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  • Author: Edward M. Winter x
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Edward M. Winter

In his “Editor’s Notes,” Rowland (15) raised an issue that is fundamentally important but frequently appears to be misunderstood. The issue is scaling, that is, the means of partitioning out differences in size. Because physiological variables are often dependent on size, an adjustment has to be made to “normalize” for body dimensions and assess more precisely a particular characteristic. These adjustments have four main applications: (a) to an individual who is compared against standards for the purposes of assessment; (b) in comparisons between groups; (c) in longitudinal studies, especially with children, in which for instance the effects of training have to be disentangled from the effects of growth and development; and (d) in studies that explore the relationship between physiological variables and performance. The purpose of this review is to assess the most appropriate means of scaling and demonstrate how well-intentioned, but nevertheless incorrect, scaling techniques have probably produced misleading results and retarded progress in our understanding of the physiology of exercise.

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

Purpose:

We examined the reproducibility of performance and physiological responses on a squash-specific incremental test.

Methods:

Eight trained squash players habituated to procedures with two prior visits performed an incremental squash test to volitional exhaustion on two occasions 7 days apart. Breath-by-breath oxygen uptake ( Vo2) and heart rate were determined continuously using a portable telemetric system. Blood lactate concentration at the end of 4-min stages was assessed to determine lactate threshold. Once threshold was determined, test speed was increased every minute until volitional exhaustion for assessment of maximal oxygen uptake (Vo2max), maximum heart rate (HRmax), and performance time. Economy was taken as the 60-s mean of Vo2 in the final minute of the fourth stage (below lactate threshold for all participants). Typical error of measurement (TEM) with associated 90% confidence intervals, limits of agreement, paired sample t tests, and least products regression were used to assess the reproducibility of scores.

Results:

Performance time (TEM 27 s, 4%, 90% CI 19 to 49 s) Vo2max (TEM 2.4 mL·kg−1·min−1, 4.7%, 90% CI 1.7 to 4.3 mL·kg−1·min−1), maximum heart rate (TEM 2 beats·min−1, 1.3%, 90% CI 2 to 4 beats·min−1), and economy (TEM 1.6 mL·kg−1·min−1, 4.1%, 90% CI 1.1 to 2.8 mL·kg−1·min−1) were reproducible.

Conclusions:

The results suggest that endurance performance and physiological responses to a squash-specific fitness test are reproducible.

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Alan D. Ruddock, Craig Boyd, Edward M. Winter and Mayur Ranchordas

Case studies are vehicles to bridge the gap between science and practice because they provide opportunities to blend observations and interventions that have taken place in real-world environments with scientific rigor. The purpose of this invited commentary is to present considerations for those providing applied sport science support to athletes with the intention of broadcasting this information to the scientific community. The authors present a 4-phased approach (1: athlete overview; 2: needs analysis; 3: intervention planning; and 4: results, evaluation, and conclusion) for scientific support to assist practitioners in the development and implementation of scientific support. These considerations are presented in the form of “performance questions” designed to guide and critically evaluate the scientific support process and aid the transfer of this knowledge through case studies.

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

Purpose:

We examined the validity and reproducibility of a squash-specifc test designed to assess change-of-direction speed.

Methods:

10 male squash and 10 male association-football and rugby-union players completed the Illinois agility run (IAR) and a squash change-of-direction-speed test (SCODS) on separate days. Tests were repeated after 24 h to assess reproducibility. The best time from three attempts was recorded in each trial.

Results:

Performance times on the IAR (TE 0.27 s, 1.8%, 90% CI 0.21 to 0.37 s; LOA -0.12 s ± 0.74; LPR slope 1, intercept -2.8) and SCODS (TE 0.18 s, 1.5%, 90% CI 0.14 to 0.24 s; LOA 0.05 s ± 0.49; LPR slope 0.95, intercept 0.5) were reproducible. There were no statistically significant differences in performance time between squash (14.75 ± 0.66 s) and nonsquash players (14.79 ± 0.41 s) on the IAR. Squash players (10.90 ± 0.44 s) outperformed nonsquash players (12.20 ± 0.34 s) on the SCODS (P < .01). Squash player rank significantly correlated with SCODS performance time (Spearman’s ρ = 0.77, P < .01), but not IAR performance time (Spearman’s ρ = 0.43, P = .21).

Conclusions:

The results suggest that the SCODS test is a better measure of sport-specific capability than an equivalent nonspecific field test and that it is a valid and reliable tool for talent identification and athlete tracking.