Sedentary Group Research Articles

Comparison of face mask effects on cardiorespiratory responses between physically active and sedentary individuals.

Alterations caused by face masks on physiological responses vary among different population groups. This study aimed to investigate whether physically active and sedentary individuals respond differently to face mask use during exercise. Sixteen healthy college students were divided into two groups: Physically active group (N.=10; 26.50±2.80 years) and Sedentary group (N.=6; 26.33±2.81 years). They performed three maximal cardiopulmonary exercise test (CPET)s following the Bruce protocol: one without a face mask (NON), one with a surgical mask (SUR) and one with a cloth mask (CLO). Cardiorespiratory parameters and heart rate were monitored continuously during the test. Blood pressure, oxygen saturation and lactate level were measured immediately before and after exertion. Significant differences were found between the Physically active and the Sedentary group in peak VO<inf>2</inf> (VO<inf>2peak</inf>) in NON (P=0.030). However, this difference disappeared when the face masks were used. Furthermore, VO<inf>2</inf>/kg (P=0.002) and METs (P=0.002) decreased significantly at the respiratory compensation point (RCP) only in the Physically active group with face masks. No significant differences were found between the two groups for exercise time, lactate level and dyspnea (P>0.05). The decrease in exercise tolerance and cardiorespiratory responses, particularly VO<inf>2peak</inf>, due to face mask use was greater in physically active individuals compared to sedentary individuals. Population group characteristics should be considered when adapting face masks to daily life.

Exercise Preconditioning Preserves Cardiac Function and Enhances Cardiac Recovery Following Dobutamine Stimulation in Doxorubicin-Treated Rat Hearts.

Exercise preconditioning has been shown to protect against doxorubicin (DOX)-induced cardiac dysfunction when hearts are maintained under resting conditions. However, it is unclear whether this exercise-induced protective effect is maintained when the heart is challenged with the β 1 -adrenergic receptor agonist dobutamine (DOB), which mimics acute exercise stress. Fischer 344 rats were randomly assigned to sedentary (SED) or voluntary wheel running (WR) groups for 10 weeks. At week 11, rats were treated with either 15 mg/kg DOX or saline. Five days later, ex vivo cardiac function was assessed using an isolated working heart model at baseline, during the infusion of 7.5 μg·kg -1 ·min -1 DOB, and during recovery. DOB infusion significantly increased left ventricular developed pressure (LVDP), maximal (dP/dt max ) and minimal (dP/dt min ) rate of left ventricular pressure development, and heart rate in all groups ( P < 0.05). SED + DOX also showed a lower baseline and recovery LVDP than WR + DOX (83 ± 12 vs. 109 ± 6 mm Hg baseline, 76 ± 11 vs. 100 ± 10 mm Hg recovery, P < 0.05). WR + DOX showed higher dP/dt max and lower dP/dt min when compared with SED + DOX during DOB infusion (7311 ± 1481 vs. 5167 ± 1436 mm Hg/s and -4059 ± 1114 vs.-3158 ± 1176 mm Hg/s, respectively). SED + DOX dP/dt max was significantly lower during baseline and during recovery when compared with all other groups ( P < 0.05). These data suggest that exercise preconditioning preserved cardiac function after DOX exposure even when the heart is challenged with DOB, and it appeared to preserve the heart's ability to recover from this functional challenge.

Exercise as a promising alternative for sciatic nerve injury pain relief: a meta-analysis.

