The effects of physical activity and exercise on brain-derived neurotrophic factor in healthy humans: A review

Effects of 12 weeks of inspiratory muscle training and whole body vibration on the inflammatory profile, BDNF and muscular system in pre-frail elderly women: A randomized controlled trial

AIM

to investigate the effects of the whole body vibration (WBV) and inspiratory muscle training (IMT) on the inflammatory profile and in muscle mass and strength in pre-frail older women.

METHODS

this study was a randomized double-blind trial. Forty two older women aged 60-80 years were randomly allocated to IMT + WBV (G1), IMTsham + WBV (G2) or Sham groups (G3). During 12 weeks G1 received both trainings, whereas G2 received WBV alone and G3 received IMT with a low fixed load and were positioned at the vibratory platform without therapeutic effect. Participants were evaluated before and after the intervention for the following outcomes: Brain-derived neurotrophic factor (BDNF) and inflammatory biomarkers (IB), respiratory (RT) and quadriceps thickness (QT) and diaphragmatic mobility (DM) using muscle ultrasound, body composition (BC) using a bioelectrical impedance scale and inspiratory muscle strength (IMS).

RESULTS

after the training, G1 (114.93 ± 21.29) improved IMS (p<0.005) compared with G2 (91.29 ± 23.10) and G3 (85.21 ± 27.02). There was also a significant improve on time of the DM (p<0.001) and RT (p=0.006) for G1 (8.59 ± 3.55 and 11.11 ± 12.66) compared with G2 (1.05 ± 3.09 and 1.10 ± 10.60) and G3 (0.40 ± 2.29 and -1.85 ± 7.45). BDNF, IB, QT and BC were similar between groups.

CONCLUSIONS

IMT associated with WBV is effective to improve in increasing IMS, RT and DM in pre-frail older women. However, these interventions do not modify BDNF, IB, QT or BC in this population.

Exercise-Induced Central Fatigue: Biomarkers, and Non-Medicinal Interventions

Fatigue, commonly experienced in daily life, is a feeling of extreme tiredness, shortage or lack of energy, exhaustion, and difficulty in performing voluntary tasks. Central fatigue, defined as a progressive failure to voluntarily activate the muscle, is typically linked to moderate- or light-intensity exercise. However, in some instances, high-intensity exercise can also trigger the onset of central fatigue. Exercise-induced central fatigue often precedes the decline in physical performance in well-trained athletes. This leads to a reduction in nerve impulses, decreased neuronal excitability, and an imbalance in brain homeostasis, all of which can adversely impact an athlete's performance and the longevity of their sports career. Therefore, implementing strategies to delay the onset of exercise-induced central fatigue is vital for enhancing athletic performance and safeguarding athletes from the debilitating effects of fatigue. In this review, we discuss the structural basis, measurement methods, and biomarkers of exercise-induced central fatigue. Furthermore, we propose non-pharmacological interventions to mitigate its effects, which can potentially foster improvements in athletes' performances in a healthful and sustainable manner.

Effects of high-intensity interval training combined with dual-site transcranial direct current stimulation on inhibitory control and working memory in healthy adults

Transcranial direct current stimulation (tDCS) and high-intensity interval training (HIIT) have been demonstrated to enhance inhibitory control and working memory (WM) performance in healthy adults. However, the potential benefits of combining these two interventions have been rarely explored and remain largely speculative. This study aimed to explore the effects of acute HIIT combined with dual-site tDCS over the dorsolateral prefrontal cortex (DLPFC, F3 and F4) on inhibitory control and WM in healthy young adults. Twenty-five healthy college students (20.5 ± 1.3 years; 11 females) were recruited to complete HIIT + tDCS, HIIT + sham-tDCS, rest + tDCS, and rest + sham-tDCS (CON) sessions in a randomized crossover design. tDCS or sham-tDCS was conducted after completing HIIT or a rest condition of the same duration. The Stroop and 2-back tasks were used to evaluate the influence of this combined intervention on cognitive tasks involving inhibitory control and WM performance in post-trials, respectively. Response times (RTs) of the Stroop task significantly improved in the HIIT + tDCS session compared to the CON session across all conditions (all p values <0.05), in the HIIT + tDCS session compared to the rest + tDCS session in the congruent and neutral conditions (all p values <0.05), in the HIIT + sham-tDCS session compared to the CON session in the congruent and neutral conditions (all p values <0.05), in the HIIT + sham-tDCS session compared to the rest + tDCS session in the congruent condition (p = 0.015). No differences were found between sessions in composite score of RT and accuracy in the Stroop task (all p values >0.05) and in the 2-back task reaction time and accuracy (all p values >0.05). We conclude that acute HIIT combined with tDCS effectively improved inhibitory control but it failed to yield cumulative benefits on inhibitory control and WM in healthy adults. These preliminary findings help to identify beneficial effects of combined interventions on cognitive performance and might guide future research with clinical populations.

Environmental enrichment: a systematic review on the effect of a changing spatial complexity on hippocampal neurogenesis and plasticity in rodents, with considerations for translation to urban and built environments for humans

Introduction

Hippocampal neurogenesis is critical for improving learning, memory, and spatial navigation. Inhabiting and navigating spatial complexity is key to stimulating adult hippocampal neurogenesis (AHN) in rodents because they share similar hippocampal neuroplasticity characteristics with humans. AHN in humans has recently been found to persist until the tenth decade of life, but it declines with aging and is influenced by environmental enrichment. This systematic review investigated the impact of spatial complexity on neurogenesis and hippocampal plasticity in rodents, and discussed the translatability of these findings to human interventions.

Methods

Comprehensive searches were conducted on three databases in English: PubMed, Web of Science, and Scopus. All literature published until December 2023 was screened and assessed for eligibility. A total of 32 studies with original data were included, and the process is reported in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and checklist.

Results

The studies evaluated various models of spatial complexity in rodents, including environmental enrichment, changes to in-cage elements, complex layouts, and navigational mazes featuring novelty and intermittent complexity. A regression equation was formulated to synthesize key factors influencing neurogenesis, such as duration, physical activity, frequency of changes, diversity of complexity, age, living space size, and temperature.

Conclusion

Findings underscore the cognitive benefits of spatial complexity interventions and inform future translational research from rodents to humans. Home-cage enrichment and models like the Hamlet complex maze and the Marlau cage offer insight into how architectural design and urban navigational complexity can impact neurogenesis in humans. In-space changing complexity, with and without physical activity, is effective for stimulating neurogenesis. While evidence on intermittent spatial complexity in humans is limited, data from the COVID-19 pandemic lockdowns provide preliminary evidence. Existing equations relating rodent and human ages may allow for the translation of enrichment protocol durations from rodents to humans.

The association between levels of brain-derived neurotrophic factor and comorbid depression in patients with cardiovascular disease: The Framingham Heart Study

AIM

The current study aims to investigate the association of serum brain-derived neurotrophic factor (BDNF) levels with symptoms of depression in adults with and without prevalent cardiovascular disease (CVD), an often burdensome comorbidity.

METHODS

This cross-sectional study included participants from FHS (Framingham Heart Study) who had available serum BDNF levels. Depressive symptoms were assessed using the Center for Epidemiological Studies-Depression Scale (CES-D) with a score ≥16 indicating mild to moderate and ≥21 severe depression. Participants taking antidepressant medications were excluded from the study.

RESULTS

Altogether 3716 FHS participants were included in the final analysis (mean age, 64.3 ± 11.5 years; 55% women). After adjusting for potential confounders, greater BDNF levels were associated with reduced severe depression risk (odds ratio [OR], 0.78 [95% CI, 0.64-0.96]; P = 0.016). Among participants with CVD, greater BDNF levels were related to lower risk of depressive symptoms (CES-D ≥ 16 OR, 0.63 [95% CI, 0.45-0.89], P = 0.008; CES-D ≥ 21 OR, 0.49 [95% CI, 0.31-0.76], P = 0.002). The inverse relationship between BDNF and depressive symptom risk was present in women with CVD (CES-D ≥ 16 OR, 0.63 [95% CI, 0.40-0.99], P = 0.047; CES-D ≥ 21 OR, 0.38 [95% CI, 0.21-0.70], P = 0.002) but not in men.

CONCLUSION

Lower serum BDNF levels are associated with a higher risk of depressive symptoms in CVD, particularly among women. These findings implicate BDNF in the complex biological mechanisms that underlie prior associations observed between CVD and depression. To reduce the burden of depression in the large proportion of midlife and older adults with CVD, a better understanding of how BDNF may modify these pathways is merited.

