Effects of Exercise Training on Executive Functioning in Adults with Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Effects of aerobic exercise on executive function of healthy middle-aged and older adults: A systematic review and meta-analysis

BACKGROUND

The deterioration of executive function is a hallmark of cognitive aging. Reports indicate that signs of decline in executive function begin to emerge as early as middle age. Aerobic exercise improves executive function in healthy middle-aged and older adults, but the optimal exercise prescription variables are still unclear.

OBJECTIVE

To investigate the effects of aerobic exercise on executive function of healthy middle-aged and older adults and explore the dose-response relationship and moderators.

METHODS

We conducted comprehensive searches of PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, PsycINFO, and SPORTDiscus for English literature, and CNKI, WanFang, and VIP for Chinese literature, covering the period from inception until April 25, 2024. Randomized controlled trials examining the effect of aerobic exercise on executive function in healthy middle-aged and older adults aged 45 or older were included. The Cochrane Collaboration's RoB2 tool was used to assess the methodological quality of the included studies. And subgroup analyses and meta-regressions were conducted to elucidate the impact of aerobic exercise on executive function.

RESULTS

Forty-two eligible randomized controlled trials, involving a total of 2881 participants, met the inclusion criteria for the systematic review and meta-analysis. The pooled results showed that aerobic exercise had positive effects on improving cognitive flexibility (Hedge's g = 0.343, p < 0.001), working memory (Hedge's g = 0.392, p < 0.001), and inhibitory control (Hedge's g = 0.229, p < 0.001) in healthy middle-aged and older adults. However, it did not demonstrate an improvement in planning (Hedge's g = 0.094, p = 0.440). The dose-response relationships between different exercise parameters and subdomains of executive functions revealed that the largest effects on cognitive flexibility were observed after 13-24 weeks of progression-intensity mind-body exercise, 46-60 min per session, and 5-7 days per week. Regarding working memory, the largest effects were observed after 13-24 weeks of progression-intensity general aerobic exercise, 20-45 min per session, and 5-7 days per week. For inhibitory control, the greatest effects were noted after 13-24 weeks of low-intensity general aerobic exercise, 20-45 min per session, and 3-4 days per week.

CONCLUSION

Aerobic exercise can significantly improve cognitive flexibility, working memory, and inhibitory control in healthy middle-aged and older adults. The effect of aerobic exercise on different aspects of executive function is influenced by specific exercise parameters, suggesting that personalized aerobic exercise programs may be more effective for enhancing executive function of healthy middle-aged and older adults.

The efficacy of exercise interventions on depressive symptoms and cognitive function in adults with depression: An umbrella review

OBJECTIVE

This umbrella review aims to consolidate the evidence concerning the influence of exercise on depressive symptoms and cognitive performance in adults diagnosed with depression.

METHODS

An umbrella review of systematic reviews with meta-analyses investigating the effect of exercise on depression and cognition was performed. Databases (PubMed, Cochrane Library, Web of Science, Embase) were searched from inception until February 2024 for reviews of randomized controlled trials. Overlap within included reviews was assessed using the corrected covered area method (CCA). A random effects model was used to calculate overall pooled effect size with sub-analyses.

RESULTS

This study included 27 reviews, encompassing 190 experiments. In patients with depression, compared to the control group, exercise demonstrated a moderate effect size in reducing depressive symptoms (SMD = -0.67; SE = 0.04; p < 0.0001), with a Number Needed to Treat (NNT) of 2.78. When analyses were limited to data from studies with a low risk of bias, the effect on depressive symptoms was smaller (SMD = -0.38; SE = 0.07; p < 0.0001; NNT = 4.72). Exercise had a small effect on cognitive functions (SMD = 0.12; SE = 0.03; p < 0.0001), with an NNT for cognitive function treatment of 14.79.

CONCLUSIONS

All forms of exercise benefit patients with depression. However, for optimal intervention outcomes, it is essential to customize the intensity and type of exercise according to the specific characteristics of the patient's depressive symptoms and cognitive functions. It is recommended to implement a phased treatment approach for patients based on the intensity of exercise.

Intervention effect of exercise on working memory in patients with depression: a systematic review

Background

This article aims to systematically evaluate the intervention effect of exercise on working memory in patients with depression.

