Wunderlich, Eli Puterman and Guy Faulkner

occupational sitting time within office environments. 5 Interventions aimed at reducing sitting or increasing PA, depend on valid and reliable measures of these behaviours. 6 Retrospective self-report methods of assessing these behaviors rely on participants to recall past experience (within some defined

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James Wright, Thomas Walker, Scott Burnet and Simon A. Jobson

reliability and validity of the PowerTap P1 pedals have been investigated between 100 and 500 W at 70, 85, and 100 rpm. 7 These authors reported that the P1 pedals slightly underestimated the SRM Powermeter by 2 to 7 W but suggested that the pedals were reliable and valid, concluding that they were a cost

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Michael Wilkinson, Damon Leedale-Brown and Edward M. Winter

Purpose:

This study examined the validity of a squash-specific test designed to assess endurance capability and aerobic power.

Methods:

Eight squash players and eight runners performed, in a counterbalanced order, incremental treadmill (TT) and squash-specific (ST) tests to volitional exhaustion. Breath-by-breath oxygen uptake was determined by a portable analyzer and heart rate was assessed telemetrically. Time to exhaustion was recorded.

Results:

Independent t tests revealed longer time to exhaustion for squash players on the ST than runners (775 ± 103 vs. 607 ± 81 s; P = .003) but no difference between squash players and runners in maximal oxygen uptake ( Vo2max) or maximum heart rate (HRmax). Runners exercised longer on the TT (521 ± 135 vs. 343 ± 115 s; P = .01) and achieved higher Vo2max than squash players (58.6 ± 7.5 vs. 49.6 ± 7.3 mL·kg−1·min−1; P = .03), with no group difference in HRmax. Paired t tests showed squash players achieved higher Vo2max on the ST than the TT (52.2 ± 7.1 vs. 49.6 ± 7.3 mL·kg−1·min−1; P = .02). The Vo2max and HRmax of runners did not differ between tests, nor did the HRmax of squash players. ST and TT Vo2max correlated highly in squash players and runners (r = .94, P < .001; r = .88, P = .003).

Conclusions:

The ST discriminated endurance performance between squash players and runners and elicited higher Vo2max in squash players than a nonspecifc test. The results suggest that the ST is a valid assessment of Vo2max and endurance capability in squash players.

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Tiago V. Barreira, Robert M. Brouillette, Heather C. Foil, Jeffrey N. Keller and Catrine Tudor-Locke

The purpose of this study was to compare the steps/d derived from the ActiGraph GT3X+ using the manufacturer’s default filter (DF) and low-frequency-extension filter (LFX) with those from the NL-1000 pedometer in an older adult sample. Fifteen older adults (61–82 yr) wore a GT3X+ (24 hr/day) and an NL-1000 (waking hours) for 7 d. Day was the unit of analysis (n = 86 valid days) comparing (a) GT3X+ DF and NL-1000 steps/d and (b) GT3X+ LFX and NL-1000 steps/d. DF was highly correlated with NL-1000 (r = .80), but there was a significant mean difference (–769 steps/d). LFX and NL-1000 were highly correlated (r = .90), but there also was a significant mean difference (8,140 steps/d). Percent difference and absolute percent difference between DF and NL-1000 were –7.4% and 16.0%, respectively, and for LFX and NL-1000 both were 121.9%. Regardless of filter used, GT3X+ did not provide comparable pedometer estimates of steps/d in this older adult sample.

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Øystein Sylta, Espen Tønnessen and Stephen Seiler

Purpose:

The purpose of this study was to validate the accuracy of self-reported (SR) training duration and intensity distribution in elite endurance athletes.

Methods:

Twenty-four elite cross-country skiers (25 ± 4 y, 67.9 ± 9.88 kg, 75.9 ± 6.50 mL · min−1 · kg−1) SR all training sessions during an ~14-d altitude-training camp. Heart rate (HR) and some blood lactate measurements were collected during 466 training sessions. SR training was compared with recorded training duration from HR monitors, and SR intensity distribution was compared with expert analysis (EA) of all session data.

Results:

SR training was nearly perfectly correlated with recorded training duration (r = .99), but SR training was 1.7% lower than recorded training duration (P < .001). SR training duration was also nearly perfectly correlated (r = .95) with recorded training duration >55% HRmax, but SR training was 11.4% higher than recorded training duration >55% HRmax (P < .001) due to SR inclusion of time <55% HRmax. No significant differences were observed in intensity distribution in zones 1–2 between SR and EA comparisons, but small discrepancies were found in zones 3–4 (P < .001).

Conclusions:

This study provides evidence that elite endurance athletes report their training data accurately, although some small differences were observed due to lack of a SR “gold standard.” Daily SR training is a valid method of quantifying training duration and intensity distribution in elite endurance athletes. However, additional common reporting guidelines would further enhance accuracy.

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Matti Hyvärinen, Sarianna Sipilä, Janne Kulmala, Harto Hakonen, Tuija H. Tammelin, Urho M. Kujala, Vuokko Kovanen and Eija K. Laakkonen

in epidemiologic studies due to their relatively low cost and ease of implementation regardless of their limited reliability and validity due to the potential response bias and issues related to recalling the physical activity ( Kowalski, Rhodes, Naylor, Tuokko, & MacDonald, 2012 ; Shephard, 2003

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Carlos Augusto Kalva-Filho, Argyris Toubekis, Alessandro Moura Zagatto, Adelino Sanchez Ramos da Silva, João Paulo Loures, Eduardo Zapaterra Campos and Marcelo Papoti

minimum test and, consequently, its comparisons with other aerobic parameters (eg, critical velocity) ( 17 ). Although the lactate minimum test has been widely applied in free-swimming ( 5 , 14 , 17 , 26 ), at present, only one study has tested the validity of this procedure in tethered swimming

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Justin W.Y. Lee, Ming-Jing Cai, Patrick S.H. Yung and Kai-Ming Chan

user-friendly, the measurement largely depends on the skills and strength of the operator. 10 , 14 Especially for the hamstring strength endurance measurement, the operator will also fatigue during the trial. 5 For others on-field hamstring strength testing methods, the concurrent validity are yet to

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Kieran J. Marston, Belinda M. Brown, Stephanie R. Rainey-Smith, Sabine Bird, Linda K. Wijaya, Shaun Y. M. Teo, Ralph N. Martins and Jeremiah J. Peiffer

–40 continuous min; Jakicic, Winters, Lang, & Wing, 1999 ). It is, therefore, important to explore the acute response in BDNF, IGF-1, and VEGF using a high-intensity, yet, ecologically valid, resistance exercise regimen in older adults. The purpose of this investigation was to assess the acute response in BDNF