Silva A M, Santos D A, Matias C N, Júdice P B, Magalhães J P, Ekelund U, Sardinha L B
Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Cruz-Quebrada, Portugal.
1] MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK [2] Department of Sport Medicine, Norwegian School of Sport Sciences, Oslo, Norway.
Eur J Clin Nutr. 2015 Jan;69(1):20-7. doi: 10.1038/ejcn.2014.51. Epub 2014 Apr 2.
BACKGROUND/OBJECTIVES: A combined heart rate (HR) and motion sensor (Actiheart) has been proposed as an accurate method for assessing total energy expenditure (TEE) and physical activity energy expenditure (PAEE). However, the extent to which factors such as caffeine may affect the accuracy by which the estimated HR-related PAEE contribution will affect TEE and PAEE estimates is unknown. Therefore, we examined the validity of Actiheart in estimating TEE and PAEE in free-living adults under a caffeine trial compared with doubly labeled water (DLW) as reference criterion.
SUBJECTS/METHODS: Using a double-blind crossover trial (Clinicaltrials.gov ID: #NCT01477294) with two conditions (4-day each with a 3-day-washout period), randomly ordered as caffeine (5 mg/kg per day) and placebo (malt-dextrine) intake, TEE was measured by DLW in 17 physically active men (20-38 years) who were non-caffeine users. In each condition, resting energy expenditure (REE) was assessed by indirect calorimetry and PAEE was calculated as (TEE-(REE+0.1 TEE)). Simultaneously, PAEE and TEE were estimated by Actiheart using an individual calibration (ACC+HRstep).
Under caffeine, ACC+HRstep explained 76 and 64% of TEE and PAEE from DLW, respectively; corresponding results for the placebo condition were 82 and 66%. No mean bias was found between ACC+HRstep and DLW for TEE (caffeine:-468 kJ per day; placebo:-407 kJ per day), although PAEE was slightly underestimated (caffeine:-856 kJ per day; placebo:-1147 kJ per day). Similar limits of agreement were observed in both conditions ranging from -2066 to 3002 and from -3488 to 1776 kJ per day for TEE and PAEE, respectively.
Regardless of caffeine intake, the combined HR and motion sensor is valid for estimating free-living energy expenditure in a group of healthy men but is less accurate for an individual assessment.
背景/目的：心率（HR）与运动传感器（Actiheart）相结合被认为是评估总能量消耗（TEE）和身体活动能量消耗（PAEE）的一种准确方法。然而，诸如咖啡因等因素对估计的与心率相关的PAEE贡献影响TEE和PAEE估计准确性的程度尚不清楚。因此，我们以双标记水（DLW）作为参考标准，研究了Actiheart在咖啡因试验中对自由生活成年人估计TEE和PAEE的有效性。
受试者/方法：采用双盲交叉试验（Clinicaltrials.gov标识符：#NCT01477294），设置两种情况（每种情况为期4天，有3天的洗脱期），随机安排为摄入咖啡因（每天5mg/kg）和安慰剂（麦芽糊精），通过DLW测量17名不摄入咖啡因、身体活跃的男性（20 - 38岁）的TEE。在每种情况下，通过间接测热法评估静息能量消耗（REE），PAEE计算为（TEE - （REE + 0.1TEE））。同时，Actiheart使用个体校准（ACC + HRstep）估计PAEE和TEE。
在咖啡因摄入情况下，ACC + HRstep分别解释了来自DLW的TEE和PAEE的76%和64%；安慰剂情况下的相应结果分别为82%和66%。对于TEE，ACC + HRstep与DLW之间未发现平均偏差（咖啡因：每天 - 468kJ；安慰剂：每天 - 407kJ），尽管PAEE被轻微低估（咖啡因：每天 - 856kJ；安慰剂：每天 - 1147kJ）。在两种情况下观察到的一致性界限相似，TEE和PAEE每天分别为 - 2066至3002kJ和 - 3488至1776kJ。
无论咖啡因摄入量如何，心率与运动传感器相结合对于估计一组健康男性的自由生活能量消耗是有效的，但对于个体评估准确性较低。
