title: Effect of Low-intensity Exercise on Physical and Cognitive Health in Older Adults: a Systematic Review.
abstract: BACKGROUND
  It is well known that physical exercise is important to promote physical and cognitive health in older population. However, inconsistent research findings were shown regarding exercise intensity, particularly on whether low-intensity exercise (1.5 metabolic equivalent tasks (METs) to 3.0 METs) can improve physical and cognitive health of older adults. This systematic review aimed to fill this research gap. The objective of this study is to conduct a systematic review of the effectiveness of low-intensity exercise interventions on physical and cognitive health of older adults.
  
  
  METHODS
  Published research was identified in various databases including CINAHL, MEDLINE, PEDro, PubMed, Science Direct, SPORTDiscus, and Web of Science. Research studies published from January 01, 1994 to February 01, 2015 were selected for examination. Studies were included if they were published in an academic peer-reviewed journal, published in English, conducted as randomized controlled trial (RCT) or quasi-experimental studies with appropriate comparison groups, targeted participants aged 65 or above, and prescribed with low-intensity exercise in at least one study arm. Two reviewers independently extracted the data (study, design, participants, intervention, and results) and assessed the quality of the selected studies. Fifteen studies met the inclusion criteria. Quality index ranged from 15 to 18 mean = 18.3 with a full score of 28, indicating a moderate quality. Most of the outcomes reported in these studied were lower limb muscle strength (n= 9), balancing (n= 7), flexibility (n= 4), and depressive symptoms (n= 3).
  
  
  RESULTS
  Out of the 15 selected studies, 11 reported improvement in flexibility, balancing, lower limb muscle strength, or depressive symptoms by low-intensity exercises.
  
  
  CONCLUSIONS
  The current literature suggests the effectiveness of low-intensity exercise on improved physical and cognitive health for older adults. It may be a desired intensity level in promoting health among older adults with better compliance, lower risk of injuries, and long-term sustainability.
authors.affiliation: Department of Health and Physical Education, Hong Kong Institute of Education, Tai Po, Hong Kong, China.
authors.forename: Andy C Y
authors.initials: AC
authors.lastname: Tse
authors.affiliation: Institute of Human Performance, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Thomson W L
authors.initials: TW
authors.lastname: Wong
authors.affiliation: School of Nursing, Hong Kong Polytechnic University, Hunghum, Hong Kong, China.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Lee
keywords: Cognitive health; Low-intensity exercise; Older adults; Physical health