Department of Civil and Environmental Engineering, Michigan State University, Michigan, USA.
J Am Coll Nutr. 2020 Aug;39(6):580-581. doi: 10.1080/07315724.2019.1648068. Epub 2020 Jan 27.
The paper "Short-term Mediterranean Diet Improves Endurance Exercise Performance: A Randomized-Sequence Crossover Trial" (1), which was published in the Journal of the American College of Nutrition is based on the results of 11 individuals who each ran twice on a treadmill. The authors report that there was 6% decrease in the time required to run 5k after eating a Mediterranean diet for 4 days before the second run. The interpretation of the data is complicated by the small sample size and the fact that the results are highly skewed. The authors state that means and standard deviation of the two sets of data are "(27.09 ± 3.55 vs. 28.59 ± 3.21; = 0.030)", thereby implying that the test is a comparison of the means. However, the p refers to the result for a paired t-test. The authors discuss the several limitations of this study, but these limitations focus on the diets. They do not discuss how the fact that the testing is not blind may affect the results. It is stated that "recreationally active" 20-60 tear olds were recruited for this study "from the general population in metropolitan St. Louis, MO". However, the runners tested had a tight range of run times (27.09 ± 3.55), age (28 ± 3), and BMI (24.6 ± 3.2). This hardly seems like a random sample of this group.
这篇论文“短期地中海饮食可提高耐力运动表现：一项随机序列交叉试验”（1）发表在《美国营养学院杂志》上，该研究基于 11 名个体在跑步机上进行两次跑步的结果。作者报告说，在第二次跑步前的 4 天内食用地中海饮食后，跑完 5 公里所需的时间减少了 6%。由于样本量小且结果高度偏斜，数据的解释变得复杂。作者指出，两组数据的均值和标准差分别为“（27.09 ± 3.55 与 28.59 ± 3.21；= 0.030）”，这意味着该测试是对均值的比较。然而，p 指的是配对 t 检验的结果。作者讨论了这项研究的几个局限性，但这些局限性主要集中在饮食方面。他们没有讨论测试不是盲法可能如何影响结果。文中称，“休闲活跃”的 20-60 岁成年人从密苏里州圣路易斯大都市区的普通人群中招募来参加这项研究。然而，接受测试的跑步者的跑步时间（27.09 ± 3.55）、年龄（28 ± 3）和 BMI（24.6 ± 3.2）范围非常狭窄。这似乎不太像是该群体的随机样本。
