Dual-energy X-ray absorptiometry (DXA) is a popular technique used to quantify physique in athletic populations. Due to biological variation, DXA precision error (PE) may be higher than desired. Adherence to standardized presentation for testing has shown improvement in consecutive-day PE. However, the impact of short-term diet and physical activity standardization prior to testing has not been explored. This warrants investigation, given the process may reduce variance in total body water and muscle solute, both of which can have high daily flux amongst athletes. Twenty (n = 10 males, n = 10 females) recreationally active individuals (age: 30.7 ± 7.5 years; stature: 176.4 ± 9.1 cm; mass: 74.6 ± 14.3 kg) underwent three DXA scans; two consecutive scans on 1 day, and a third either the day before or after. In addition to adhering to standardized presentation for testing, subjects recorded all food/fluid intake plus activity undertaken in the 24 hr prior to the first DXA scan and replicated this the following 24 hr. International Society of Clinical Densitometry recommended techniques were used to calculate same- and consecutive-day PE. There was no significant difference in PE of whole-body fat mass (479 g vs. 626 g) and lean mass (634 g vs. 734 g) between same- and consecutive-day assessments. Same- and consecutive-day PE of whole-body fat mass and lean mass were less than the smallest effect size of interest. Inclusion of 24-hr standardization of diet and physical activity has the potential to reduce biological error further, but this needs to be verified with follow-up investigation.

双能 X 射线吸收测定法 (DXA) 是一种流行的技术，用于量化运动人群的体质。由于生物变异，DXA 精度误差 (PE) 可能高于预期。坚持标准化的测试演示已显示连续日 PE 有所改善。然而，尚未探索测试前短期饮食和身体活动标准化的影响。这值得进行调查，因为该过程可能会减少全身水分和肌肉溶质的差异，这两者在运动员中可能具有很高的每日通量。二十 ( n  = 10 男性, n = 10 名女性）从事娱乐活动的个体（年龄：30.7 ± 7.5 岁；身高：176.4 ± 9.1 厘米；体重：74.6 ± 14.3 千克）进行了三次 DXA 扫描；一天连续两次扫描，前一天或后一天进行第三次扫描。除了遵守标准化的测试演示之外，受试者还记录了所有食物/液体摄入量以及在第一次 DXA 扫描之前 24 小时内进行的活动，并在接下来的 24 小时内重复了这一点。国际临床密度测定学会推荐的技术用于计算同一天和连续一天的 PE。在同一天和连续一天的评估之间，全身脂肪量（479 克对 626 克）和瘦体重（634 克对 734 克）的 PE 没有显着差异。全身脂肪量和瘦体重的同日和连续日 PE 小于感兴趣的最小效应值。