The physiologic mechanisms by which the four activities of sleep, sedentary behavior, light-intensity physical activity, and moderate-to-vigorous physical activity (MVPA) affect health are related, ...but these relationships have not been well explored in adults. Research studies have commonly evaluated how time spent in one activity affects health. Because one can only increase time in one activity by decreasing time in another, such studies cannot determine the extent that a health benefit is due to one activity versus due to reallocating time among the other activities. For example, interventions to improve sleep possibly also increase time spent in MVPA. If so, the overall effect of such interventions on risk of premature mortality is due to both more MVPA and better sleep. Further, the potential for interaction between activities to affect health outcomes is largely unexplored. For example, is there a threshold of MVPA minutes per day, above which adverse health effects of sedentary behavior are eliminated? This article considers the 24-h Activity Cycle (24-HAC) model as a paradigm for exploring inter-relatedness of health effects of the four activities. It discusses how to measure time spent in each of the four activities, as well as the analytical and statistical challenges in analyzing data based on the model, including the inevitable challenge of confounding among activities. The potential usefulness of this model is described by reviewing selected research findings that aided in the creation of the model and discussing future applications of the 24-HAC model.
Exposure to PM2.5 increases blood pressure (BP) and cardiovascular morbidity and mortality. We conducted a randomized controlled panel study in Shijiazhuang, China among 55 healthy college students ...randomly assigned to either the control (CON) or SPORTS group with intervention of 2000 m jogging in 20 min for 3 times in 4 days, and 3-round health examinations from November 15, 2020 to December 6, 2020. We aimed to evaluate whether moderate physical activity (PA) protected BP health against PM2.5 exposure and explore potential mechanisms through myokines and inflammation. Individual PM2.5 exposure was calculated based on outdoor and indoor PM2.5 concentration monitoring data as well as time-activity diary of each subject. In the CON group, the exposure-response curve for SBP was linear with a threshold concentration of approximately 31 μg/m3, while an increment of SBP level was 4.38 mm Hg (95%CI: 0.17 mm Hg, 8.59 mm Hg) at lag03 for each 10-μg/m3 increase in PM2.5, using linear mixed-effect models. For inflammatory indicators, PM2.5 exposure was associated with significant increases in eosinophil counts and proportion in CON group, but decreases in MCP-1 and TNF-α in SPORTS group. Meanwhile, higher myokines including CLU and IL-6 were observed in SPORTS group compared to the CON group. Further mediation analyses revealed that eosinophil counts mediated the elevated BP in CON group, whereas MCP-1 and TNF-α were also crucial mediating cytokines for the SPORTS group, as well as CLU and IL-6 acted as mediators on BP and inflammation indicators in SPORTS group. This study suggests that moderate PA could counteract the elevated BP induced by PM2.5 exposure via myokines-suppressed inflammation pathways.
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•PM2.5 exposure was associated with elevated SBP.•Moderate physical activity suppressed elevated SBP associated with PM2.5 exposure.•Moderate PA suppressed inflammation associated with PM2.5 exposure.•Myokines mediated suppression of moderate PA on elevated SBP associated with PM2.5.•Myokines mediated suppression of moderate PA on inflammatory associated with PM2.5.
Few studies explored the association of different type of physical activity with all-cause mortality in hypertension (HBP) participants. A retrospective cohort analysis was performed using National ...Health and Nutrition Examination Survey (NHANES) data to explore association of moderate-intensity physical activity (MPA), vigorous-intensity physical activity (VPA), sedentary behavior with mortality in HBP individuals. Among 10,913 HBP participants followed for a median of 6.2 years, VPA was not associated with a reduction in all-cause mortality compared to participants without VPA in multivariate Cox survival analysis. MPA was linked to lower all-cause mortality at durations of 0-150 min/week (HR, 0.72; 95% CI 0.58-0.88), 150-300 min/week (HR, 0.71; 95% CI 0.52-0.96), and > 300 min/week (HR, 0.61; 95% CI 0.49-0.77) compared to no MPA. Sedentary behavior of 6-8 h/day (HR, 1.35; 95% CI 1.15-1.59) and > 8 h/day (HR, 1.55; 95% CI 1.34-1.79) were associated with increased mortality risk versus < 6 h/day. Further research is needed to explore whether VPA can improve outcomes for HBP individuals and to determine the optimal duration of VPA.MPA is linked to lower mortality risk, indicating its potential as the best physical activity intensity for HBP individuals.
Adolescents' engagement in daily physical activity brings multiple benefits, including reduction in obesity, improvement of mental health, and enhancement of cognitive function (CF). While prior ...studies have examined the link between physical activity and cognitive function, little is known regarding the extent to which this relationship is shaped by health and wellbeing factors. This study examines how subjective wellbeing (SWB) and general health (GH) mediate the relationship between adolescents' physical activity and cognitive function.