Exploring the Effect of Acute and Regular Physical Exercise on Circulating Brain-Derived Neurotrophic Factor Levels in Individuals with Obesity: A Comprehensive Systematic Review and Meta-Analysis

Obesity is a major global health concern linked to cognitive impairment and neurological disorders. Circulating brain-derived neurotrophic factor (BDNF), a protein crucial for neuronal growth and survival, plays a vital role in brain function and plasticity. Notably, obese individuals tend to exhibit lower BDNF levels, potentially contributing to cognitive decline. Physical exercise offers health benefits, including improved circulating BDNF levels and cognitive function, but the specific impacts of acute versus regular exercise on circulating BDNF levels in obesity are unclear. Understanding this can guide interventions to enhance brain health and counter potential cognitive decline in obese individuals. Therefore, this study aimed to explore the impact of acute and regular physical exercise on circulating BDNF in individuals with obesity. The target population comprised individuals classified as overweight or obese, encompassing both acute and chronic protocols involving all training methods. A comprehensive search was conducted across computerized databases, including PubMed, Academic Search Complete, and Web of Science, in August 2022, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Initially, 98 studies were identified, from which 16 studies, comprising 23 trials, met the selection criteria. Substantial heterogeneity was observed for both acute (I2 = 80.4%) and long-term effects (I2 = 88.7%), but low risk of bias for the included studies. A single session of exercise increased circulating BDNF levels among obese patients compared to the control group (ES = 1.25, 95% CI = 0.19 to 2.30, p = 0.021). However, with extended periods of physical exercise, there was no significant increase in circulating BDNF levels when compared to the control group (ES = 0.49, 95% CI = -0.08 to 1.06, p = 0.089). These findings highlight the need to consider exercise duration and type when studying neurobiological responses in obesity and exercise research. The study's results have implications for exercise prescription in obesity management and highlight the need for tailored interventions to optimize neurotrophic responses. Future research should focus on elucidating the adaptive mechanisms and exploring novel strategies to enhance BDNF modulation through exercise in this population. However, further research is needed considering limitations such as the potential age-related confounding effects due to diverse participant ages, lack of sex-specific analyses, and insufficient exploration of how specific exercise parameters (e.g., duration, intensity, type) impact circulating BDNF.

Effects of Exercise Training Under Hypoxia Versus Normoxia on Cognitive Function in Clinical and Non-Clinical Populations: A Systematic Review and Meta-analysis

OBJECTIVE

To compare the effects of exercise training under hypoxia versus normoxia on cognitive function in clinical and non-clinical populations.

DATA SOURCES

From inception to June 13th, 2022, a systematic search was performed on PubMed, Web of Science, Embase, Scopus, and Cochrane Central Register of Controlled Trials.

STUDY SELECTION

Randomized controlled trials comparing the effects of exercise under hypoxic vs normoxic on cognition in clinical and non-clinical populations were included. The systematic search generated 14,894 relevant studies, of which 12 were finally included.

DATA EXTRACTION

Two reviewers independently extracted data from included studies. Results were expressed as standardized mean difference (SMD). Each included study was assessed using the Cochrane Risk of Bias 1.0 (RoB1.0) tool. Finally, the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system was used to rate the certainty of evidence for each outcome.

DATA SYNTHESIS

Overall, 12 studies with a total of 338 participants met the inclusion criteria. The pooled results suggested that hypoxia exercise had a small but not statistically significant positive effect on overall cognitive function (SMD=0.064, 95% confidence interval (CI): -0.156-0.284, P=.567, very low-certainty evidence), when compared with normoxic exercise. Regarding the domain-specific cognitive functions, there was a medium and significant positive effect on memory (SMD=0.594, 95% CI: 0.068 to 1.120, P=.027, very low-certainty evidence), while effects on visuospatial function (SMD=0.490, 95% CI: -0.030 to 1.010, P=.065, very low-certainty evidence), attention (SMD=0.037, 95% CI: -0.340 to 0.414, P=.847, very low-certainty evidence), executive function (SMD=0.096, 95% CI: -0.268 to 0.460, P=.605, very low-certainty evidence), and processing speed (SMD=-0.145, 95% CI: -0.528 to 0.239, P=.459, very low-certainty evidence) were not statistically significant.

CONCLUSIONS

The current pooled results revealed that hypoxic exercise was related to improved cognitive performance. Nevertheless, exercise under hypoxia did not have a significant advantage in cognitive promotion when compared with exercise under normoxia.

The impact of aerobic endurance training on cognitive performance in schizophrenic inpatients in a clinical routine setting

The primary aim of this study was to investigate the impact of aerobic endurance training in schizophrenic inpatients on cognitive performance in a clinical routine setting. Of secondary interest was the influence on psychopathological symptoms. A total of 31 schizophrenic inpatients were randomly assigned to receive either controlled endurance training or occupational therapy. The experimental group underwent endurance training of 20-30 min each, 3 times per week for a total of up to 22 training sessions. The control group received about 90 min of occupational therapy, 2-3 times per week for up to 22 sessions. Cognitive performance was assessed via an extensive neuropsychological examination before randomization and prior to discharge. Significant improvements in cognitive functions and psychopathology could be shown in both groups. For verbal memory functions (short-term memory, working memory, and learning performance), there was a significant advantage for the aerobic endurance training group. Physical exercise is a feasible, easy-to-implement add-on therapy for schizophrenic patients in a clinical routine setting with positive effects on verbal memory functions. Besides, it seems important to fill the gap between inpatient and outpatient health care, providing physical training supply for this patient group.

Changes of brain-derived neurotrophic factor (BDNF) levels after different exercise protocols: a systematic review of clinical studies in Parkinson's disease

Background: Brain-Derived Neurotrophic Factor (BDNF) serum levels are reduced in patients with Parkinson's Disease (PD). Objectives: This study aimed to assess the effect of exercise intensity, volume and type on BDNF levels in patients with PD. Methods: We searched clinicaltrials.gov, CINAHL, Embase, PubMed, Scopus, Web of Science for both controlled and non-controlled studies in patients with PD, published between 2003 and 2022, which assessed Brain-Derived Neurotrophic Factor before and after different exercise protocols. Exercise intensity was estimated using a time-weighted average of Metabolic Equivalent of Task (MET), while exercise volume was estimated by multiplying MET for the duration of exercise. Exercise types were classified as aerobic, resistance, balance and others. We computed two distinct standardized measures of effects: Hedges' g to estimate differences between experimental and control group in pre-post intervention BDNF changes, and Cohen's d to measure pre-post intervention changes in BDNF values for each study arm. Meta-regression and linear regression were used to assess whether these effect measures were associated with intensity, volume and type. PROSPERO registration number: CRD42023418629. Results: Sixteen studies (8 two-arm trials and 8 single-arm trials) including 370 patients with PD were eligible for the systematic review. Selected studies had a large variability in terms of population and intervention characteristics. The meta-analysis showed a significant improvement in BDNF levels in the exercise group compared to the control group, Hedges' g = 0.70 (95% CI: 0.03, 1.38), with substantial heterogeneity (I2 = 76.0%). Between-group differences in intensity were positively associated with change in BDNF in a subset of 5 controlled studies. In the analysis which included non-controlled studies, intensity and total exercise volume were both positively associated with BDNF change. No difference was found according to exercise type. Conclusion: Exercises of greater intensity may increase BDNF levels in patients with PD, while the role of volume of exercise needs to be further explored.

Physical Activity and Cognitive Functioning

Neuroscience applied to motor activity is a growing area that aims to understand the effects of motor activity on the structures and functions of the Central Nervous System. Attention has been paid to this multidisciplinary field of investigation by the scientific community both because it is of great importance in the treatment of many chronic diseases and because of its potential applications in the Movement Sciences. Motor activity during a developmental age is, in fact, an indispensable tool for the physical and mental growth of children, both able-bodied and disabled. Through movement, individuals can improve their physical efficiency and promote their own better health, establish relationships with the environment and others, express themselves and their emotions, form their identity and develop cognitive processes. This literature review aims, therefore, to highlight how an adequate practice of motor activity offers extraordinary possibilities for everyone in relation to learning, from the perspective of an integral development of the person, and, consequently, can raise the awareness of those involved in the training and growth, especially the youngest, towards the educational value of motor and sports activities. According to this review, and in line with the modern neuroscientific approach toward the relationships between motor activities and cognitive functions, it is possible to claim that hypokinesia tends to inhibit learning. Therefore, it now seems more topical than ever to draw attention to the need to introduce working proposals that integrate brain-based motor activity programs into the school curriculum.

Impact of type, intensity, frequency, duration and volume of physical activity on dementia and mild cognitive impairment in older adults: protocol for a systematic review and meta-analysis

INTRODUCTION

Worldwide, the prevalence of degenerative diseases such as dementia and mild cognitive impairment (MCI) is increasing with population ageing and increasing life expectancy. Both conditions share modifiable risk factors. Physical inactivity is one of these modifiable risk factors, and research points to the protective effect of physical activity on the incidence of dementia and MCI. However, this association tends to change according to type, intensity, frequency, duration and volume of physical activity. Furthermore, it remains unclear which of these characteristics offers the greatest protective effect. Therefore, this study aims to evaluate the impacts of different types, intensities, frequencies, duration and volume of physical activity on dementia and cognitive decline in older adults.

METHODS AND ANALYSIS

The search will be carried out from October 2023, using the following databases: PubMed, Embase, Scopus, CINAHL and Web of Science. Cohort studies with a follow-up time of 1 year or longer that have investigated the incidence of dementia and/or MCI in older adults exposed to physical activity will be included. There will be no limitations on the date of publication of the studies. Studies published in English, Spanish or Portuguese will be analysed. Two researchers will independently screen the articles and extract the data. Any discrepancies will be resolved by a third reviewer. Association measures will be quantified, including OR, HR, relative risk and incidence ratio, with a 95% CI. If the data allow, a meta-analysis will be performed. To assess the methodological quality of the selected studies, the Grading of Recommendations, Assessment, Development and Evaluations instrument, and the Downs and Black instrument to assess the risk of bias, will be used.

