1Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä, FINLAND; 2Department of Sport Sciences, University of Jyväskylä, FINLAND; and 3Department of Health Sciences, Gerontology Research Center, University of Jyväskylä, FINLAND.
Med Sci Sports Exerc. 2015 Jun;47(6):1188-96. doi: 10.1249/MSS.0000000000000527.
While the lack of muscular activity is a proposed trigger for metabolic alterations, this association has not been directly measured. We examined the associations between EMG-derived muscle inactivity and activity patterns and cardiometabolic biomarkers in healthy, physically active adults.
Data for this cross-sectional study were pooled from two studies (EMG24 and InPact), resulting in a sample of 150 individuals without known chronic diseases and with high-quality EMG data (female n = 85, male n = 65, age = 38.8 ± 10.6 yr, body mass index = 23.8 ± 3.1 kg·m⁻²). EMG was measured during one to three typical weekdays using EMG shorts, measuring quadriceps and hamstring muscle EMG. Muscle inactivity time and moderate- to vigorous-intensity muscle activity were defined as EMG amplitude below that of standing still and above that of walking 5 km·h⁻¹, respectively. Blood pressure index, waist circumference, fasting plasma glucose, HDL cholesterol, and triglycerides were measured, and long-term exercise behaviors were assessed by questionnaire.
In a group of physically active participants, muscles were inactive for 65.2% ± 12.9% of the measurement time in an average of 24.1 ± 9.8-s periods. Compared to those in the lowest muscle inactivity quartile (<55.5% of measurement time), those in the highest quartile (≥74.8% of measurement time) had 0.32 mmol·L⁻¹ lower HDL cholesterol (P < 0.05) and 0.30 mM higher triglycerides (P < 0.05) independent of muscle's moderate- to vigorous-intensity activity.
Clinically significant differences in HDL cholesterol and triglycerides were found, favoring participants having low muscle inactivity time, independent of moderate- to vigorous-intensity muscle activity. Even physically active individuals may benefit from light-intensity activities that reduce ubiquitous muscle inactivity time.
虽然肌肉活动不足被认为是代谢改变的一个诱因，但这种关联尚未被直接测量。我们研究了健康、活跃的成年人中肌电图（EMG）衍生的肌肉不活动与活动模式之间的关系，以及与心血管代谢生物标志物的关系。
本横断面研究的数据来自两项研究（EMG24 和 InPact），共纳入 150 名无已知慢性疾病且 EMG 数据质量高的个体（女性 n=85，男性 n=65，年龄 38.8±10.6 岁，体重指数 23.8±3.1kg·m⁻²）。使用 EMG 短裤在一到三个典型工作日内测量股四头肌和腘绳肌 EMG，测量期间肌肉不活动时间和中等到剧烈强度的肌肉活动分别定义为 EMG 幅度低于站立静止时的幅度和高于行走 5km·h⁻¹时的幅度。测量血压指数、腰围、空腹血糖、高密度脂蛋白胆固醇和甘油三酯，并通过问卷评估长期运动行为。
在一组活跃的参与者中，肌肉在测量时间的 65.2%±12.9%处于不活动状态，平均 24.1±9.8s 出现一次不活动。与肌肉不活动时间最低四分位数（<55.5%的测量时间）的参与者相比，最高四分位数（≥74.8%的测量时间）的参与者的高密度脂蛋白胆固醇低 0.32mmol·L⁻¹（P<0.05），甘油三酯高 0.30mM（P<0.05），独立于肌肉的中等到剧烈强度活动。
即使在身体活跃的个体中，降低普遍存在的肌肉不活动时间的低强度活动也可能对他们有益。与中等到剧烈强度肌肉活动相比，发现高密度脂蛋白胆固醇和甘油三酯存在有临床意义的差异，这有利于肌肉不活动时间较短的参与者。
