Health and Use of Time (HUT) Group, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia.
Sports Med. 2013 Feb;43(2):135-49. doi: 10.1007/s40279-012-0008-7.
The ActivityStat hypothesis suggests that when physical activity is increased or decreased in one domain, there will be a compensatory change in another domain, in order to maintain an overall stable level of physical activity or energy expenditure over time. The ActivityStat debate is gaining momentum in the literature and most of the research to date is based on observational studies.
The objective of this paper is to conceptually clarify the ActivityStat hypothesis and to examine the experimental research aiming to demonstrate or refute compensation using a systematic review process.
A systematic review was conducted using electronic database searches with the aim of detecting studies experimentally investigating the ActivityStat hypothesis or compensation in physical activity or energy expenditure. Included studies were critically appraised using a specifically designed tool to address the conceptual considerations of the ActivityStat hypothesis.
Searches identified 28 studies that met the inclusion criteria. Publications spanned 26 years and had multiple methodological approaches, including randomized and non-randomized controlled trials, crossover designs, cluster randomized controlled trials and pre-post trials. Populations of the included studies ranged from children, to adults and the elderly, across a range of weight statuses and used both aerobic, resistance and mixed-exercise interventions. The timeframe of interventions ranged from 1 day to 4 years and outcomes were measured using doubly labelled water, accelerometry, heart rate monitoring, resting metabolic rate, indirect calorimetry, pedometry, subjective recall questionnaire and the activity-related time index. Fifteen of 28 included studies provided evidence of compensation, while 13 did not. Subgroup analyses by population, type and duration of intervention, weight status and study quality also showed mixed findings.
There is a substantial body of experimental literature investigating compensation that has largely been overlooked in the ActivityStat debate. However, this evidence is currently inconclusive and lacks a cohesive approach to the question of an ActivityStat. Recommendations for the design of future experimental research investigating the ActivityStat hypothesis are presented.
活动状态假说认为，当身体活动在一个领域增加或减少时，另一个领域会发生代偿性变化，以保持身体活动或能量消耗的整体稳定水平。活动状态假说的争论在文献中越来越激烈，迄今为止，大多数研究都是基于观察性研究。
本文旨在从概念上澄清活动状态假说，并通过系统综述过程检验旨在证明或反驳补偿的实验研究。
使用电子数据库搜索进行系统综述，旨在检测实验研究，以调查身体活动或能量消耗中的活动状态假说或补偿。纳入的研究使用专门设计的工具进行批判性评估，以解决活动状态假说的概念考虑。
搜索确定了 28 项符合纳入标准的研究。出版物跨越了 26 年，采用了多种方法，包括随机和非随机对照试验、交叉设计、集群随机对照试验和前后试验。纳入研究的人群从儿童到成年人和老年人，涵盖了一系列体重状况，并使用了有氧、阻力和混合运动干预措施。干预的时间范围从 1 天到 4 年不等，使用双标记水、加速度计、心率监测、静息代谢率、间接测热法、计步器、主观回忆问卷和与活动相关的时间指数来测量结果。28 项纳入研究中有 15 项提供了补偿的证据，而 13 项没有。按人群、干预类型和持续时间、体重状况和研究质量进行的亚组分析也显示出混合结果。
有大量实验文献研究补偿，但在活动状态假说的争论中被忽视了。然而，目前的证据尚无定论，也缺乏对活动状态假说的一致看法。提出了对调查活动状态假说的未来实验研究设计的建议。