ETHICS AND DISSEMINATION

Ethical approval is not required. The results will be submitted for publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42023400411.

Independent and joint associations of aerobic and muscle-strengthening exercise with mental health in adolescents: A cross-sectional analysis before and during COVID-19 using the 2015-2021 National Youth Risk Behavior Survey

PURPOSE

COVID-19 led to social isolation that may have compromised adolescent mental health. This study examined the independent and joint associations of aerobic physical activity (PA) and muscle-strengthening exercise (MSE) with mental health problems in adolescents.

METHODS

Participants were US adolescents who completed the 2015-2021 National Youth Risk Behavior Survey (N = 61,298; 45.7% female). Data were collected between 2015 and 2021 and analyzed in 2023. Outcomes were binary response items asking about feeling sad/hopeless, having difficulty concentrating, remembering, or making decisions, and having a suicidal ideation. Preventive exposure variables were items asking about frequencies of aerobic PA and MSE with responses dichotomized to align with recommendations. Independent and joint associations were examined using robust Poisson regression with covariates selected using double selection lasso. Structural equation models examined the associations treating PA and MSE as continuous predictors and poor mental health as a latent dependent variable.

RESULTS

Meeting either recommendation alone associated with a 4-10% lower prevalence of mental health problems (APR = 0.90-0.96, p < 0.05), and meeting both recommendations associated with a 15%-20% lower prevalence of mental health problems (APR = 0.80-0.85, p < 0.001). Although categorical joint associations were stronger in males (p < 0.05), multiplicative interactions were observed in females using continuous variables for PA and MSE (β = -0.09, p < 0.001).

CONCLUSION

Meeting aerobic PA and MSE recommendations associated with lower prevalence of mental health problems. Participation in MSE below recommended levels may be beneficial for females when combined with aerobic PA. Future research should examine these associations by acquiring contextual information and device-based assessments.

Association between salivary mature brain-derived neurotrophic factor and psychological distress in healthcare workers

INTRODUCTION

Previous studies have suggested association between brain-derived neurotrophic factor (BDNF) and the stress level of workers. However, no studies have investigated the potential of salivary mature BDNF (mBDNF) level as a noninvasive biomarker for psychological distress. This study aimed to explore the reliability of salivary mBDNF as a biomarker for psychological distress in healthcare workers. Furthermore, we examined the relationship between salivary and plasma mBDNF levels and their correlation with age, sex, body mass index (BMI), and exercise habits.

METHODS

Fifty-one healthy healthcare workers (26 men) from the University of Occupational and Environmental Health, Japan, participated in this study. In this cross-sectional study, participants provided demographic information. Psychological distress was assessed using the Kessler 6 (K6). Saliva and blood samples were collected, and mBDNF was measured by ELISA. Spearman's rank correlation coefficient was performed to analyze the relationship between mBDNF (saliva and plasma) and K6. Statistical analyses were conducted using Stata 17.0, and a significance level of p < .05 was applied.

RESULTS

The median K6 score was 1 (interquartile range [IQR]: 0-3). The median (IQR) salivary mBDNF was 1.36 (1.12-1.96) pg/mL, whereas the mean (standard deviation) plasma mBDNF was 1261.11 (242.98) pg/mL. No correlation was observed between salivary and plasma mBDNF concentrations or with the K6 score. Additionally, there were no associations between salivary or plasma mBDNF concentrations and age, sex, or exercise habits. Finally, an association between plasma mBDNF concentration and BMI was found only in univariate analysis.

CONCLUSION

Our findings indicate that salivary mBDNF can be accurately measured noninvasively in healthcare workers. Within our study sample, salivary mBDNF did not demonstrate any correlation with K6 and plasma mBDNF. Future studies with a larger study sample and a diverse study population consisting of healthy participants and patients with psychiatric disorders are warranted.

The impact of resistance training on brain-derived neurotrophic factor and depression among older adults aged 60 years or older: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This systematic review and meta-analysis aimed to investigate the impact of resistance training on brain-derived neurotrophic factor (BDNF) and depression among older adults aged 60 years or older.

METHOD

Four electronic databases were systematically searched.

RESULTS

A total of 11 randomized controlled trials, with a pooled sample of 868 participants, met our inclusion criteria. Meta-analysis demonstrated that resistance training significantly improved circulating BDNF levels (mean difference; MD: 0.73 ng/ml; 95% CI [0.04, 1.42]; p = 0.04). Additionally, resistance training was associated with significant improvements in depression (standardized mean difference; SMD: -0.38; 95% CI [- 0.62, -0.14]; p = 0.002).

DISCUSSION

These findings suggest that resistance training may be an effective intervention for improving BDNF levels and reducing depression symptoms in older adults. Further research is needed to confirm these findings and to investigate the underlying mechanisms.

The relationship between the brain-derived neurotrophic factor and neurocognitive response to physical exercise in individuals with schizophrenia

OBJECTIVE

Physical exercise can improve neurocognition in individuals with schizophrenia, presumably by facilitating neuroplasticity. There is, however, large inter-individual variation in response. The brain-derived neurotrophic factor (BDNF) has been proposed to mediate these effects. The current aim was to investigate the sparsely studied relationship between peripheral resting BDNF and neurocognitive response to physical exercise in individuals with schizophrenia.

METHOD

The current study reports secondary analyses of data from a randomized controlled trial (RCT), ClinicalTrials.gov number 02205684, recently reported according to the CONSORT guidelines. Eighty-two individuals with schizophrenia (mean age 37 ± 14 years old, 61% men) were randomly allocated to high-intensity interval training (HIIT) or a comparison group performing low-intensity active video gaming (AVG). Both interventions consisted of 2 sessions/week for 12 weeks. In previously published primary RCT analyses, HIIT and AVG showed comparable small to moderate improvements in neurocognition. We now address the inter-individual variability in neurocognitive response. We apply mediation and moderation analyses for repeated measures designs (MEMORE) and mixed effects models.

RESULTS

Baseline neurocognition was not significantly correlated with baseline levels of mature BDNF (baseline-mBDNF) or the precursor proBDNF. Nonetheless, baseline-mBDNF, but not baseline proBDNF, moderated the effect of exercise on neurocognition (p = 0.025) and explained 7% of the variance. The neurocognitive improvement increased with increasing baseline-mBDNF values. The moderating effect of baseline-mBDNF remained significant in a more complex model adding the moderating effects of exercise mode, sex, age, duration of illness and baseline VO2max on the outcome (neurocognition). Mean baseline-mBDNF significantly decreased from baseline to post-intervention (p = 0.036), regardless of exercise mode, differing by sex and associated with improved VO2max but not with change in neurocognition. A mediating role of mBDNF on the effect of physical exercise on neurocognition was not supported. Values of proBDNF mainly remained stable from baseline to post-intervention.

CONCLUSION

We found that baseline-mBDNF moderated the effect of physical exercise on neurocognition in individuals with schizophrenia and explained a small part of the inter-individual variation in neurocognitive response. Mean mBDNF decreased from baseline to post-intervention, regardless of exercise mode. A mediating role of mBDNF on the effect of exercise on neurocognition was not supported. The inter-individual variation in neurocognitive response and the complex role of peripheral BDNF in physical exercise is still to be elucidated.

The influence of Tai Chi exercise on the subjective well-being in the aged: the mediating role of physical fitness and cognitive function

This study investigated the effects of Tai Chi exercise on subjective well-being in the aged. The participants were randomly assigned to an experimental group or a control group. The experimental group received 12-week Tai Chi exercise while the control group maintain their original living habits. The participants' subjective well-being, physical fitness, self-control, and executive function were measured at baseline and after 12 weeks of Tai Chi exercise. Results: (1) Tai Chi exercise can positively affect the subjective well-being of the aged (F(1,78) = 37.699, p < 0.001); (2) Tai Chi exercise could affect the subjective well-being in the aged through the independent intermediary of physical fitness (95% CI=[0.115, 0.485]) and self-control (95% CI=[0.109, 0.433]); (3) Tai Chi exercise could indirectly affect the subjective well-being in the aged through the chain mediation of executive function and self-control (95% CI=[0.009, 0.104]). This study provides valuable insights into the potential benefits of Tai Chi exercise for subjective well-being in the aged.

Weekend warrior physical activity pattern is associated with lower depression risk: Findings from NHANES 2007-2018

OBJECTIVE

This study aimed to explore the association between weekend warrior physical activity (PA) pattern and depression risk in American adults.

METHODS

Data of adults (n = 21,125) from NHANES 2007-2018 were used. Adults were categorized into 4 PA patterns (inactive, insufficiently active, weekend warrior, and regularly active) by self-reported PA levels. Participant characteristics in different groups were tested using the Rao & Scott adjusted χ2 test. Multivariate logistic regression models with adjustment for demographics data, behavioral factors and health condition were used to explore the association between PA patterns and depression risk. Finally, interaction analyses were conducted to test if the associations differ by gender, age, race, education level, income level and marital status.

