Search Results

You are looking at 81 - 90 of 3,104 items for :

Clear All
Restricted access

Kate M. Sansum, Max E. Weston, Bert Bond, Emma J. Cockcroft, Amy O’Connor, Owen W. Tomlinson, Craig A. Williams and Alan R. Barker

Maximal oxygen uptake ( V ˙ O 2 max ), typically expressed in relation to a measure of body size, is the “gold-standard” measure of cardiorespiratory fitness (CRF) ( 10 ). A valid measurement of V ˙ O 2 max is important in children and adolescents because a high CRF in youth is associated with a

Restricted access

Jonathan S. Akins, Nicholas R. Heebner, Mita Lovalekar and Timothy C. Sell

Ankle ligament sprains are the most common injury in soccer. The high rate of these injuries demonstrates a need for novel data collection methodologies. Therefore, soccer shoes and shin guards were instrumented with inertial sensors to measure ankle joint kinematics in the field. The purpose of this study was to assess test-retest reliability and concurrent criterion validity of a kinematic assessment using the instrumented soccer equipment. Twelve soccer athletes performed athletic maneuvers in the laboratory and field during 2 sessions. In the laboratory, ankle joint kinematics were simultaneously measured with the instrumented equipment and a conventional motion analysis system. Reliability was assessed using ICC and validity was assessed using correlation coefficients and RMSE. While our design criteria of good test-retest reliability was not supported (ICC > .80), sagittal plane ICCs were mostly fair to good and similar to motion analysis results; and sagittal plane data were valid (r = .90−.98; RMSE < 5°). Frontal and transverse plane data were not valid (r < .562; RMSE > 3°). Our results indicate that the instrumented soccer equipment can be used to measure sagittal plane ankle joint kinematics. Biomechanical studies support the utility of sagittal plane measures for lower extremity injury prevention.

Restricted access

Pedro L. Valenzuela, Javier S. Morales, Carl Foster, Alejandro Lucia and Pedro de la Villa

 > .99) between the power output displayed by this cycle ergometer and a valid power meter, the SRM system (Schoberer Rad Messtechnik [SRM], Jülich, Germany), 8 during a laboratory test (mean difference between Cardgirus and SRM = 1 [2] W). Moreover, the physiological response to a laboratory test with

Restricted access

Do Young Pyun and Jeffrey D. James

A challenge with advertising communications is to better understand beliefs driving people’s attitude toward advertising. Successful use of sport communication requires a better understanding of the beliefs composing attitudes toward advertising through sport. A 4-phase study was conducted to develop a scale measuring 7 belief dimensions as indicants of attitude toward advertising through sport. Phase 1 (N = 125) provided an initial test of the proposed instrument. Phase 2 (N = 215) included an assessment of the revised scale based on internal-consistency tests and exploratory factor analysis. In Phase 3 (N = 424) the scale’s reliability and validity were verified using confirmatory factor analysis. In Phase 4 (N = 263) the internal consistency and factor structure of the scale were reexamined. The combined results provide support for the conceptualization and measurement of the belief dimensions for future investigation of the relationships between beliefs about and attitude toward advertising through sport.

Restricted access

Athanasios G. Papaioannou, Nikolaos Tsigilis, Eudoxia Kosmidou and Dimitrios Milosis

A new instrument of motivational climate in physical education is presented with the goal of measuring perceptions of teachers’ emphasis on mastery, performance–approach, performance–avoidance, and social approval goals. The measure was based on the principle of compatibility, according to which climate perceptions and achievement goals should be compatible between each other in terms of target, action domain, life context, and time. The measure was administered to 928 middle school students alongside scales of intrinsic motivation, amotivation, and satisfaction. The statistical analyses included structural equation modeling, investigation of factor correlations, correlation of this measure with intrinsic motivation, satisfaction, and amotivation in physical education and investigation of intraclass correlations. The findings provide evidence of construct validity for the new measure and suggest that mastery and social approval goals can facilitate intrinsic motivation of students.

Restricted access

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.

Restricted access

Jeremy M. Sheppard, Tim Gabbett, Kristie-Lee Taylor, Jason Dorman, Alexis J. Lebedew and Russell Borgeaud

Purpose:

The authors conducted a study to develop a repeated-effort test for international men’s volleyball. The test involved jumping and movement activity that was specific to volleyball, using durations and rest periods that replicated the demands of a match.

Methods:

A time–motion analysis was performed on a national team and development national team during international matches to determine the demands of competition and thereby form the basis of the rationale in designing the repeated-effort test. An evaluation of the test for reliability and validity in discriminating between elite and sub-elite players was performed.