The efficacy of drug therapies in managing neuropathic pain is constrained by their limited effectiveness and potential for adverse effects. In contrast, exercise has emerged as a promising alternative for pain relief. In this study, we conducted a systematic evaluation of the therapeutic impact of exercise on neuropathic pain resulting from sciatic nerve injury in rodent models. The PubMed, Embase, and Web of Science databases were retrieved before April 2024. A series of studies regarding the effect of treadmill, swimming, wheel and other exercises on neuropathic pain induced by sciatic nerve injury in rats and mice were collected. Using predefined inclusion criteria, two researchers independently performed literature screening, data extraction, and methodological quality assessment utilizing SYRCLE's risk of bias tool for animal studies. Statistical analysis was conducted using RevMan 5.3 and STATA 12.0 analysis software. A total of 12 relevant academic sources were included in the analysis of controlled animal studies, with 133 rodents in the exercise group and 135 rodents in the sedentary group. The meta-analysis revealed that exercise was associated with a significant increase in paw withdrawal mechanical threshold [Standard Mean Difference (SMD) = 0.84, 95% confidence interval (CI): 0.28-1.40, p = 0.003] and paw withdrawal thermal latency (SMD = 1.54, 95%CI: 0.93-2.15, p < 0.0001) in rats and mice with sciatic nerve injury. Subgroup analyses were conducted to evaluate the impact of exercise duration on heterogeneity. The results showed that postoperative exercise duration ≤3 weeks could significantly elevate paw withdrawal mechanical threshold (SMD = 1.04, 95% CI: 0.62-1.46, p < 0.00001). Postoperative exercise duration ≤4 weeks could significantly improve paw withdrawal thermal latency (SMD = 1.93, 95% CI:1.19-2.67, p < 0.00001). Exercise represents an effective method for improving mechanical and thermal hypersensitivity resulting from sciatic nerve injury in rodents. Factors such as pain models, the initiation of exercise, the type of exercise, and the species of rodent do not significantly impact the development of exercise-induced hypoalgesia. However, the duration of postoperative exercise plays a crucial role in the onset of exercise-induced hypoalgesia.

Moderate-Intensity Treadmill Exercise Regulates GSK3α/β Activity in the Cortex and Hippocampus of APP/PS1 Transgenic Mice.

Physical exercise has been shown to be beneficial for individuals with Alzheimer's disease (AD), although the underlying mechanisms are not fully understood. Six-month-old Amyloid precursor protein/Presenilin 1 (APP/PS1) transgenic (Tg) mice and wild-type (Wt) mice were randomly assigned to either a sedentary group (Tg-Sed, Wt-Sed) or an exercise group (Tg-Ex, Wt-Ex) undertaking a 12-week, moderate-intensity treadmill running program. Consequently, all mice were tested for memory function and amyloid β (Aβ) levels and phosphorylation of tau and protein kinase B (Akt)/glycogen synthase kinase-3 (GSK3) were examined in tissues of both the cortex and hippocampus. Tg-Sed mice had severely impaired memory, higher levels of Aβ, and increased phosphorylation of tau, GSK3α tyrosine279, and GSK3β tyrosine216, but less phosphorylation of GSK3α serine21, GSK3β serine9, and Akt serine473 in both tissues than Wt-Sed mice in respective tissues. Tg-Ex mice showed significant improvement in memory function along with lower levels of Aβ and less phosphorylation of tau (both tissues), GSK3α tyrosine279 (both tissues), and GSK3β tyrosine216 (hippocampus only), but increased phosphorylation of GSK3α serine21 (both tissues), GSK3β serine9 (hippocampus only), and Akt serine473 (both tissues) compared with Tg-Sed mice in respective tissues. Moderate-intensity aerobic exercise is highly effective in improving memory function in 9-month-old APP/PS1 mice, most likely through differential modulation of GSK3α/β phosphorylation in the cortex and hippocampus.

Gestational physical activity alters offspring brain APP processing in an age-specific manner.

Maternal exercise is beneficial for offspring brain development. Amyloid precursor protein (APP) influences neurogenesis and synaptic plasticity. Cleavage products of APP are implicated in the proliferation of neural progenitor cells and neuronal network development. Our study aimed to investigate differences in APP processing in active or sedentary offspring of dams who were exposed to voluntary wheel running with and without a western diet throughout gestation. Female Wistar rats (7-8 weeks old) were fed a normal chow or western diet and randomized into voluntary wheel run or sedentary conditions. Dams returned to sedentary conditions post-parturition. The pups were weaned at 6 weeks after which point half of the samples were collected, while the rest of the pups remained on a normal diet, separated into sedentary or voluntary wheel run groups, and collected 12 weeks later. In utero exposure to maternal exercise was associated with higher neuronal nuclear protein, higher soluble APPα and lower soluble APPβ in offspring prefrontal cortex tissue at 6, but not 18 weeks of age. Neuronal nuclear protein is exclusive to mature neurons implying that offspring of mothers who exercised could have more neuron maturation potentially influenced by the higher APPα content at this early developmental stage. The voluntary wheel run offspring groups had a higher mature/pro brain derived neurotrophic factor ratio compared to the sedentary counterparts. The maternal effects were isolated to the juvenile 6-week-old pups, while the differences in the adult offspring were caused by their own exercise status.