RESULTS

Multivariate logistic regression models showed that insufficiently active, weekend warrior and regularly active adults had 31% (OR: 0.69, 95%CI:0.54-0.88), 57% (OR: 0.43, 95%CI:0.25-0.74) and 54% (OR: 0.46, 95%CI:0.39-0.54) reduced depression risk when compared with inactive adults, respectively. When compared with regularly active adults, inactive (OR: 2.188, 95%CI:1.842-2.600) and insufficiently active (OR: 1.505, 95%CI:1.159-1.955) adults had elevated depression risk, but no significant difference was found between weekend warrior (OR: 0.949, 95%CI:0.538-1.675) and regularly active adults. Moreover, the associations did not differ by demographic variables.

CONCLUSIONS

This study showed that adults who engaged in either regularly active pattern or weekend warrior pattern, experienced lower risk of depression compared to inactive adults. Weekend warrior and regularly active patterns showed similar benefits for lowering depression risk in adults, encouraging adults to take up PA in limited sessions.

Association of muscular strength and targeted proteomics involved in brain health in children with overweight/obesity

Muscular strength has been positively associated with better brain health indicators during childhood obesity. However, the molecular mechanisms underlying the positive impact of muscular strength in brain health are poorly understood. We aimed to study the association of muscular strength with neurology-related circulating proteins in plasma in children with overweight/obesity and to explore the role of cardiorespiratory fitness (CRF) as a confounder. The participants were 86 Caucasian children (10.1 ± 1.1 years old; 41% girls) from the ActiveBrains project. Muscular strength was measured by field and laboratory tests. CRF was assessed with an incremental treadmill test. Olink's technology was used to quantify 92 neurology-related proteins in plasma. Protein-protein interactions were computed using the STRING website. Muscular strength was positively associated with 12 proteins (BetaNGF, CDH6, CLEC10A, CLM1, FcRL2, HAGH, IL12, LAIR2, MSR1, SCARB2, SMOC2, and TNFRSF12A), and negatively associated with 12 proteins (CLEC1B, CTSC, CTSS, gal-8, GCP5, NAAA, NrCAM, NTRK2, PLXNB3, RSPO1, sFRP3, and THY1). After adjustment for CRF, muscular strength was positively associated with eight proteins (BetaNGF, CDH6, CLEC10A, FcRL2, LAIR2, MSR1, SCARB2, and TNFRSF12A) and negatively associated with two proteins (gal-8 and NrCAM). After applying FDR correction, only CLEC10A remained statistically significant. In conclusion, muscular strength was associated with blood circulating proteins involved in several biological processes, particularly anti-inflammatory response, lipid metabolism, beta amyloid clearance, and neuronal action potential propagation. More powered studies are warranted in pediatric populations to contrast or confirm our findings.

Examining the Mechanisms behind Exercise's Multifaceted Impacts on Body Composition, Cognition, and the Gut Microbiome in Cancer Survivors: Exploring the Links to Oxidative Stress and Inflammation

This review focuses on the effects of exercise on various health-related outcomes in cancer survivors, encompassing body composition, cognitive function (including sleep), and gut microbiome health. By analyzing multiple studies, we aimed to summarize the existing evidence and shed light on underlying mechanisms. The findings strongly suggest that exercise serves as a multifaceted non-pharmacological strategy, playing a significant role in improving the overall health of cancer survivors by effectively reducing inflammation and oxidative stress. Exercise plays a crucial role in preventing muscle wasting, diminishing the presence of reactive oxygen species and pro-inflammatory cytokines, and enhancing antioxidant systems. Furthermore, exercise displays notable benefits in terms of executive cognitive functioning and fatigue alleviation, largely attributed to its anti-inflammatory impact on the central nervous system and its ability to induce neurogenesis via growth factors. Additionally, exercise positively influences microbial diversity, reduces gut inflammation, and enhances neurogenesis through the gut-brain axis. Our key findings underscore the reduction of oxidative stress and inflammation as primary mechanisms by which exercise effectively enhances health outcomes in cancer survivors. By delving deeper into these candidate mechanisms, we aim to provide valuable guidance for future research and interventions targeting the symptoms experienced by cancer survivors.

Serum brain-derived neurotrophic factor (BDNF) and self-paced time-trial performance in older untrained men

PURPOSE

This study examined the effect of 12 weeks of concurrent aerobic and resistance training on brain derived neurotrophic factor (BDNF) levels, neuromuscular performance and cerebral oxygenation on self-paced cycling exercise in previously untrained older men.

METHODS

Eight untrained healthy males aged 53-64 years performed a familiarisation and a pre-training self-paced cycling time trial before 12 weeks of exercise training which combined aerobic and resistance exercise. The self-paced cycling time trial comprised a 30 s maximal effort sprint for every 4.5 min of lower intensity pace for a total of 25 min. Upon completion of 12 weeks of training, a comparison of the pre-training trial analysed for serum BDNF, neuromuscular performance, and cerebral oxygenation was undertaken.

RESULTS

Serum BDNF decreased significantly from 10.02 ± 4.63 to 6.96 ± 3.56 ng/ml after 12 weeks of training. There was also attenuated physiological strain for a comparable self-paced cycling performance. Despite positive physiological responses during the time trial pacing strategy was not altered compared with pre training.

CONCLUSION

BDNF decreases following 12 weeks of concurrent training and might reflect neuroplasticity for this type of training stimulus. Exercise training in previously sedentary older men can result in a multitude of physical benefits, which may also confer a neuroprotective effect. However, specific training is required to improve pacing strategies in previously untrained older males.

CLINICAL TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry number ACTRN12622001477718.

[Paracrine and endocrine functions of muscles]

BACKGROUND

Myokines discharged from working muscles are intensively researched in view of rising importance of preventive and secondary preventive effects of the autocrine, paracrine and endocrine functions.

OBJECTIVES

Recording of the current state of knowledge on the paracrine and endocrine effects of myokines and evaluation of training measures to optimize myokine concentration.

METHOD

A selective database-driven literature search was carried out on myostatin, interleukin-6 (IL-6), interleukin-15 (IL-15), irisin, cathepsin B, brain-derived neurotrophic factor (BDNF), meteorin-like and kynurenine for the period 2011 until June 2021. The paracrine and endocrine effects of the myokines are analyzed. Their release after acute physical stress and training is described.

RESULTS

IL-6 and IL-15 act in lipid metabolism and carbohydrate metabolism, IL-6 also in the brain and immune system. Irisin produces a conversion of white to brown adipose tissue ("browning"), so does meteorin-like. Cathepsin B has a central effect. Kynurenine acts indirectly via kynurenic acid in the brain. The secretion of myokines depends on the intensity of physical stress and is modified by training. Prevention of vascular and neurologic diseases, cognitive enhancement and increased immunological function can be reached by setting free myokines during physical activity. Therapeutical use by technologically modified myokines is proposed in metabolic and neurological diseases, immobilization and sarcopenia.

CONCLUSIONS

The current research situation on myokines gives reason to recommend regular muscular activity in addition to the previously evidence-based benefits of sport in order to achieve preventive and therapeutic effects.

The Association Between Objectively-Measured Physical Activity and Cognitive Functioning in Middle-Aged and Older People Living with HIV

Middle-aged and older people living with HIV (PWH) are at higher risk for cognitive impairment and engage in lower levels of physical activity (PA) than seronegative counterparts. Research examining the association between objectively-measured PA and cognitive function in this population is scarce. This cross-sectional study examined the association between accelerometry-measured PA and cognitive functioning among 75 PWH (mean age 55.63). Light PA was the PA variable with the most consistent associations with cognition, with more minutes per week of light PA (performed in bouts of ≥ 10 min) being associated with better executive function, working memory/attention, and speed of processing performance, adjusted for age and current CD4 count. Findings suggest that although middle-aged and older PWH engage in more light than moderate-to-vigorous PA, light PA may be beneficial to cognition. Longitudinal studies are needed to understand PA dose-response associations with cognitive trajectories, cognitive domain specificity of PA effects, and underlying neural mechanisms of PA.

Physical activity for cognitive health promotion: An overview of the underlying neurobiological mechanisms

Physical activity is one of the modifiable factors of cognitive decline and dementia with the strongest evidence. Although many influential reviews have illustrated the neurobiological mechanisms of the cognitive benefits of physical activity, none of them have linked the neurobiological mechanisms to normal exercise physiology to help the readers gain a more advanced, comprehensive understanding of the phenomenon. In this review, we address this issue and provide a synthesis of the literature by focusing on five most studied neurobiological mechanisms. We show that the body's adaptations to enhance exercise performance also benefit the brain and contribute to improved cognition. Specifically, these adaptations include, 1), the release of growth factors that are essential for the development and growth of neurons and for neurogenesis and angiogenesis, 2), the production of lactate that provides energy to the brain and is involved in the synthesis of glutamate and the maintenance of long-term potentiation, 3), the release of anti-inflammatory cytokines that reduce neuroinflammation, 4), the increase in mitochondrial biogenesis and antioxidant enzyme activity that reduce oxidative stress, and 5), the release of neurotransmitters such as dopamine and 5-HT that regulate neurogenesis and modulate cognition. We also discussed several issues relevant for prescribing physical activity, including what intensity and mode of physical activity brings the most cognitive benefits, based on their influence on the above five neurobiological mechanisms. We hope this review helps readers gain a general understanding of the state-of-the-art knowledge on the neurobiological mechanisms of the cognitive benefits of physical activity and guide them in designing new studies to further advance the field.