This study estimates a parallel structural equation model using the Program for International Student Assessment 2018 dataset. Specifically, a total of 63,228 15-year-old subjects in nine countries/economies satisfied the study inclusion criteria, including in Bulgaria, Georgia, Hong Kong, Ireland, Mexico, Panama, Serbia, Spain, and United Arab Emirates. Frequency of moderate physical activity (MPA, ≥3.0 Metabolic Equivalent Task) was reported weekly; SWB and GH were assessed using an internationally validated multi-item standardized questionnaire. SWB was measured by students' self-evaluated satisfaction with their health, life, and schooling. GH was measured by students' physical health and mental health status. Cognitive function (CF) was modeled as a latent function consisting of plausible values derived using item response theory on reading, mathematics, and science achievement tests.
Findings indicated that increase in weekly MPA was positively associated with higher levels of SWB (
< .001), GH (
< .001), and CF (
< .001) among the study subjects. Parallel mediation analyses revealed that more frequent weekly MPA had relatively large direct effects (
< .001) on CF, and indirect effects channeling through improvements in SWB and GH were non-trivial (
< .001). Heterogeneity results showed that boosts to CF, associated with MPA, were larger for mathematics and science than for reading (
< .001).
This study used a large-scale international dataset to show that the positive relationship observed between MPA and CF among adolescents was robust, and that SWB and GH were two critical mediators through which physical activity positively bolster CF.
The aim of this study was to examine the associations of fitness and physical activity with academic achievement in children with overweight/obesity. A total of 106 (10.0 ± 1.1y, 61 boys) children ...participated. The fitness components were assessed by field and laboratory-based tests. Physical activity was measured via accelerometry. The academic achievement was assessed by a standardised test and school-grades. Field-based cardiorespiratory fitness was associated with language skills (ß-standardised- ranging from 0.281 to 0.365, p < 0.01). The field-based muscular strength was associated with grade point average, natural and social sciences, and foreign language (ß = 0.280-0.326, all p ≤ 0.01). Speed-agility was associated with some language-related skills (ß = 0.325-0.393, all p ≤ 0.01). The laboratory-based muscular strength also showed an association with mathematics skills (ß = 0.251-0.306, all p ≤ 0.01). Physical activity did not show significant association with academic achievement (p > 0.01). Overall, the significant associations observed for muscular strength and speed/agility were attenuated and disappeared in many cases after additional adjustments for body mass index and cardiorespiratory fitness, indicating that these associations are inter-dependent. Our study contributes by indicating that other fitness components apart from cardiorespiratory fitness, such as muscular strength and speed-agility, are positively associated with academic achievement. However, these associations appear to be dependent on body mass index and cardiorespiratory fitness.
Physical activity (PA) and telomeres both contribute to healthy aging and longevity. To investigate the optimal dosage of various PA for longevity and the role of telomere length in PA and mortality.
...Prospective cohort study.
A total of 333,865 adults (mean age of 56 years) from the UK Biobank were analyzed.
Walking, moderate PA (MPA), and vigorous PA (VPA) were self-reported via questionnaire, and leukocyte telomere length (LTL) was measured. Cox proportional hazards regression was used to predict all-cause mortality risk. A flexible parametric Royston-Parmar survival model was used to estimate life expectancy.
During a median follow-up of 13.8 years, 19,789 deaths were recorded. Compared with the no-walking group, 90 to 720 minutes/week of walking was similarly associated with 27% to 31% of lower mortality and about 6 years of additional life expectancy. We observed nearly major benefits for mortality and life expectancy among those meeting the PA guidelines 151-300 minutes/wk for MPA: hazard ratio (HR) 0.80, 95% CI 0.75-0.85, 3.40-3.42 additional life years; 76-150 minutes/wk for VPA: HR 0.78, 95% CI 0.75-0.82, 2.61 years (2.33-2.89) vs the no-PA group. Similar benefits were also observed at 76-150 and 301-375 minutes/wk of MPA (18%-19% lower mortality, 3.20-3.42 gained years) or 151-300 minutes/wk of VPA (20%-26% lower mortality, 2.41-2.61 gained years). The associations between MPA, VPA, and mortality risk were slightly mediated by LTL (≈1% mediation proportion, both P < .001).
Our study suggests a more flexible range of PA than the current PA guidelines, which could gain similar benefits and is easier to achieve: 90 to 720 minutes/wk of walking, 75 to 375 minutes/wk of MPA, and 75 to 300 minutes/wk of VPA. Telomeres might be a potential mechanism by which PA promotes longevity.