One Year of Heavy Resistance Training Modifies Muscle Fiber Characteristics in the Elderly.

Physical function declines with age, accelerating during the 6th decade of life, primarily due to loss in muscle mass and strength. The present study aimed to investigate the effect of one year of heavy resistance training in older adults (62-70 years) on muscle mass and strength. Further, we investigated muscle characteristics after the intervention by obtaining muscle biopsies from the vastus lateralis to compare muscle fiber characteristics between the heavy resistance training (HRT) (n=10) and the sedentary control group (CON) (n=10). We found that one year of resistance training increased isometric muscle strength (p<0.0001, ES: 2.43 (Hedges' g)) and lean body mass (p<0.05, ES: 0.96), whereas cross-sectional area of the vastus lateralis and lean leg mass were unaltered. At year 1, the percentage of type IIX muscle fibers was lower in HRT compared to CON (p<0.05, ES: 0.99), whereas the muscle fiber size did not differ between groups for the major fiber types (I and II). In conclusion, one year of resistance training in elderly improved muscle strength and lean body mass but not cross-sectional area and lean leg mass. This indicates that the increase in muscle strength may be caused by neuromuscular adaptations rather than morphological muscle tissue changes per se.

Effect of climate on emergency department admissions for renal colic: a comparative analysis of sedentary and non-sedentary lifestyles.

To investigate the impact of climate and seasonal variations on emergency department (ED) admissions for renal colic, while specifically comparing the differences between individuals with sedentary and non-sedentary lifestyles. A retrospective, single center study was conducted. Between the years 2017- 2020, medical records of patients admitted to the ED with renal colic, found to harbor ureteric stones on CT scans, were examined. Data on patients' occupational activities was collected through telephone questionnaires. Patients were categorized into two groups: sedentary and active. Precise weather data was obtained from the Israeli Meteorological Service website. The monthly average daily maximum temperatures were calculated. In the final sample of 560 participants, 285 were in the sedentary group, and 275 were in the active group. The study population consisted of 78.1% males and 21.9% females, with consistent gender ratios in both occupational groups. Prevalence of uric acid stones was higher in the sedentary group (p < 0.05). While there was a slight increase in admissions during the summer, seasonal distribution did not significantly differ among occupational groups. The study found no significant differences in admissions across different temperature ranges. Both groups exhibited a pattern of increased referrals during the summer and reduced referrals in the colder winter months. The baseline data revealed notable differences between the sedentary and active groups, particularly in the prevalence of uric acid stones. Climate factors, including temperature and seasonal variations, had limited impact on ED admissions for renal colic in patients with kidney stones, irrespective of their sedentary or active lifestyles. Both groups exhibited similar admission patterns, with a higher rate of admissions during the summer and a lower rate of admissions during the winter.

Comparison of choroidal thickness, superficial and deep retinal vascular indices, and foveal avascular zones: Martial arts athletes vs healthy non-athletes

AimThe study aims to compare choroidal thickness, deep and superficial retinal capillary plexuses, and foveal avascular zone (FAZ) parameters in elite martial arts athletes and a healthy sedentary control group. MethodsThe study included martial arts athletes (32 individuals, 64 eyes) and healthy sedentary persons (43 individuals with healthy sedentary lifestyles, 86 eyes) aged 18–35 years. In this single non-repeated observational and cross-sectional study, choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ measurements were measured using Swept-source optical coherence tomography angiography (SS-OCTA) and compared between groups. ResultsNo statistically significant differences were found (p > 0.05) in age, IOP, AL (axial length), and best-corrected visual acuity (BCVA) parameters between groups. There were no statistically significant differences between the groups in choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ parameters determined by the OCTA method (p > 0.05). ConclusionIn our study, we observed that the retinal and choroidal structures of martial art athletes and healthy sedentary individuals were similar. This observation implies that the putative microvascular effects on the choroid and retina in martial arts, especially those based on the anaerobic energy system, may reflect similar outcomes to those observed in individuals with sedentary lifestyles characterized by healthiness.