A Bibliometric Analysis on the Research Trend of Exercise and the Gut Microbiome

This article aims to provide an overview of research hotspots and trends in exercise and the gut microbiome, a field which has recently gained increasing attention. The relevant publications on exercise and the gut microbiome were identified from the Web of Science Core Collection database. The publication types were limited to articles and reviews. VOSviewer 1.6.18 (Centre for Science and Technology Studies, Leiden University, Leiden, the Netherlands) and the R package "bibliometrix" (R Foundation: Vienna, Austria) were used to conduct a bibliometric analysis. A total of 327 eligible publications were eventually identified, including 245 original articles and 82 reviews. A time trend analysis showed that the number of publications rapidly increased after 2014. The leading countries/regions in this field were the USA, China, and Europe. Most of the active institutions were from Europe and the USA. Keyword analysis showed that the relationship between disease, the gut microbiome, and exercise occurs throughout the development of this field of research. The interactions between the gut microbiota, exercise, status of the host's internal environment, and probiotics, are important facets as well. The research topic evolution presents a trend of multidisciplinary and multi-perspective comprehensive analysis. Exercise might become an effective intervention for disease treatment by regulating the gut microbiome. The innovation of exercise-centered lifestyle intervention therapy may become a significant trend in the future.

Exercise-Induced Elevated BDNF Concentration Seems to Prevent Cognitive Impairment after Acute Exposure to Moderate Normobaric Hypoxia among Young Men

Memory impairment, reduced learning ability, decreased concentration, and psychomotor performance can be all signs of deleterious impact of hypoxia on cognitive functioning. In turn, physical exercise can improve performance and enhance cognitive functions. The purpose of this study was to investigate whether the potential positive effects of exercise performed under normobaric hypoxia can counteract the negative effects of hypoxia on cognitive function, and whether these changes correlate with brain-derived neurotrophic factor (BDNF) concentrations. Seventeen healthy subjects participated in a crossover study where they performed two sessions of single breathing bouts combined with moderate intensity exercise under two conditions: normoxia (NOR EX) and normobaric hypoxia (NH EX). To assess cognitive function, Stroop test was applied. There were no significant differences in any part of the Stroop interference test regardless of the conditions (NOR, NH), despite a statistical decrease in SpO2 (p < 0.0001) under normobaric hypoxic conditions. In addition, a statistical increase (p < 0.0001) in BDNF concentration was observed after both conditions. Acute exercise under normobaric hypoxia did not impair cognitive function despite a significant decrease in SpO2. Exercise in such conditions may offset the negative effects of hypoxia alone on cognitive function. This may be related to the significant increase in BDNF concentration and, as a consequence, positively affect the executive functions.

Effects of moderate-intensity aerobic exercise on serum BDNF and motor learning in the upper-limb in patients after chronic-stroke: A randomized, controlled feasibility study with embedded health economic evaluation

BACKGROUND

Brain-derived neurotrophic factor (BDNF) promotes activity-dependent neuroplasticity and is released following aerobic-exercise.

OBJECTIVE

Feasibility and efficacy of 1.Moderate-Intensity Cycle-Ergometer-Training (MI-ET) and 2.Low-Intensity Circuit-Training (LI-CT) on BDNF-serum-concentration in chronic-stroke and consequently efficacy of motor-learning in varying BDNF-concentrations (neuroplasticity being the substrate for motor-learning) via upper-limb robotic-training (RT) in both groups.

METHODS

Randomised-control feasibility-study. 12-week, 3x/week intervention, 17 chronic-stroke-survivors randomized into: (1) MI-ET&RT or (2) LI-CT&RT. Both groups completed 40 mins MI-ET or LI-CT followed by 40 mins RT. Feasibility outcomes: (1) screening and enrollment-rates, (2) retention-rates, (3) adherence: (i) attendance-rates, (ii) training-duration, (4) adverse events. Primary clinical outcomes: 1. serum-BDNF changes pre-post training (immediate) and pre-training basal-levels over 12-weeks (long-term). 2.upper-limb performance with Action-Research-Arm-Test (ARAT). Additionally, feasibility of an embedded health economic evaluation (HEE) to evaluate health-costs and cost-effectiveness.

OUTCOMES

cost-questionnaire return-rates, cost-of-illness (COI) and Health-Utitility-Index (HUI).

RESULTS

21.5% of eligible and contactable enrolled. 10 randomized to MI-ET and 7 to LI-CT. 85% of training-sessions were completed in MI-ET (306/360) and 76.3% in LI-CT-group (165/216). 12-weeks: Drop-outs MI-ET-10%, LI-CT-43%.

CLINICAL OUTCOMES

No significant changes in immediate or long-term serum-BDNF in either group. Moderate-intensity aerobic-training did not increase serum-BDNF post-stroke. Individual but no group clinically-relevant changes in ARAT-scores. HEE outcomes at 12-weeks: 100% cost-questionnaires returned. Group-costs baseline and after treatment, consistently favouring MI-ET group. COI: (1-year-time-frame): MI-ET 67382 SD (43107) Swiss-Francs and LI-CT 95701(29473) Swiss-Francs.

CONCLUSION

The study is feasible with modifications. Future studies should compare high-intensity versus moderate-intensity aerobic-exercise combined with higher dosage arm-training.

A Systematic Review on the Effects of Acute Aerobic Exercise on Neurophysiological, Molecular, and Behavioral Measures in Chronic Stroke

BACKGROUND

A single bout of aerobic exercise (AE) can produce changes in neurophysiological and behavioral measures in healthy individuals and those with stroke. However, the effects of AE-priming effects on neuroplasticity markers and behavioral measures are unclear.

OBJECTIVES

This systematic review aimed to examine the effects of AE on neuroplasticity measures, such as corticomotor excitability (CME), molecular markers, cortical activation, motor learning, and performance in stroke.

METHODS

A literature search was performed in MEDLINE, CINAHL, Scopus, and PsycINFO databases. Randomized and non-randomized studies incorporating acute AE in stroke were selected. Two reviewers independently assessed the risk of bias and methodological rigor of the studies and extracted data on participant characteristics, exercise interventions, and neuroplasticity related outcomes. The quality of transcranial magnetic stimulation reported methods was assessed using a standardized checklist.

RESULTS

A total of 16 studies were found suitable for inclusion. Our findings suggest mixed evidence for the effects of AE on CME, limited to no effects on intracortical inhibition and facilitation and some evidence for modulating brain derived neurotrophic factor levels, motor learning, and cortical activation. Exercise intensities in the moderate to vigorous range showed a trend towards better effects on neuroplasticity measures.

CONCLUSION

It appears that choosing a moderate to vigorous exercise paradigm for at least 20 to 30 minutes may induce changes in some neuroplasticity parameters in stroke. However, these findings necessitate prudent consideration as the studies were diverse and had moderate methodological quality. There is a need for a consensus on an exercise priming paradigm and for good-quality, larger controlled studies.

Association of Physical Inactivity with MRI Markers of Brain Aging: Assessing Mediation by Cardiometabolic and Epigenetic Factors

INTRODUCTION

Cardiometabolic risk factors and epigenetic patterns, increased in physically inactive individuals, are associated with an accelerated brain aging process.

OBJECTIVE

To determine whether cardiometabolic risk factors and epigenetic patterns mediate the association of physical inactivity with unfavorable brain morphology.

METHODS

We included dementia and stroke free participants from the Framingham Heart Study Third Generation and Offspring cohorts who had accelerometery and brain MRI data (n = 2,507, 53.9% women, mean age 53.9 years). We examined mediation by the 2017-revised Framingham Stroke Risk Profile (FSRP, using weights for age, cardiovascular disease, atrial fibrillation, diabetes and smoking status, antihypertension medications, and systolic blood pressure) and the homeostatic model of insulin resistance (HOMA-IR) in models of the association of physical inactivity with brain aging, adjusting for age, age-squared, sex, accelerometer wear time, cohort, time from exam-to-MRI, and season. We similarly assessed mediation by an epigenetic age-prediction algorithm, GrimAge, in a smaller sample of participants who had DNA methylation data (n = 1,418).

RESULTS

FSRP and HOMA-IR explained 8.3-20.5% of associations of higher moderate-to-vigorous physical activity (MVPA), higher steps, and lower sedentary time with higher brain volume. Additionally, FSRP and GrimAge explained 10.3-22.0% of associations of physical inactivity with lower white matter diffusivity and FSRP explained 19.7% of the association of MVPA with lower free water accumulation.

CONCLUSION

Our results suggest that cardiometabolic risk factors and epigenetic patterns partially mediate the associations of physical inactivity with lower brain volume, higher white matter diffusivity, and aggregation of free water in the extracellular compartments of the brain.

