Hopkins W G, Hawley J A, Burke L M
Department of Physiology and School of Physical Education, University of Otago, Dunedin, New Zealand.
Med Sci Sports Exerc. 1999 Mar;31(3):472-85. doi: 10.1097/00005768-199903000-00018.
The purpose of this study was to assess research aimed at measuring performance enhancements that affect success of individual elite athletes in competitive events.
Simulations show that the smallest worthwhile enhancement of performance for an athlete in an international event is 0.7-0.4 of the typical within-athlete random variation in performance between events. Using change in performance in events as the outcome measure in a crossover study, researchers could delimit such enhancements with a sample of 16-65 athletes, or with 65-260 in a fully controlled study. Sample size for a study using a valid laboratory or field test is proportional to the square of the within-athlete variation in performance in the test relative to the event; estimates of these variations are therefore crucial and should be determined by repeated-measures analysis of data from reliability studies for the test and event. Enhancements in test and event may differ when factors that affect performance differ between test and event; overall effects of these factors can be determined with a validity study that combines reliability data for test and event. A test should be used only if it is valid, more reliable than the event, allows estimation of performance enhancement in the event, and if the subjects replicate their usual training and dietary practices for the study; otherwise the event itself provides the only dependable estimate of performance enhancement. Publication of enhancement as a percent change with confidence limits along with an analysis for individual differences will make the study more applicable to athletes. Outcomes can be generalized only to athletes with abilities and practices represented in the study.
estimates of enhancement of performance in laboratory or field tests in most previous studies may not apply to elite athletes in competitive events.
本研究旨在评估旨在衡量影响个体精英运动员在竞技赛事中取得成功的成绩提升的研究。
模拟结果表明，在国际赛事中，运动员成绩的最小有价值提升为赛事间运动员成绩典型随机变化的0.7 - 0.4。在交叉研究中，以赛事成绩变化作为结果指标，研究人员可以通过16 - 65名运动员的样本确定此类提升，在完全受控研究中则需要65 - 260名运动员。使用有效实验室或现场测试的研究样本量与测试中运动员成绩变化相对于赛事成绩变化的平方成正比；因此，这些变化的估计至关重要，应由对测试和赛事可靠性研究数据进行重复测量分析来确定。当测试和赛事中影响成绩的因素不同时，测试和赛事中的成绩提升可能会有所不同；这些因素的总体影响可以通过结合测试和赛事可靠性数据的效度研究来确定。只有当测试有效、比赛事更可靠、能够估计赛事中的成绩提升，并且受试者在研究中重复其通常的训练和饮食习惯时，才应使用该测试；否则，赛事本身是成绩提升的唯一可靠估计。以带有置信区间的百分比变化形式公布成绩提升并进行个体差异分析，将使该研究更适用于运动员。结果仅可推广到研究中所代表的具有相应能力和训练习惯的运动员。
大多数先前研究中实验室或现场测试的成绩提升估计可能不适用于竞技赛事中的精英运动员。
