Influence of Physical Activity on Heart Rate Variability in Physically Inactive Adults: A Meta-Analysis

This meta-analysis aimed to examine the influences of physical activity (PA) interventions on heart rate variability (HRV) among healthy but physically inactive adults aged 18 to 65 years old. PubMed, SPORTDiscus and Web of Science online databases were searched in September 2021. The eligibility criteria were: (1) peer-reviewed articles in English; (2) randomized controlled trials; (3) healthy but physically inactive adults aged 18 to 65 years; (4) at least two-week PA intervention; (5) available frequency domain result. The data were extracted to a pre-designed form. The primary outcome of this study was the frequency domain of HRV, which included natural log-transformed total power, low frequency and high frequency (lnTP, lnLF and lnHF), normalized units of LF and HF (LFnu and HFnu), and LF/HF ratio. Pooled estimates of differences and 95% confidence intervals (CI) between the PA intervention group (IG) and control group (CG) were obtained using random-effects models. Six studies were identified in the meta-analysis. There was no significant difference between IG and CG in lnTP (SMD: 0.16, 95% CI: [-0.28, 0.60], p = 0.48), lnLF (SMD: -0.04, 95% CI: [-0.34, 0.42], p = 0.84), lnHF (SMD: 0.03, 95% CI: [-0.23, 0.29], p = 0.81) and LF/HF ratio(MD: -0.21, 95% CI: [-0.48, 0.07], p = 0.14). The results indicated that the LFnu in IG was significantly lower than that in CG (MD: -3.41, 95% CI: [-5.09, -1.73], p \u3c 0.01) while HFnu in IG was significantly higher than that in CG (MD: 3.39, 95% CI: 1.72, 5.07], p \u3c 0.01). The increased HFnu and decreased LFnu after PA interventions indicated a more balanced autonomic nervous system. HRV may be a mediator between PA intervention and other health benefits. The measurements of HRV were inconsistent and increased the variation between studies. The sample sizes of IG or CG in the included studies were small (range from 9 to 26), which limited the power to detect significant differences. This study did not analyze the influence of dose-response and different types of PA interventions due to the limited number of eligible studies. The current evidence suggested that PA interventions benefit HRV in healthy but physically inactive adults aged 18 to 65 years old. Future research with a larger sample size is needed to confirm our findings

The Relationship Between Fundamental Motor Skills and Physical Fitness in Children Aged 7-12 Years

The purpose of this study was to examine the relationship between fundamental motor skills (FMS) and physical fitness (PF) in children aged 7-12 years. The participants were 217 children (50.7% female) from a primary school in Shanghai. The FMS was assessed using Chinese version Test of Gross Motor Development–3 edition (CTGMD-3), which includes 6 locomotor skills and 7 ball skills. PF was measured following China’s national physical health standards for students, which includes BMI, vital capacity, sit and reach, 50m sprint, one-minute rope jumping, one-minute sit-ups and 50m * 8 shuttle run. The weighted score of the 7 tests was calculated to represent the performance of PF. Four participants were assigned into one group and took all tests within a physical education class. Two well-trained graduate assistants performed the tests within one month. Descriptive statistics were computed after checking the normality of the scores of CTGMD-3 and PF. Pearson correlation was used to determine the relationship between FMS and PF. The significance level was set at 0.05. The results showed a significantly positive correlation between the CTGMD-3 score and PF score (r = 0.166, p = 0.014). There was a significantly positive correlation between the score of locomotor skills and PF scores (r = 0.269, p \u3c 0.01). No significant correlation between the score of ball skills and PF score (r = 0.065, p = 0.338) was found. It is concluded that FMS, especially locomotor skills, was associated with PF among children aged 7-12 years. The generalizability of this study was limited since the participants were from one primary school in Shanghai. The small sample size might limit the power of this study. Future research is needed to explore the mechanism underlying the relationship between FMS and PF

Autonomic Modulation, Spontaneous Baroreflex Sensitivity and Fatigue in Young Men After COVID-19