Effect of different sport environments on proactive and reactive motor inhibition: A study on open- and closed-skilled athletes via mouse-tracking procedure

This study aimed to investigate the effect of different sport environments (open-and closed-skill sports) on proactive and reactive inhibitory processes as two distinct components of motor inhibition. A mouse-tracking procedure was employed to compare behavioral performance among three groups of participants (tennis players, swimmers and non-athletes) in non-sport-specific cued Go/No-Go (GNG) and Stop Signal Task (SST), which mainly engage proactive and reactive inhibitory control, respectively. Reaction times (RTs), inhibitory failures, and Stop Signal Reaction Times (SSRTs) were measured. To investigate dynamic aspects of inhibitory control, movement trajectories classified as one-shot (absence of trajectory alteration reflected in a steep slope) or non-one-shot (non-linear/multipeaked trajectory, with one or multiple corrections) were analyzed and compared among groups. Results showed no group differences in RTs in Go/No-Go and Stop conditions. SSRTs were significant shorter for the athletes than non-athletes in SST, but no differences emerged for inhibitory failures in cued GNG. During inhibitory failures athletes showed higher proportion of non-one-shot movements than non-athletes. Higher proportion of non-one-shot profiles was observed in cued GNG compared to SST. Finally, no differences between open-and closed-skilled athletes were found in both tasks. Our findings suggest that both proactive and reactive inhibitory controls do benefit from sport practice, but open-and closed-skill sports do not differ in influencing inhibitory processes. Movement profile analysis could be a promising, complementary behavioral analysis to integrate for more fine-grained evaluation and differentiation of inhibitory motor control in athletes, specifically when using GNG tasks.

Preliminary results of the cross-sectional associations of sedentary behavior and physical activity with serum brain-derived neurotrophic factor in adults with coronary heart disease

This is the first study to analyze the association of accelerometer-measured patterns of habitual physical activity (PA) and sedentary behavior (SB) with serum BDNF in individuals with coronary heart disease. A total of 30 individuals (M = 69.5 years; 80% men) participated in this pre-post study that aimed to test a multi-behavioral intervention. All participants underwent standardized measurement of anthropometric variables, blood collection, self-administered survey, and accelerometer-based measurement of PA and SB over seven days. Serum BDNF concentrations were measured using enzyme-linked immunosorbent assay kit. We applied separate multiple linear regression analysis to estimate the associations of baseline SB pattern measures, light and moderate-to-vigorous PA with serum BDNF (n = 29). Participants spent 508.7 ± 76.5 min/d in SB, 258.5 ± 71.2 min/d in light PA, and 21.2 ± 15.2 min/d in moderate-to-vigorous PA. Per day, individuals had 15.5 ± 3.2 numbers of 10-to-30 min bouts of SB (average length: 22.2 ± 2.1 min) and 3.4 ± 1.2 numbers of > 30 min bouts of SB (average length: 43.8 ± 2.4 min). Regression analysis revealed no significant associations between any of the accelerometer-based measures and serum BDNF. The findings of this study did not reveal an association of accelerometer-measured PA and SB pattern variables with serum BDNF in individuals with coronary heart disease. In addition, our data revealed a considerable variation of PA and SB which should be considered in future studies.

Home-Based Exercise to Improve Motor Functions, Cognitive Functions, and Quality of Life in People with Huntington's Disease: A Systematic Review and Meta-Analysis

Exercise in different settings has become a fundamental part of Huntington's disease (HD) management. The aim of this systematic review and meta-analysis was to investigate the effectiveness of home-based exercises (HBE) in HD. Randomized controlled trials (RCTs) investigating the effect of HBE on motor, cognitive, or health-related quality of life (QoL) outcomes in HD were included. Standardized mean difference (SMD), the 95% confidence interval, and p-values were calculated by comparing the outcomes change between HBE and control groups. Seven RCTs met the inclusion criteria. The included RCTs prescribed different types of HBEs, i.e., aerobic strengthening, walking, balance, and fine motor exercises. The HBE protocol length was between 6 and 36 weeks. The meta-analyses showed a significant effect of HBE intervention on motor function measure by Unified Huntington Disease Rating and overall QoL measure by Short Form-36 post-treatment respectively, [SMD = 0.481, p = 0.048], [SMD = 0.378, p = 0.003]. The pooled analysis did not detect significant changes in cognition, gait characteristics, or functional balance scales. The current study shows the positive effect of HBE in HD, especially on motor function and QoL. No significant adverse events were reported. The current results support the clinical effect of HBE intervention on motor function and QoL in HD patients. However, these results should be taken with caution due to the limited available evidence. Well-designed clinical studies that consider the disease severity and stages are required in the future.

Physical inactivity amplifies the negative association between sleep quality and depressive symptoms

Poor sleep quality and physical inactivity are known risk factors for depressive symptoms. Yet, whether these factors differently contribute to depressive symptoms and whether they interact with one another remains unclear. Here, we examined how sleep quality and physical activity influence depressive symptoms in 79,274 adults 50 years of age or older (52.4% women) from the Survey of Health, Aging and Retirement in Europe (SHARE) study. Sleep quality (poor vs. good), physical activity (inactive vs. active), and depressive symptoms (0 to 12 score) were repeatedly collected (7 waves of data collection) between 2004 and 2017. Results showed that sleep quality and physical activity were associated with depressive symptoms. Specifically, participants with poorer sleep quality reported more depressive symptoms than participants with better sleep quality (b = 1.85, 95% CI = 1.83-1.86, p < .001). Likewise, compared to physically active participants, physically inactive participants reported more depressive symptoms (b = 0.44, 95% CI = 0.42-0.45, p < .001). Moreover, sleep quality and physical activity showed an interactive association with depressive symptoms (b = 0.17, 95% CI = 0.13-0.20, p < .001). The negative association between poor sleep quality and higher depressive symptoms was stronger in physically inactive than active participants. These findings suggest that, in adults 50 years of age or older, both poor sleep quality and physical inactivity are related to an increase in depressive symptoms. Moreover, the detrimental association between poor sleep quality and depressive symptoms is amplified in physically inactive individuals.

Acute effects of aerobic versus resistance exercises on cognitive function in individuals with intellectual disability

BACKGROUND

This study compared the acute effects of aerobic (AE) and resistance (RE) exercise on reaction time (RT) and working memory (WM) in individuals with intellectual disability.

METHODS

RT tests and Corsi test for WM were performed before and after three intervention sessions: AE, RE, or control session consisting on watching video.

RESULTS

The RT values decreased significantly (p < .001) after both of AE and RE with higher extend after the RE but did not vary following the control session. Corsi scores increased significantly (p < .001) after AE but not after RE or control session.

CONCLUSIONS

These findings suggest that the effects of acute exercise on cognitive function in individuals with intellectual disability depend on the exercise mode as well as the nature of the cognitive task. The RE seems to be more recommended for RT enhancement whereas only the aerobic one could improve WM in these individuals.

Are COMT Val158Met (rs4680), DRD2 TaqIA (rs1800497), and BDNF Val66Met (rs6265) polymorphisms associated with executive functions performance at rest and during physical exercise?

Executive functions (EFs) encompass a wide array of cognitive processes, which appear to be influenced by genetic variants of the COMT, DRD2/ANKK1, and BDNF polymorphisms. The present study aimed to investigate whether COMT Val158Met (rs4680), DRD2/ANKK1 (rs1800497), and BDNF Val66Met (rs6265) polymorphisms were associated with EFs assessed at rest and during moderate acute physical exercise. Sixty physically active individuals underwent four laboratory visits. First, they filled out the pre-exercise survey, researchers collected their anthropometric data, and then performed a maximal cardiopulmonary exercise test. In the second and third sessions, participants performed EFs test in a randomized order: while the individual was seated on a cycle ergometer without pedaling (i.e., rest condition); and during physical exercise (pedaling for 30 minutes at moderate intensity before starting the EFs test during exercising). On the fourth day, blood samples were drawn. Our results showed that the response time of the COMT Val homozygotes group was significantly shorter than the COMT Met-carrier group [t(39.78) = 2.13, p = .039,d = 0.56] at rest condition. No significant association was found for the other analyses (DRD2/ANKK1 and BDNF). In conclusion, the present study suggests that COMT Val158Met (rs4680) polymorphisms may be associated with EFs at rest condition. However, further studies are needed to validate this association.

Dietary insulin index and insulin load in relation to hypertriglyceridemic waist phenotype and low brain derived neurotrophic factor in adults

Background

The evidence about the relation of the insulinemic potential of food with visceral obesity and brain-derived neurotrophic factor (BDNF) was limited. We aimed to investigate the relation of dietary insulin index (DII) and dietary insulin load (DIL) with hypertriglyceridemic waist phenotype (HTGW) and serum BDNF in Iranian adults.

Methods

This cross-sectional study included 528 middle-aged adults (45.6% women), using a multistage cluster random-sampling method. Dietary intakes were assessed using a validated semi-quantitative 168-item food frequency questionnaire. Blood samples were collected after 12 h of fasting for assessing the serum BDNF and triglyceride concentrations. HTGW was defined as triacylglycerol ≥ 150 mg/dL plus enlarged waist circumference. The values less than the first decile of serum BDNF were considered as the low level.