The Influence of Aerobic Exercise on Hippocampal Glial Cells and Inflammatory Factor Expression in the Aging Process of Rats

The objective is to analyze the impact of aerobic exercise on the activation of hippocampal glial cells and the expression of inflammatory factors in the aging process of rats. Methods: Thirty male SPF (Specific Pathogen Free) rats at 10 weeks of age were selected and divided into three groups: the sedentary group (A), the aging group (B), and the aging exercise group (C), with 10 rats in each group. The sedentary group (A) was raised for 6 weeks without exercise or aging intervention; the aging group (B) was continuously injected with D-galactose for 6 weeks without exercise intervention; the aging exercise group (C) was continuously injected with D-galactose for 6 weeks while simultaneously implementing exercise intervention, with 60 minutes of unassisted swimming per day, three times a week (swimming pool size 0.5m x 0.8m, water temperature 35±2°C). All groups were harvested at the end of 6 weeks. Compared with the sedentary group, the GFAP immunohistochemical staining in the hippocampal area of the brain was stronger in both the aging group and the aging exercise group, with more GFAP expression, darker positive reaction color, and higher average fluorescence intensity than the sedentary group; compared with the aging group, the aging exercise group had less GFAP expression, lighter positive reaction color, and lower average fluorescence intensity. All differences were significant (P&lt;0.05). In the comparison of GSH levels in the hippocampal tissue of rats, the aging group had the lowest levels, indicating a decrease in the activation level of glial cells in the hippocampus, while the aging exercise group had higher GSH levels than the aging group, proving that exercise intervention in the aging process can effectively improve the activation level of hippocampal glial cells in rats.

Association between inflammatory biomarkers and hypertension among sedentary adults in US: NHANES 2009-2018.

Our study focuses on the relationship between inflammatory biomarkers and hypertension among sedentary adults in the United States, using data from the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2018. We categorized 24,614 participants into two groups based on their daily sedentary time: 9607 individuals in the sedentary group (≥7h) and 15,007 in the non-sedentary group(<7h). We found that the sedentary group had a significantly higher prevalence of hypertension than the non-sedentary group. Using weighted multiple logistic regression and smoothing curves, we assessed the correlation between inflammatory biomarkers and hypertension among the sedentary adults. The odds ratios for hypertension were 1.92 for the monocyte to high-density lipoprotein ratio (MHR), 1.15 for the systemic inflammation response index (SIRI), and 1.19 for the natural logarithm of the systemic immune-inflammation index (lnSII), all showing nonlinear associations. Furthermore, a significant positive correlation was found between sedentary time and inflammatory biomarkers (MHR, SIRI, and lnSII). Our findings suggest that prolonged sedentary behavior in the US significantly increases hypertension risk, likely due to marked increases in inflammation markers.

Association between sedentary behavior, screen time and metabolic syndrome among Chinese children and adolescents

BackgroundThe aim of the study was to investigate the relationship between sedentary behavior, screen time and MetS among Chinese children and adolescents aged 7–17 years. Data was obtained from the China National Nutrition and Health Surveillance of Children and Lactating Mothers in 2016–2017.MethodsData on sedentary time, screen time, and MetS indicators were obtained through physical and health questionnaires, anthropometric measurements, and clinical examinations. MetS was defined according to the Cook’s criteria. Wilcoxon rank sum test and chi-square test were applied for comparisons of measurement data and counting data, respectively. The relationship between sedentary time, screen time, and MetS and its components was analyzed using a multivariate logistic regression model.ResultsThe prevalence of MetS among 7-17-year-old students in 2016–2017 was 5.45%. Compared to those with low sedentary behavior, in high sedentary behavior groups, the prevalence of abdominal obesity, high TG, low HDL-C, and MetS was high in boys, and the prevalence of abdominal obesity, high TG, hyperglycemia, and MetS was high in girls. Moreover, for those who reported ≥ 3 h/day of screen time, the prevalence of abdominal obesity, low HDL-C, and MetS was higher in boys, and the prevalence of abdominal obesity and MetS was higher in girls. After adjusting for confounding variables, the risks of abdominal obesity, high TG, low HDL-C, and MetS were higher in high-level sedentary time group, and the risks of abdominal obesity and MetS were 1.15 and 1.14 times higher for those who spent ≥ 3 h/day on screen time, respectively.ConclusionsThis study shows that high levels of sedentary time and screen time were associated with an increased likelihood of MetS among Chinese children and adolescents aged 7–17 years. Reducing sedentary behavior and screen time may contribute to the prevention of metabolic diseases.