Few studies have examined whether maintaining moderate or vigorous physical activity (PA) reduces the risk of low back pain in older people. This study aimed to examine the magnitude of the ...associations of changes in PA on the risk of low back pain at 4 years of follow-up. We analyzed 4,882 participants in the English Longitudinal Study of Ageing who were initially free from low back pain (mean age, 65.6 ± 8.9 years at baseline). Self-reported PA, which was assessed at wave 6 (2012-2013) and wave 7 (2014-2015), was used as the exposure. The PA of the respondents was categorized into "no PA at all," "up to moderate PA," and "up to vigorous PA" groups. Self-reported moderate/severe low back pain assessed at 4 years of follow-up (2016-2017) was used as the outcome. Maintaining moderate (relative risk RR, 0.59; 95% confidence interval CI, 0.36-0.99) or vigorous (RR, 0.46; 95% CI, 0.27-0.77) PA at least 1-3 times a month was negatively associated with prevalence of low back pain compared with no PA at all. Interventions for maintaining either moderate or vigorous PA might be beneficial in preventing the incidence of low back pain in the older population. PERSPECTIVE: This study examined the magnitude of the association between changes in physical activity over time and the risk of low back pain. The findings suggest that encouraging people to maintain at least moderate physical activity over 2 years is useful for reducing the risk of low back pain at 4 years of follow-up.
Habitual physical activity improves heart functions and parasympathetic tone; Karate training is considered as a moderate physical activity with rhythmical breathing patternology. Heart rate ...variability (HRV) is an electrophysiological tool which measures cardio autonomic homeostasis; is used in the present study as an indirect marker to measure neurocognitive development with karate training. The aim of the present study was to find out the impact of regular karate training on cardiac autonomic responses through Heart Rate Variability (HRV) between karate players and age-sex matched active controls. A total of 30 male school-going children were evaluated; fifteen were experienced male karate practitioners (9.5±1.26 years) and fifteen controls (10.6±1.57 years). The time and frequency domain measures of HRV were taken into account after check for normality distribution, followed by t-test for comparison of Mean±SD. Frequency domain measures; low frequency normalized unit (LF nu) and low frequency is to high frequency ratio (LF/HF ratio) both showed significant reduction in the karate group which quantified sympathetic disposition while High frequency normalized units (HF nu) reflected a significant rise and it predicted increase in parasympathetic tone. Karate practitioners show higher HRV measures and more involvement of the parasympathetic nervous system which help in stress resilience and improved recovery time. This training if performed regularly from an early age can improve cardiac health which is very pertinent in the present times.
Activity-dependent neuroprotective protein (ADNP) is a neuroprotective protein essential for embryonic development, proper brain development, and neuronal plasticity. Its mutation causes the ...autism-like ADNP syndrome (also called the Helsmoortel-Van der Aa syndrome), characterized by neural developmental disorders and motor dysfunctions. Similar to the ADNP syndrome, the
haploinsufficient mouse shows low synapse density, leading to motor and cognitive ability delays. Moderate physical activity (PA) has several neuroprotective and cognitive benefits, promoting neuronal survival, differentiation, neurogenesis, and plasticity. Until now, no study has investigated the effect of moderate exercise on ADNP expression and distribution in the rat brain. The aim of the current investigation was to study the effects of moderate exercise on the ADNP expression and neuronal activation measured by the microtubule protein β-Tubulin III. In pursuit of this objective, twenty-four rats were selected and evenly distributed into two categories: sedentary control rats and rats exposed to moderate physical activity on a treadmill over a span of 12 weeks. Our results showed that moderate PA increases the expression of ADNP and β-Tubulin III in the dentate gyrus (DG) hippocampal region and cerebellum. Moreover, we found a co-localization of ADNP and β-Tubulin III in both DG and cerebellum, suggesting a direct association of ADNP with adult neuronal activation induced by moderate PA.
Variability exists in children's activity patterns due to the association with environmental, social, demographic, and inter-individual factors. This study described accelerometer assessed physical ...activity patterns of high and low active children during segmented school week days whilst controlling for potential correlates.
Two hundred and twenty-three children (mean age: 10.7 ± 0.3 yrs, 55.6% girls, 18.9% overweight/obese) from 8 north-west England primary schools wore ActiGraph GT1M accelerometers for 7 consecutive days during autumn of 2009. ActiGraph counts were converted to minutes of moderate (MPA), vigorous (VPA) and moderate-to-vigorous (MVPA) physical activity. Children were classified as high active (HIGH) or low active (LOW) depending on the percentage of week days they accumulated at least 60 minutes of MVPA. Minutes spent in MPA and VPA were calculated for school time and non-school time and for five discrete school day segments (before-school, class time, recess, lunchtime, and after-school). Data were analysed using multi-level modelling.
The HIGH group spent significantly longer in MPA and/or VPA before-school, during class time, lunchtime, and after-school (P < .05), independent of child and school level factors. The greatest differences occurred after-school (MPA = 5.5 minutes, VPA = 3.8 minutes, P < 0.001). MPA and VPA were also associated with gender, BMI z-score, number of enrolled children, playground area per student, and temperature, depending on the segment analysed.The additive effect of the segment differences was that the HIGH group accumulated 12.5 minutes per day more MVPA than the LOW group.
HIGH active children achieved significantly more MPA and VPA than LOW active during four of the five segments of the school day when analyses were adjusted for potential correlates. Physical activity promotion strategies targeting low active children during discretionary physical activity segments of the day, and particularly via structured afterschool physical activity programs may be beneficial.
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