Results

Individuals in the top tertile of DIL, in comparison to those in the bottom tertile, had higher odds of HTGW in both crude (OR = 1.96, 95% CI: 1.14–3.37) and fully adjusted model (OR = 6.10, 95% CI: 1.58–23.53). However, the relation between DII and odds of HTGW was statistically insignificant in crude (OR = 1.30, 95% CI: 0.78–2.16) and maximally adjusted model (OR = 1.25, 95% CI: 0.65–2.40). After considering confounders, participants in the top tertile of DIL had marginally higher odds of having low BDNF values (OR = 2.00, 95% CI: 0.95–4.21). Nevertheless, the association between DII and odds of low BDNF values was statistically insignificant.

Conclusion

This population-based study demonstrated that adults with higher DIL had significantly higher chance of HTGW phenotype and slightly higher chance for low BDNF level. DII was not associated with HTGW phenotype or BDNF values.

Barking up the wrong biomarker? Correspondence to Shobeiri et al. (2022) "Serum and plasma levels of brain-derived neurotrophic factor in individuals with eating disorders (EDs): a systematic review and meta-analysis"

Despite intensified research efforts into the underlying (neuro-)biology of eating disorders (EDs), only few reliable biomarkers of diagnostic or prognostic value have been identified to date. One promising line of research has focused on the role of peripheral blood-based biomarkers as potential contributors to the complex pathophysiology of EDs. One such candidate marker is brain-derived neurotrophic factor (BDNF), a neurotrophin broadly implicated in neuronal plasticity and food-intake regulation. A growing number of studies have targeted BDNF in EDs; culminating in several recent well-powered and controlled case-control studies, comprehensive meta-analyses, and review articles. In the current correspondence, we aim to put the recent meta-analysis of Shobeiri et al. (J Eat Disord 10(1):105, 2022) into perspective and argue that the finding suggestive of lower BDNF concentrations across individuals with EDs in comparison to healthy controls needs to be interpreted with caution. While this finding is compatible with those from earlier meta-analyses, it may be biased due to several reasons; most notably by the applied study selection procedures, insufficient consideration of influential determinants of BDNF concentrations, and generalization of results across the ED spectrum without sufficient statistical power. Further controlled and comprehensive studies are necessary to establish BDNF as a clinically informative biomarker of EDs.

Effects of different physical activities on brain-derived neurotrophic factor: A systematic review and bayesian network meta-analysis

Background

Emerging evidence suggests that exercise is a simple and effective method for maintaining brain function.

Aims

This review evaluates the effects of five physical exercises, including aerobic training (AT), high-intensity interval training (HIIT), combined training (CT), resistance training (RT), and AT+RT, on the serum level of brain-derived neurotrophic factor (BDNF) in healthy and non-healthy populations.

Methods

We searched CNKI, PubMed, Embase, Scopus, Medline, Web of Science, and Cochrane Library databases to review randomized controlled studies on exercise interventions for BDNF. Quantitative merging analysis of the resulting data using Bayesian network meta-analysis.

Results

The screening and exclusion of the searched literature resulted in the inclusion of 39 randomized controlled trials containing 5 exercise interventions with a total of 2031 subjects. The AT, RT, AT+RT, HIIT, and CT groups (intervention groups) and the CG group (conventional control group) were assigned to 451, 236, 102, 84, 293, and 865 subjects, respectively. The Bayesian network meta-analysis ranked the effect of exercise on BDNF level improvement in healthy and non-healthy subjects as follows: RT > HIIT > CT > AT+RT > AT > CG. Better outcomes were observed in all five intervention groups than in the CG group, with RT having the most significant effect [MD = 3.11 (0.33, 5.76), p < 0.05].

Conclusions

RT at moderate intensity is recommended for children and older adults in the case of exercise tolerance and is effective in maintaining or modulating BDNF levels for promoting brain health.

Systematic Review Registration

https://inplasy.com, INPLASY202250164.

Lower grip strength and insufficient physical activity can increase depressive symptoms among middle-aged and older European adults: a longitudinal study

Objectives

The present study aimed to identify the gender-specific trajectories of grip strength using group-based trajectories, explore the interaction between grip strength and physical activity on depression, and investigate the association of physical activity with the change in depression by different grip strength groups among middle-aged and older European adults.

Methods

A total of 14,098 participants aged 50 years or older from the Survey of Health, Ageing and Retirement in Europe 2007–2019 were included in this study. Group-based trajectory modeling was used to identify the low, middle and high group of grip strength by gender. Generalized estimated equations were fitted to analyze the interaction effect. The data of wave 2-wave 5 and wave 2-wave 7 were chosen to conduct sensitivity analyses.

Results

Significant interactions between grip strength group and physical inactivity were found (x²_interaction = 11.16, P = 0.004). Significant interactions between physical inactivity and time on depression were identified in low (x²_interaction = 27.83, P < 0.001) and moderate (x²_interaction = 23.67, P < 0.001) grip strength, but a similar result was not found in high grip strength (x²_interaction = 4.39, P = 0.495). Participants in the physical inactivity group had higher depression scores in the low and moderate grip strength groups. Sensitivity analyses yield almost similar results.

Conclusions

Grip strength and physical inactivity interact with depression. Lower grip strength and insufficient physical activity can increase depressive symptoms. People with lower grip strength and physical inactivity should pay special attention to the prevention of depression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03392-x.

The Effects of Physical Activity on the Gut Microbiota and the Gut–Brain Axis in Preclinical and Human Models: A Narrative Review

Increasing evidence supports the importance of the gut microbiota (GM) in regulating multiple functions related to host physical health and, more recently, through the gut–brain axis (GBA), mental health. Similarly, the literature on the impact of physical activity (PA), including exercise, on GM and GBA is growing. Therefore, this narrative review summarizes and critically appraises the existing literature that delves into the benefits or adverse effects produced by PA on physical and mental health status through modifications of the GM, highlighting differences and similarities between preclinical and human studies. The same exercise in animal models, whether performed voluntarily or forced, has different effects on the GM, just as, in humans, intense endurance exercise can have a negative influence. In humans and animals, only aerobic PA seems able to modify the composition of the GM, whereas cardiovascular fitness appears related to specific microbial taxa or metabolites that promote a state of physical health. The PA favors bacterial strains that can promote physical performance and that can induce beneficial changes in the brain. Currently, it seems useful to prioritize aerobic activities at a moderate and not prolonged intensity. There may be greater benefits if PA is undertaken from a young age and the effects on the GM seem to gradually disappear when the activity is stopped. The PA produces modifications in the GM that can mediate and induce mental health benefits.

Sedentary behaviour and brain health in middle-aged and older adults: a systematic review

Sedentary behaviour may increase the risk of dementia. Studying physiological effects of sedentary behaviour on cerebral health may provide new insights into the nature of this association. Accordingly, we reviewed if and how acute and habitual sedentary behaviour relate to brain health factors in middle-aged and older adults (≥45 years). Four databases were searched. Twenty-nine studies were included, with mainly cross-sectional designs. Nine studies examined neurotrophic factors and six studied functional brain measures, with the majority of these studies finding no associations with sedentary behaviour. The results from studies on sedentary behaviour and cerebrovascular measures were inconclusive. There was a tentative association between habitual sedentary behaviour and structural white matter health. An explanatory pathway for this effect might relate to the immediate vascular effects of sitting, such as elevation of blood pressure. Nevertheless, due to the foremost cross-sectional nature of the available evidence, reverse causality could also be a possible explanation. More prospective studies are needed to understand the potential of sedentary behaviour as a target for brain health.

Chronic, acute and protocol-dependent effects of exercise on psycho-physiological health during long-term isolation and confinement

Exercise could prevent physical and psychological deteriorations, especially during pandemic times of lock-down scenarios and social isolation. But to meet both, the common exercise protocols require optimization based on holistic investigations and with respect to underlying processes. This study aimed to explore individual chronic and acute effects of continuous and interval running exercise on physical and cognitive performance, mood, and affect and underlying neurophysiological factors during a terrestrial simulated space mission. Six volunteers (three females) were isolated for 120 days. Accompanying exercise training consisted of a continuous and interval running protocol in a cross-over design. Incremental stage tests on a treadmill were done frequently to test physical performance. Actigraphy was used to monitor physical activity level. Cognitive performance, mood (MoodMeter^®), affect (PANAS), brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), vascular-endothelial growth factor (VEGF), and saliva cortisol were investigated prior to, four times during, and after isolation, pre- and post-exercise on two separate days, respectively. As a chronic effect, physical performance increased (and IGF-1 tended) in the course of isolation and training until the end of isolation. Subjective mood and affect state, as well as cognitive performance, basal BDNF and VEGF levels, were well-preserved across the intervention. No acute effects of exercise were detected, besides slower reaction time after exercise in two out of nine cognitive tests, testing sensorimotor speed and memory of complex figures. Consistently higher basal IGF-1 concentrations and faster reaction time in the psychomotor vigilance test were found for the continuous compared to the interval running protocol. The results suggest that 120 days of isolation and confinement can be undergone without cognitive and mental deteriorations. Regular, individual aerobic running training supporting physical fitness is hypothesized to play an important role in this regard. Continuous running exercise seems to trigger higher IGF-1 levels and vigilance compared to interval running. Systematic and prolonged investigations and larger sample size are required to follow up on exercise-protocol specific differences in order to optimize the exercise intervention for long-term psycho-physiological health and well-being.

