Can exercise attenuate the negative effects of long COVID syndrome on brain health?

Nerve Growth Factor and Brain-Derived Neurotrophic Factor in COVID-19

Neurotrophins (NTs) constitute a family of small protein messengers that play a fundamental role in both the central and peripheral nervous systems. In particular, the nerve growth factor (NGF) and the brain-derived neurotrophic factor (BDNF) play a subtle role in the survival, differentiation, and functioning of neuronal populations, as well as in the fine regulation of immune functions. The SARS-CoV-2 infection was characterized by a sequela of symptoms (serious respiratory pathology, inflammatory storm, neurological discomfort, up to the less serious flu-like symptoms), which caused, at the end of 2023, more than 7 million deaths worldwide. Despite the official end of the pandemic, the physical and psychological consequences are currently the object of scientific research, both acute and chronic/long-lasting (Long-COVID-19). Given the multifactorial nature of the outcomes of SARS-CoV-2 infection in adults and children, several studies have investigated the potential involvement of the NGF and BDNF systems in the pathology. This narrative review aims to summarize the most recent evidence on this crucial topic.

Comparative effects of open-skill and closed-skill sports on executive function in university students: a 16-week quasi-experimental study

Introduction

Previous reviews have often concluded that open-skill sports are more effective at enhancing executive function (EF) than closed-skill sports. However, this conclusion may not hold for closed-skill sports with high cognitive demands, such as golf. This study aimed to compare the effects of football (open-skill) and golf (closed-skill) training on enhancing EF in university students.

Method

Using a quasi-experimental, pre-post test design, 63 male participants were assigned to three groups: football (n = 21), golf (n = 21), and a sedentary control group (n = 21). Over 16 weeks of training, the intervention groups engaged in four 90-min training sessions per week, while the control group attended one 80-min physical education class per week. Assessments were conducted before and after the intervention. EFs, including inhibition control and working memory, were assessed using the Flanker task and Corsi-block tapping task, respectively. Cardiovascular fitness (CRF) was measured by the multi-stage fitness test.

Results

The golf group showed significant improvements in inhibition control from pre- to post-intervention (p = 0.02, d = 0.26), while the football and control groups did not exhibit significant changes. Post-intervention comparisons indicated no significant differences in EF performance between the golf and football groups; however, both outperformed the control group (golf, p = 0.002, d = 0.99; football, p = 0.01, d = 0.67). No significant improvement was observed in working memory for any group. Additionally, changes in CRF were not significantly correlated with EF performance.

Conclusion

This study provides preliminary evidence that golf, a closed-skill sport with high cognitive demands, can effectively improve inhibitory control after 16 weeks of training. This improvement is comparable to that observed in football, an open-skill sport. The findings also suggest that the cognitive demands of the sports, rather than improvements in physical fitness, may be primarily responsible for the enhancements in EF.

Effects of conventional versus virtual reality-simulated treadmill exercise on fatigue, cognitive function, and participant satisfaction in post-COVID-19 subjects. A randomized trial

Background/objective

Post-COVID-19 subjects typically experience symptoms of fatigue, cognitive impairment, and sleep difficulty, which can be relieved by conventional aerobic exercise. Virtual Reality (VR) technology to support conventional exercise has recently gained much attention. Therefore, this study aimed to assess the effects of traditional treadmill exercise compared to virtual reality-simulated treadmill exercise on fatigue, cognitive function, sleep quality, and participant satisfaction with the exercise program in post-COVID-19 subjects.

Methods

This single-centered, randomized, parallel-group intervention study was conducted between December 2021 and March 2022. Sixteen of twenty post-COVID-19 subjects completed this study (n1 = 8, n2 = 8). Inclusion criteria were persistent dyspnea/fatigue, mild cognitive problems, and age from 30-60 years. Exclusion criteria were previous severe COVID-19 infection and ICU admission, concomitant respiratory or cardiovascular disease, and musculoskeletal or neurological disease. Eligible subjects were assigned randomly to two groups: a non-VR group that received traditional treadmill aerobic exercise only and a VR group that received treadmill exercise with non-immersive VR. Both groups received moderate-intensity exercise on a treadmill at [50-60 % (peak HR－resting HR) + resting HR] for 30-45 min, three times per week, and for four weeks. The outcome measures were the Chalder Fatigue Scale, Montreal Cognitive Assessment (MoCA) questionnaire, Pittsburgh Sleep Quality Index (PSQI), and participant satisfaction with the exercise program rated on a 5-point Likert scale.

Results

Both groups showed significant improvements in the Chalder Fatigue Scale, the MoCA questionnaire, and the PSQI scores after training compared to baseline (p < 0.05), without significant differences between them (p > 0.05). However, participant satisfaction with the exercise program was significantly higher in the VR group than in the non-VR group (p = 0.037).

Conclusion

A moderate-intensity 4-week treadmill exercise program with and without non-immersive VR may improve fatigue, cognitive function, and sleep quality to the same extent in COVID-19 survivors. However, participant satisfaction with the exercise program could be greater after conventional treadmill training assisted by non-immersive VR than after conventional treadmill training alone in this cohort.

Trial registration

Pan African Clinical Trials Registry, PACTR202311561948428, retrospectively registered.