High-intensity interval training and medium-intensity continuous training may affect cognitive function through regulation of intestinal microbial composition and its metabolite LPS by the gut-brain axis

AimsThe gut-brain axis is the communication mechanism between the gut and the central nervous system, and the intestinal flora and lipopolysaccharide (LPS) play a crucial role in this mechanism. Exercise regulates the gut microbiota composition and metabolite production (i.e., LPS). We aimed to investigate the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cognitive function in C57BL/6 J mice through gut-brain axis regulation of gut microbiota composition and LPS displacement. Main methodsC57BL/6 J male mice were randomly divided into sedentary, HIIT, and MICT groups. After 12 weeks of exercise intervention, the cognitive function of the brain and mRNA levels of related inflammatory factors were measured. RNA sequencing, Golgi staining, intestinal microbial 16 s rDNA sequencing, and ELISA were performed. Key findingsHIIT and MICT affect brain cognitive function by regulating the gut microbiota composition and its metabolite, LPS, through the gut microbiota-gut-brain axis. HIIT is suspected to have a risk: it can induce “intestinal leakage” by regulating intestinal permeability-related microbiota, resulting in excessive LPS in the blood and brain and activating M1 microglia in the brain, leading to reduced dendritic spine density and affecting cognitive function. SignificanceThis study revealed a potential link between changes in the gut microbiota and cognitive function. It highlighted the possible risk of HIIT in reducing dendritic spine density and affecting cognitive function.

Sedentary behaviour may cause differences in physical outcomes and activities of daily living in older cardiovascular disease patients participating in phase I cardiac rehabilitation

This study aimed to investigate the rate of sedentary behaviour and differences in physical outcomes and activities of daily living (ADL) based on sedentary behaviour time of hospitalized older cardiovascular disease patients undergoing phase I cardiac rehabilitation. Older cardiovascular disease patients were enrolled from October 2020 to September 2023 and were divided into the high sedentary behaviour group (≥ 480 min/day) and low sedentary behaviour group (< 480 min/day). Patients’ clinical characteristics, usual gait speed, and Five Times Sit to Stand Test time were compared as indices of physical outcomes. Motor, cognitive, and total Functional Independence Measure (FIM) scores were used as indices of ADL and compared between groups using analysis of covariance. Final analysis included 402 patients (mean age: 76.7 years, female: 35.3%). The high sedentary behaviour group included 48.5% of the study patients. After adjustment for baseline characteristics, gait speed (0.80 ± 0.27 vs. 0.96 ± 0.23 m/s, p < 0.001) was lower and FTSST time (11.31 ± 4.19 vs. 9.39 ± 3.11 s, p < 0.001) was higher in the high sedentary behaviour group versus low sedentary behaviour group. Motor (85.82 ± 8.82 vs. 88.09 ± 5.04 points, p < 0.001), cognitive (33.32 ± 2.93 vs. 34.04 ± 2.24 points, p < 0.001), and total FIM scores (119.13 ± 10.66 vs. 122.02 ± 6.30 points, p < 0.001) were significantly lower in the high sedentary behaviour group versus low sedentary behaviour group after adjustment. In older cardiovascular disease patients in phase I cardiac rehabilitation, sedentary behaviour time might influence physical outcomes and ADL at discharge. It is thus important to consider the amount of sedentary behaviour time spent by these patients during daily life while hospitalized.