Impaired autonomic modulation and baroreflex sensitivity (BRS) have been reported during and after COVID-19. Both impairments are associated with negative cardiovascular outcomes. If these impairments were to exist undetected in young men after COVID-19, they could lead to negative cardiovascular outcomes. Fatigue is associated with autonomic dysfunction during and after COVID-19. It is unclear if fatigue can be used as an indicator of impaired autonomic modulation and BRS after COVID-19. This study aims to compare parasympathetic modulation, sympathetic modulation, and BRS between young men who had COVID-19 versus controls and to determine if fatigue is associated with impaired autonomic modulation and BRS. Parasympathetic modulation as the highfrequency power of R-R intervals (lnHFR-R), sympathetic modulation as the low-frequency power of systolic blood pressure variability (LFSBP), and BRS as the α-index were measured by power spectral density analysis. These variables were compared between 20 young men who had COVID-19 and 24 controls. Independent t-tests and Mann-Whitney U tests indicated no significant difference between the COVID-19 and the control group in: lnHFR-R, P=0.20; LFSBP, P=0.11, and α-index, P=0.20. Fatigue was not associated with impaired autonomic modulation or BRS. There is no difference in autonomic modulations or BRS between young men who had COVID-19 compared to controls. Fatigue did not seem to be associated with impaired autonomic modulation or impaired BRS in young men after COVID-19. Findings suggest that young men might not be at increased cardiovascular risk from COVID-19-related dysautonomia and impaired BRS

Prospective Association of Daily Steps with Cardiovascular Disease: A Harmonized Meta-Analysis

Background: Taking fewer than the widely promoted “10 000 steps per day” has recently been associated with lower risk of all-cause mortality. The relationship of steps and cardiovascular disease (CVD) risk remains poorly described. A meta-analysis examining the dose–response relationship between steps per day and CVD can help inform clinical and public health guidelines. Methods: Eight prospective studies (20 152 adults [ie, ≥18 years of age]) were included with device-measured steps and participants followed for CVD events. Studies quantified steps per day and CVD events were defined as fatal and nonfatal coronary heart disease, stroke, and heart failure. Cox proportional hazards regression analyses were completed using study-specific quartiles and hazard ratios (HR) and 95% CI were meta-analyzed with inverse-variance–weighted random effects models. Results: The mean age of participants was 63.2±12.4 years and 52% were women. The mean follow-up was 6.2 years (123 209 person-years), with a total of 1523 CVD events (12.4 per 1000 participant-years) reported. There was a significant difference in the association of steps per day and CVD between older (ie, ≥60 years of age) and younger adults (ie, <60 years of age). For older adults, the HR for quartile 2 was 0.80 (95% CI, 0.69 to 0.93), 0.62 for quartile 3 (95% CI, 0.52 to 0.74), and 0.51 for quartile 4 (95% CI, 0.41 to 0.63) compared with the lowest quartile. For younger adults, the HR for quartile 2 was 0.79 (95% CI, 0.46 to 1.35), 0.90 for quartile 3 (95% CI, 0.64 to 1.25), and 0.95 for quartile 4 (95% CI, 0.61 to 1.48) compared with the lowest quartile. Restricted cubic splines demonstrated a nonlinear association whereby more steps were associated with decreased risk of CVD among older adults. Conclusions: For older adults, taking more daily steps was associated with a progressively decreased risk of CVD. Monitoring and promoting steps per day is a simple metric for clinician–patient communication and population health to reduce the risk of CVD

Directly wireless communication of human minds via non-invasive brain-computer-metasurface platform

Brain-computer interfaces (BCIs), invasive or non-invasive, have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings. Inspired by the BCI-based rehabilitation technologies for nerve-system impairments and amputation, we propose an electromagnetic brain-computer-metasurface (EBCM) paradigm, regulated by human’s cognition by brain signals directly and non-invasively. We experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively, which can be further processed and transported by an information metasurface in automated and wireless fashions. Directly wireless communications of the human minds are performed between two EBCM operators with accurate text transmissions. Moreover, several other proof-of-concept mind-control schemes are presented using the same EBCM platform, exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning, wave modulations, and pattern encoding