Methods

Six Chinese and English databases were searched for randomized controlled trials (RCTs) about exercise on working memory in patients with depression. PEDro scale was adopted to evaluate the methodological quality of the included articles, GRADEpro scale was employed to evaluate the level of evidence for outcomes, and the Metafor Package in R 4.4.1 was used to analyze the combined effect size, subgroup analyses and publication bias.

Results

A total of 15 studies were included. The meta-analysis indicated that exercise had a statistically significant effect on working memory in patients with depression, with an effect size of 0.16 (95% CI [0.03-0.28], p = 0.02). Exercise type (F(3,34) = 1.99, p = 0.13), intervention content (F(1,36) = 1.60, p = 0.22), and exercise duration (F(1,36) = 0.05, p = 0.83) did not moderate the effect, whereas exercise intensity showed a moderating effect (F(2,35) = 8.83, p < 0.01). There was evidence of publication bias in the study results (t = 2.52, p = 0.02).

Conclusion

Exercise can improve the working memory of patients with depression, and its moderating effect is the best when having low-intensity and moderate-intensity. Research plan was registered in international system evaluation platform PROSPERO (https://www.crd.york.ac.uk/PROSPERO/) (CRD42023475325).

PEAK Mood, Mind, and Marks: a pilot study of an intervention to support university students' mental and cognitive health through physical exercise

Introduction

Regular exercise has the potential to enhance university students' mental and cognitive health. The PEAK Mood, Mind and Marks program (i.e., PEAK) is a neuroscience-informed intervention developed using the Behaviour Change Wheel to support students to exercise three or more times per week to benefit their mental and cognitive health. This pilot study assessed the impact of PEAK on exercise, mental and cognitive health, and implementation outcomes.

Methods

PEAK was delivered to 115 undergraduate university students throughout a 12-week university semester. The primary outcome was weekly exercise frequency. Secondary outcomes were: time spent engaged in moderate-vigorous exercise, sedentary behaviour and perceived mental health and cognitive health. All were measured via online self-report questionnaires. Qualitative interviews with 15 students investigated influences on engagement, the acceptability and appropriateness of PEAK, and its mechanisms of behaviour change. Paired t-tests, Wilcoxon Signed-Rank tests and template analysis were used to analyse quantitative and qualitative data, respectively.

Results

On average, 48.4% of students engaged in the recommended frequency of three or more exercise sessions per week. This proportion decreased towards the end of PEAK. Sedentary behaviour significantly decreased from baseline to end-point, and moderate-vigorous exercise significantly increased among students' who were non-exercisers. Mental wellbeing, stress, loneliness, and sense of belonging to the university significantly improved. There were no significant changes in psychological distress. Concentration, memory, and productivity significantly improved. Sixty-eight percent of students remained engaged in one or more components of PEAK at end-point. Qualitative data indicated students found PEAK to be acceptable and appropriate, and that it improved aspects of their capability, opportunity, and motivation to exercise.

Conclusions

Students are receptive to an exercise-based program to support their mental and cognitive health. Students exercise frequency decreased; however, these figures are likely a conservative estimate of students exercise engagement. Students valued the neuroscience-informed approach to motivational and educational content and that the program's goals aligned with their academic goals. Students identified numerous areas PEAK's content and implementation can be optimised, including use of a single digital delivery platform, more opportunities to connect with peers and to expand the content's cultural inclusivity.

Major Depressive Disorder and Gut Microbiota: Role of Physical Exercise

Major depressive disorder (MDD) has a high prevalence and is a major contributor to the global burden of disease. This psychiatric disorder results from a complex interaction between environmental and genetic factors. In recent years, the role of the gut microbiota in brain health has received particular attention, and compelling evidence has shown that patients suffering from depression have gut dysbiosis. Several studies have reported that gut dysbiosis-induced inflammation may cause and/or contribute to the development of depression through dysregulation of the gut-brain axis. Indeed, as a consequence of gut dysbiosis, neuroinflammatory alterations caused by microglial activation together with impairments in neuroplasticity may contribute to the development of depressive symptoms. The modulation of the gut microbiota has been recognized as a potential therapeutic strategy for the management of MMD. In this regard, physical exercise has been shown to positively change microbiota composition and diversity, and this can underlie, at least in part, its antidepressant effects. Given this, the present review will explore the relationship between physical exercise, gut microbiota and depression, with an emphasis on the potential of physical exercise as a non-invasive strategy for modulating the gut microbiota and, through this, regulating the gut-brain axis and alleviating MDD-related symptoms.