Results:

The test jump height and movement-speed test parameters were highly reliable, with findings of high intraclass correlations (ICCs) and low typical errors of measurement (TE; ICC .93 to .95 and %TE 0.54 to 2.44). The national team’s ideal and actual jump height and ideal and actual speeds, mean ± SD, were 336.88 ± 8.31 cm, 329.91 ± 6.70 cm, 6.83 ± 0.34 s, and 7.14 ± 0.34 s, respectively. The development national team’s ideal and actual jump heights and ideal and actual speeds were 330.88 ± 9.09 cm, 323.80 ± 7.74 cm, 7.41 ± 0.56 s, and 7.66 ± 0.56 s, respectively. Probabilities of differences between groups for ideal jump, actual jump, ideal time, and actual time were 82%, 95%, 92%, and 96%, respectively, with a Cohen effect-size statistic supporting large magnitudes (0.69, 0.84, 1.34, and 1.13, respectively).

Conclusion:

The results of this study demonstrate that the developed test offers a reliable and valid method of assessing repeated-effort ability in volleyball players.

Restricted access

Patrick B. Wilson, Gregory S. Rhodes and Stacy J. Ingraham

Purpose:

Self-report (SR) has been the primary method used to assess fluid intake during endurance events, but unfortunately, little is known about the validity of SR. The purpose of this study was to compare SR fluid intake with direct measurement (DM) during a 70.3-mile triathlon.

Methods:

Fifty-three (42 men, 11 women) individuals competing in a 70.3-mile triathlon participated in the study. On the 13.1-mile-run section of the triathlon, 11 research stations provided fluid in bottles filled with 163 mL of water or carbohydrate-electrolyte beverage (CEB). Participants submitted bottles 25 m past aid stations to be reweighed postrace. Participants also answered questions regarding fluid intake postrace. Bland-Altman plots and 95% limits of agreement were used to assess precision of the measures, while least-squares regression assessed linear agreement.

Results:

SR intakes during the run ranged from 0–1793, 0–1837, and 0–2628 mL for water, CEB, and total fluid, with corresponding DM intakes of 0–1599, 0–1642, and 0–2250 mL. DM and SR showed strong linear agreement for water, CEB, and total fluid (R 2 = .71, .80, and .80). Mean differences between the measures on the Bland-Altman plots were small (13–41 mL), but relatively large differences (±500 mL) between the measures were apparent for some participants.

Conclusions:

SR is the predominant methodology used in field studies assessing hydration, despite little to no data confirming its validity. The results herein suggest that fluid-intake-assessment methodology should be chosen on a case-by-case basis and that caution should be used when interpreting data based on SR.

Restricted access

Iñigo Mujika, Greg McFadden, Mark Hubbard, Kylie Royal and Allan Hahn

Purpose:

To develop and validate an intermittent match-fitness test for water-polo players.

Methods:

Eight male junior players performed the Water Polo Intermittent Shuttle Test (WIST) twice to assess test reliability. To assess test sensitivity and validity, 104 male and female players from different competition standards and playing positions were tested. Eighteen players performed the WIST 5 times throughout a season to track fitness changes. Twelve players performed the WIST 48 hours before 4 consecutive National League games, and coaches awarded individual match-fitness scores based on game performances to assess the relationship between match fitness and test results. Heart rate (HR) and blood lactate (Lablood) were measured during and after each test, respectively.

Results:

Test–retest performance values were 216 ± 90 vs 229 ± 96 m (r = .98, P = .0001, coefficient of variation [CV] = 5.4%), peak HR 190 ± 8 vs 192 ± 10 bpm (r = .96, P = .0002, CV = 1.2%), and Lablood 7.0 ± 1.8 vs 6.4 ± 1.6 mmol/L (r = .84, P = .0092, CV = 8.8%). Significant differences were observed among different standards of play (range junior regional females 102 ± 10 m, senior international males 401 ± 30 m) and playing positions (field players 305 ± 154 m, center forwards 255 ± 118, goal keepers 203 ± 135 m). Test performance was lower in the early season (344 ± 118 m) than the remainder of the season (range 459 ± 138 to 550 ± 176 m). WIST performance and match-fitness scores correlated for all field players (r = .57, P = .054) but more highly for field players other than center forwards (r = .83, P = .0027).

Conclusions:

The WIST is a reliable, sensitive, and valid match-fitness test for water-polo players. It could become a useful tool to assess the effects of different interventions on match fitness.

Restricted access

Jonathan P. Norris, Jamie Highton and Craig Twist

possessing acceptable validity and reliability for locomotive demands, previous attempts to simulate the match demands of rugby league have resulted in similar heart rate (HR) responses but greater relative distance and high-speed running compared with match play. 5 The replication of collisions in the