The Effect of Endurance Training on Serum BDNF Levels in the Chronic Post-Stroke Phase: Current Evidence and Qualitative Systematic Review

Research in modern neurorehabilitation focusses on cognitive and motor recovery programmes tailored to each stroke patient, with particular emphasis on physiological parameters. The objectives of this review were to determine whether a single bout of endurance activity or long-term endurance activity regulates exercise-dependent serum brain-derived neurotrophic factor (BDNF) levels and to evaluate the methodological quality of the studies. To assess the effectiveness of endurance exercise among patients in the chronic post-stroke phase, a systematic review was performed, including searching EBSCOhost, PEDro, PubMed, and Scopus for articles published up to the end of October 2021. The PRISMA 2020 outline was used, and this review was registered on PROSPERO. Of the 180 papers identified, seven intervention studies (comprising 200 patients) met the inclusion criteria. The methodological quality of these studies was evaluated by using the Physiotherapy Evidence Database (PEDro) criteria. The effect of exercise was evaluated in four studies with a single bout of endurance activity, two studies with long-term endurance activity, and one study with a single bout of endurance activity as well as long-term endurance activity. The results of our systematic review provide evidence that endurance exercise might augment the peripheral BDNF concentration in post-stroke individuals.

Brain-Derived Neurotrophic Factor: A Connecting Link Between Nutrition, Lifestyle, and Alzheimer’s Disease

Brain-derived neurotrophic factor (BDNF) involving tropomyosin kinase B and low affinity p75 neurotropin receptors is the most abundant and researched neurotropins in mammal’s brain. It is one of the potential targets for therapeutics in Alzheimer’s disease (AD) owing to its key role in synaptic plasticity. Low levels of BDNF are implicated in the pathophysiology of neurological diseases including AD. However, a healthy lifestyle, exercise, and dietary modifications are shown to positively influence insulin regulation in the brain, reduce inflammation, and up-regulate the levels of BDNF, and are thus expected to have roles in AD. In this review, the relationship between BDNF, mental health, and AD is discussed. Insights into the interrelationships between nutrition, lifestyle, and environment with BDNF and possible roles in AD are also provided in the review. The review sheds light on the possible new therapeutic targets in neurodegenerative diseases.

Effects of exergame and video game training on cognitive and physical function in older adults: A randomized controlled trial

Few studies have simultaneously explored the training effects of exergame and video game. The purpose of this study was to investigate the effects of exergame and video game training on cognitive and physical function in healthy older adults. Eighty-four healthy older adults were randomly assigned to exergame training group, video game training group, and control group. Cognitive and physical function was measured before and after the training. Both training groups improved in verbal memory and aerobic endurance, but the training effects were greater in the exergame training group. The exergame training group also showed significant improvement in lower limb strength and balance. The current study provides evidence that exergame training, incorporating both cognitive engagement and physical activity, exerts greater benefits than cognitively engaging video game training alone. The findings shed lights into the future use of exergame in preventing cognitive and physical function decline in older adults.

Increased serum levels of brain-derived neurotrophic factor following wheelchair half marathon race in individuals with spinal cord injury

Objective: Brain-derived neurotrophic factor (BDNF) has beneficial effects on metabolism as well as the peripheral and central nervous systems. The aim of this study was to assess the response of serum BDNF concentration ([BDNF]s) to wheelchair half marathon race in individuals with spinal cord injury (SCI).Design: Prospective observational study.Setting: The 34th Oita International Wheelchair Marathon Race in Japan.Participants: Nine cervical SCIs (CSCI) and 8 thoracic and lumber SCIs (LSCI) male athletes. Interventions: Wheelchair half-Marathon Race.Outcome measures: [BDNF]s, plasma concentrations of adrenaline ([Ad]p), noradrenaline ([Nor]p), and cortisol ([Cor]p), hematocrit, and platelet count were measured the day before, immediately after, and an hour after the race.Results: [BDNF]s increased significantly immediately after the race in both groups (CSCI; P = 0.0055, LSCI; P = 0.0312) but returned to the baseline levels at one hour after the race. However, [BDNF]s immediately and one hour after the race were significantly higher in LSCI than in CSCI (immediately after the race; P = 0.0037, 1 h after the race; P = 0.0206). Hematocrit and platelet count remained unchanged throughout the study. In LSCI, [Ad]p, [Nor]p and [Cor]p increased significantly immediately after and one hour after the race, compared with the baseline values (P < 0.05). On the other hand, these variables remained unchanged throughout the study in the CSCI.Conclusions: [BDNF]_s increased significantly from the baseline in both LCSI and CSCI but was higher in LSCI than in CSCI immediately after and one hour after the race.

Physical Exercise and Health: A Focus on Its Protective Role in Neurodegenerative Diseases

Scientific evidence has demonstrated the power of physical exercise in the prevention and treatment of numerous chronic and/or age-related diseases, such as musculoskeletal, metabolic, and cardiovascular disorders. In addition, regular exercise is known to play a key role in the context of neurodegenerative diseases, as it helps to reduce the risk of their onset and counteracts their progression. However, the underlying molecular mechanisms have not yet been fully elucidated. In this regard, neurotrophins, such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glia cell line-derived neurotrophic factor (GDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4), have been suggested as key mediators of brain health benefits, as they are involved in neurogenesis, neuronal survival, and synaptic plasticity. The production of these neurotrophic factors, known to be increased by physical exercise, is downregulated in neurodegenerative disorders, suggesting their fundamental importance in maintaining brain health. However, the mechanism by which physical exercise promotes the production of neurotrophins remains to be understood, posing limits on their use for the development of potential therapeutic strategies for the treatment of neurodegenerative diseases. In this literature review, we analyzed the most recent evidence regarding the relationship between physical exercise, neurotrophins, and brain health, providing an overview of their involvement in the onset and progression of neurodegeneration.

The effect of physical exercise on circulating brain-derived neurotrophic factor in healthy subjects: A meta-analysis of randomized controlled trials

OBJECTIVE

To investigate how physical exercise (PE) would affect brain-derived neurotrophic factor (BDNF) in randomized controlled trials (RCTs) of healthy subjects.

METHODS

Seven databases (PubMed, Web of Science, Cochrane, Embase, PsycINFO, CINAHL, SPORTDiscus) were searched for RCTs assessing the effects of PE on serum and/or plasma BDNF until December 18, 2021. Meta-analysis was performed by random-effects method with standardized mean difference (SMD) and 95% confidence intervals (CIs). Subgroup analysis and meta-regression analysis were conducted to investigate the potential source of heterogeneity. Trim and fill method, and leave-one-out cross-validation were conducted.

RESULTS

Eventually, 21 articles, involving 809 participants, were included in the meta-analysis. Overall, both acute (5 trials, SMD: 1.20, 95% CI: 0.36 to 2.04, p = .005) and long-term (17 trials, SMD: 0.68, 95% CI: 0.27 to 1.08, p = .001) PE had significant positive effects on BDNF levels. Via subgroup analysis, studies of long-term PE with larger sample sizes, female participants, participants older than 60 years, and aerobic exercise contributed to a more pronounced improvement on BDNF levels than that found when all studies were combined.

CONCLUSION

Both acute and long-term PE had significant positive effects on circulating BDNF in healthy subjects. This review suggests that acute exercise and long-term aerobic exercise are powerful forms of PE to enhance neurotrophic effect, especially for female subjects or subjects over 60 years.

Cognitive Improvement After Aerobic and Resistance Exercise Is Not Associated With Peripheral Biomarkers

The role of peripheral biomarkers following acute physical exercise on cognitive improvement has not been systematically evaluated. This study aimed to explore the role of peripheral circulating biomarkers in executive performance following acute aerobic and resistance exercise. Nineteen healthy males completed a central executive (Go/No-Go) task before and after 30-min of perceived intensity matched aerobic and resistance exercise. In the aerobic condition, the participants cycled an ergometer at 40% peak oxygen uptake. In the resistance condition, they performed resistance exercise using elastic bands. Before and after an acute bout of physical exercise, venous samples were collected for the assessment of following biomarkers: adrenaline, noradrenaline, glucose, lactate, cortisol, insulin-like growth hormone factor 1, and brain-derived neurotrophic factor. Reaction time decreased following both aerobic exercise and resistance exercise (p = 0.04). Repeated measures correlation analysis indicated that changes in reaction time were not associated with the peripheral biomarkers (all p &gt; 0.05). Accuracy tended to decrease in the resistance exercise condition (p = 0.054). Accuracy was associated with changes in adrenaline [rrm(18) = −0.51, p = 0.023], noradrenaline [rrm(18) = −0.66, p = 0.002], lactate [rrm(18) = −0.47, p = 0.035], and brain-derived neurotrophic factor [rrm(17) = −0.47, p = 0.044] in the resistance condition. These findings suggest that these peripheral biomarkers do not directly contribute to reduction in reaction time following aerobic or resistance exercise. However, greater sympathoexcitation, reflected by greater increase in noradrenaline, may be associated with a tendency for a reduction in accuracy after acute resistance exercise.