School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.
PLoS One. 2011;6(10):e25733. doi: 10.1371/journal.pone.0025733. Epub 2011 Oct 5.
Children and youth accumulate their daily moderate-to-vigorous physical activity (MVPA) in bouts (i.e., ≥ 5 consecutive minutes) and in a sporadic manner (i.e., <5 consecutive minutes). The study objective was to determine, within children and youth, whether MVPA accumulated in bouts is more strongly associated with cardiometabolic risk factors than an equivalent volume of MVPA accumulated sporadically.
Participants consisted of 2754 children and youth aged 6-19 years from the 2003-2006 National Health and Nutrition Examination Survey, a representative cross-sectional study. Bouts and sporadic MVPA were measured objectively over 7 days using Actigraph accelerometers. Thresholds of 5 and 10 consecutive minutes were used to differentiate between bouts and sporadic MVPA. A high cardiometabolic risk factor score (CRS) was created based on measures of waist circumference, non-high-density lipoprotein cholesterol, C-reactive protein, and systolic blood pressure. Associations were examined using logistic regression and controlled for covariates (sex, age, ethnicity, socioeconomic status, dietary fat and sodium, smoking, and accelerometry wear time).
The odds of a high CRS decreased in a dose-response for both the sporadic and bout MVPA measures. Relative to quartile 1, the odds ratio (95% confidence interval) for a high CRS in quartile 4 was 0.25 (0.10-0.60) for sporadic MVPA, 0.17 (0.09-0.34) for ≥ 5 minute bouts of MVPA, and 0.19 (0.11-0.34) for ≥ 10 minute bouts of MVPA. The sporadic and bout MVPA measures had a similar ability to distinguish between participants with high and normal CRS. Relative to 0 minutes of MVPA, an equivalent number of minutes of sporadic MVPA and bouts of MVPA had an almost identical odds ratio for a high CRS. The findings were consistent for 5 and 10 minute bout thresholds.
The relations between sporadic MVPA and bouts of MVPA with cardiometabolic risk factors were remarkably similar in children and youth.
儿童和青少年通过连续（即≥5 分钟）和不连续（即<5 分钟）的方式积累日常中中等至剧烈强度的身体活动（MVPA）。本研究的目的是在儿童和青少年中确定，与不连续的 MVPA 相比，连续的 MVPA 是否与心血管代谢风险因素的相关性更强。
参与者是来自 2003-2006 年全国健康和营养检查调查的 2754 名 6-19 岁的儿童和青少年，这是一项具有代表性的横断面研究。7 天内通过 Actigraph 加速度计客观地测量连续和不连续的 MVPA。使用 5 和 10 分钟的连续时间来区分连续和不连续的 MVPA。根据腰围、非高密度脂蛋白胆固醇、C 反应蛋白和收缩压的测量值创建高心血管代谢风险因素评分（CRS）。使用逻辑回归检查关联，并控制协变量（性别、年龄、种族、社会经济地位、饮食脂肪和钠、吸烟和加速度计佩戴时间）。
高 CRS 的几率呈剂量反应，无论是在不连续的 MVPA 还是连续的 MVPA 测量中。与四分位 1 相比，四分位 4 中高 CRS 的比值比（95%置信区间）分别为 0.25（0.10-0.60）、0.17（0.09-0.34）、0.19（0.11-0.34）。不连续的 MVPA 和连续的 MVPA 测量具有相似的能力来区分高和正常 CRS 的参与者。与 0 分钟的 MVPA 相比，不连续的 MVPA 和连续的 MVPA 的等效分钟数对于高 CRS 的比值比几乎相同。对于 5 分钟和 10 分钟的连续时间阈值，发现结果一致。
在儿童和青少年中，不连续的 MVPA 和连续的 MVPA 与心血管代谢风险因素之间的关系非常相似。