The Impact of Different Exercise Modes in Fitness and Cognitive Indicators: Hybrid versus Tele-Exercise in Patients with Long Post-COVID-19 Syndrome

The purpose of our study was to obtain evidence that an unsupervised tele-exercise program (TEgroup) via an online platform is a feasible alternative to a hybrid mode of supervised and unsupervised exercise (HEgroup) sessions for improving fitness indexes, respiratory and cognitive functions, and biomarkers of oxidative stress in patients recovering from COVID-19. Forty-nine patients with long post-COVID-19 were randomly divided into two groups (HEgroup: n = 24, age 60.0 ± 9.5 years versus TEgroup: n = 25, age 58.7 ± 9.5 years). For each patient, we collected data from body composition, oxidative stress, pulmonary function, physical fitness, and cognitive function before and after the 12-week exercise rehabilitation program (ERP). Our data showed differences in both groups before and after 12-week ERP on fitness indicators, body composition, and pulmonary function indicators. Our findings demonstrated differences between groups after 12-week ERP on adjustment in the domains of cognitive function (HEgroup increased the "visuospatial" domain: 3.2 ± 1.1 versus 3.5 ± 0.8 score, p = 0.008 and TEgroup increased the "memory" domain: 3.3 ± 1.0 versus 3.8 ± 0.5 score, p = 0.003; after 12-week ERP showed differences between groups in domain "attention" TEgroup: 4.8 ± 1.5 versus HEgroup: 3.6 ± 1.8 score, p = 0.014) and the diffusing capacity for carbon monoxide (HEgroup increased the percent of predicted values at 0.5 ± 32.3% and TEgroup at 26.0 ± 33.1%, p < 0.001). These findings may be attributed to the different ways of learning exercise programs, resulting in the recruitment of different neural circuits.

Efficacy of supervised immersive virtual reality-based training for the treatment of chronic fatigue in post-COVID syndrome: study protocol for a double-blind randomized controlled trial (IFATICO Trial)

BACKGROUND

The treatment of persistent fatigue after COVID-19 infection is complex. On the one hand, it involves maintaining a sufficient level of physical and mental activity to counteract possible degenerative processes of the body and nervous system. On the other hand, physical and mental activities can also lead to worsening of symptoms. Therefore, the challenge in treating Post-COVID fatigue is to stimulate the body and central nervous system in a way that stimulates growth and improvement, but does not overtax individual physical and mental limits. Special training programs try to take these characteristics into account, but often reach their limits. A promising approach is offered by new fitness technologies based on immersive virtual realities that stimulate both body and brain while minimizing physical and psychological stress. The aim of this study is to investigate the efficacy of supervised immersive Virtual Reality (VR)-based activity training compared to conventional activity training for patients with Post-COVID-associated fatigue.

METHODS

In a single centre, individually randomised, prospective, double-blind two-arm exploratory superiority trial with parallel group design, N = 100 patients with persistent fatigue after COVID-19 infection will be recruited. The intervention includes a supervised immersive neuromuscular training (12 sessions of 30 min over 6 weeks) based on a novel VR-exercise device. We will systematically compare the effects of this intervention on Post-COVID-associated fatigue with a supervised conventional activation program of comparable scope without an immersive environment. The primary outcome is the difference between groups in absolute change in the mean fatigue symptom severity measured on the Fatigue Severity Scale (FSS) from baseline to posttreatment assessment. Posttreatment assessment in both groups will be conducted by blinded outcome assessors. At three and six months afterwards, patients are sent self-report questionnaires for follow up. The main analysis will be based on the intention-to-treat principle.

DISCUSSION

To the best of our knowledge, this is the first exploratory study on a supervised immersive neuromuscular training for the treatment of persistent fatigue after COVID-19 infection.

TRIAL REGISTRATION

German register for clinical studies (ID: DRKS00032059) Prospectively registered on June 16th 2023. URL of trial registration.

Characteristics and Treatment of Exercise Intolerance in Patients With Long COVID

The post-acute sequalae of SARS-CoV-2, also known as "Long COVID," is characterized by profound fatigue, impaired functional capacity with post-exertional malaise, orthostatic intolerance, and tachycardia. At least 25-30% of individuals impacted by SARS-CoV-2 will go on to experience the Long COVID syndrome, underscoring the detrimental impact this condition has on society. Although efforts are underway to further understand risk factors for Long COVID and identify strategies to prevent disease development entirely, implementation of treatment strategies is warranted to alleviate symptom burden among those affected. This review provides a rationale for exercise prescriptions tailored to the Long COVID patient based on the pathophysiology underlying this syndrome, as well as the previously demonstrated benefits of exercise training in other similar populations whose clinical manifestations result from cardiac deconditioning. Herein, we discuss methods to tailor exercise protocols, accommodating exercise intolerance and post-exertional malaise that may otherwise limit the ability to participate in a training protocol, as well as data demonstrating that a focused exercise prescription may effectively alleviate symptom burden in these patients. Long COVID results, in large part, from deconditioning, which may result from as little as 20 hr of inactivity. Exercise prescriptions tailored to patients with Long COVID may effectively alleviate symptom burden associated with this condition and in the absence of overt contraindications should be considered in management.