Effects of exercise intensity and frequency on improving cognitive performance in middle-aged and older adults with mild cognitive impairment: A pilot randomized controlled trial on the minimum physical activity recommendation from WHO

Abstract

Background: The World Health Organization physical activity guidelines recommend adults and older adults to accumulate at least 150–300 min of moderate or 75–150 min of vigorous aerobic-type physical activity weekly for health benefits including improvements of cognitive performance. However, the optimal exercise intensity and frequency for maximizing the cognitive benefits remain unclear.Purpose: We conducted a parallel, assessor-blinded, pilot randomized controlled trial to evaluate the effectiveness of different intensities and frequencies of the WHO-recommended minimal volume of aerobic-type physical activity on improving cognitive performance in middle-aged and older adults with mild cognitive impairment (MCI).Methods: Participants were randomly allocated to the stretching exercise control group (CON), once-a-week and thrice-a-week moderate-intensity walking groups (M1 and M3), and once-a-week and thrice-a-week vigorous-intensity walking groups (V1 and V3). Intervention duration was 12 weeks. The primary outcome was global cognitive performance assessed by the Hong Kong version of Montreal Cognitive Assessment. Secondary outcomes were self-report and objective cognitive performances, mental health, sleep quality, and cardiorespiratory fitness.Results: Thirty-seven participants completed the study (CON: n = 7, M1: n = 7, M3: n = 7, V1: n = 8, V3: n = 8). Participants in all four walking exercise groups demonstrated significant improvements in global cognitive performance assessed by the Hong Kong version of the Montreal Cognitive Assessment after the intervention when compared to CON (p < 0.001). The walking exercise interventions also significantly mitigated the anxiety severity (p < 0.005) and improved the cardiorespiratory fitness (p < 0.05) of the participants in the walking exercise groups.Conclusion: 150-min moderate- or 75-min vigorous-intensity walking exercise performed once- or thrice-weekly showed similar effects on improving cognitive performance in middle-aged and older adults with MCI. The 12-week walking exercise interventions also reduced anxiety severity and improved cardiorespiratory fitness of the participants.Clinical Trial Registration:clinicaltrials.gov, identifier NCT04515563

Comparative efficacy of various exercise interventions on sleep in patients with cognitive impairment: a systematic review and meta-analysis

“…Among the excluded records, 14 articles were rejected for reasons such as no sleep outcome ( n = 4), intervention noncompliance ( n = 5), participant noncompliance ( n = 1), language noncompliance ( n = 1), result non-match the data ( n = 1), non-randomized controlled trial ( n = 1), and protocol ( n = 1). Eventually, nine randomized controlled studies ( 25–33 ) were included in the SR-MA, with eight eligible for meta-analyses. The selection process, presented using the PRISMA flowchart, is depicted in Figure 1 .…”

“…This study presents a comprehensive analysis of nine RCTs conducted between 2011 and 2022. These trials were comprised of a two-arm RCT ( 29 ), a five-arm RCT ( 25 ), a cluster RCT ( 30 ), and six parallel-group RCTs. The majority of the trials (seven out of nine) were conducted in China, while one trial was conducted in Turkey ( 26 ) and another in the United States ( 33 ).…”

“…Alzheimer’s disease was diagnosed using either the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V) or the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer’s Disease and Related Disorders Association (NINCDS-ADRA). Of the nine studies included in this systematic review and meta-analysis, two reported on AD ( 28 , 33 ), six enrolled MCI ( 25–27 , 29 , 30 , 32 , 33 ), and one reported on both AD and MCI ( 31 ). Four studies reported sleep problems before exercise interventions ( 26–28 , 33 ).…”

“…The present meta-analysis examined the effects of various types of physical exercise on health outcomes. Specifically, four studies employing aerobic exercise ( 25 , 28 , 29 , 33 ), three studies on mind–body exercise ( 27 , 30 , 31 ), and two studies utilizing multi-component exercise in conjunction with multiple exercise types ( 26 , 32 ) were included in the review, without resistance exercise intervention. The exercise time of each intervention ranged from 20–150 min, with frequency ranging from once a week to once a day.…”

Physical activity improves the visual–spatial working memory of individuals with mild cognitive impairment or Alzheimer’s disease: a systematic review and network meta-analysis

“…The study indicates that moderate exercise intensity significantly enhances VSWM in patients with MCI and AD. A recent study found that moderate to high-intensity exercise has similar beneficial effects on cognitive function in patients with cognitive impairment ( 86 ). A small number of high-intensity intervention experiments were used in our study, and all of the subjects were over 70 years old.…”