Sociodemographic profile, index of functional autonomy and physical activity level of elderly women

To analyze the sociodemographic profile, functional autonomy index and level of physical activity of elderly women participating in an exercise program. 372 elderly women participating in the MASTERFITTS program and completed questionnaires regarding medical history and the adapted Baecke questionnaire to assess the level of physical activity in elderly. Tests from the GDLAM protocol were performed to evaluate functional autonomy. 51.61% were physically active ( = 2.68±0.49; ∆% = 1.09), and the majority achieved a good classification in the tests and overall functional autonomy index. A significant difference was found in the W10m test (p= 0.041; ∆% = -0.89), RSP (p= 0.024; ∆% = -1.90), and RVDP (p= 0.032; ∆% = -1.20) between the active and sedentary groups. An increase in the level of physical activity will also lead to a decrease in the completion times of the functional autonomy assessment tests, contributing to improved health.

Epidemiological analysis of cardiac risk factors in elderly people

This study analyzed cardiac risk factors found in older adults, highlighting the increased incidence of cardiovascular diseases with advancing age. A total of 372 elderly individuals were evaluated at Basic Health Units, and divided into sedentary and active groups. Research emphasized the importance of physical activity in reducing cardiovascular risk, using the Framingham Score to identify high cardiovascular risk and to guide interventions. The sociodemographic analysis included age group, ethnicity, marital status, education, income, and family history of diseases. Bayesian inferences were conducted to assess the number of simultaneous changes in variables and calculate the proportion of individuals with potential cardiac risk. The final conclusion of Bayesian inferences indicates that approximately 29.0% of individuals in the sample may bear potential cardiovascular risk due to two or more alterations in the evaluated variables.

Free essential amino acid feeding improves endurance during resistance training via DRP1-dependent mitochondrial remodelling.

Loss of muscle strength and endurance with aging or in various conditions negatively affects quality of life. Resistance exercise training (RET) is the most powerful means to improve muscle mass and strength, but it does not generally lead to improvements in endurance capacity. Free essential amino acids (EAAs) act as precursors and stimuli for synthesis of both mitochondrial and myofibrillar proteins that could potentially confer endurance and strength gains. Thus, we hypothesized that daily consumption of a dietary supplement of nine free EAAs with RET improves endurance in addition to the strength gains by RET. Male C57BL6J mice (9weeks old) were assigned to control (CON), EAA, RET (ladder climbing, 3 times a week), or combined treatment of EAA and RET (EAA+RET) groups. Physical functions focusing on strength or endurance were assessed before and after the interventions. Several analyses were performed to gain better insight into the mechanisms by which muscle function was improved. We determined cumulative rates of myofibrillar and mitochondrial protein synthesis using 2H2O labelling and mass spectrometry; assessed ex vivo contractile properties and in vitro mitochondrial function, evaluated neuromuscular junction (NMJ) stability, and assessed implicated molecular singling pathways. Furthermore, whole-body and muscle insulin sensitivity along with glucose metabolism, were evaluated using a hyperinsulinaemic-euglycaemic clamp. EAA+RET increased muscle mass (10%, P<0.05) and strength (6%, P<0.05) more than RET alone, due to an enhanced rate of integrated muscle protein synthesis (19%, P<0.05) with concomitant activation of Akt1/mTORC1 signalling. Muscle quality (muscle strength normalized to mass) was improved by RET (i.e., RET and EAA+RET) compared with sedentary groups (10%, P<0.05), which was associated with increased AchR cluster size and MuSK activation (P<0.05). EAA+RET also increased endurance capacity more than RET alone (26%, P<0.05) by increasing both mitochondrial protein synthesis (53%, P<0.05) and DRP1 activation (P<0.05). Maximal respiratory capacity increased (P<0.05) through activation of the mTORC1-DRP1 signalling axis. These favourable effects were accompanied by an improvement in basal glucose metabolism (i.e., blood glucose concentrations and endogenous glucose production vs. CON, P<0.05). Combined treatment with balanced free EAAs and RET may effectively promote endurance capacity as well as muscle strength through increased muscle protein synthesis, improved NMJ stability, and enhanced mitochondrial dynamics via mTORC1-DRP1 axis activation, ultimately leading to improved basal glucose metabolism.

Short-term aerobic exercise prevents development of glucocorticoid myopathic features in aged skeletal muscle in a sex-dependent manner.

Older adults are vulnerable to glucocorticoid-induced muscle atrophy and weakness, with sex potentially influencing their susceptibility to those effects. Aerobic exercise can reduce glucocorticoid-induced muscle atrophy in young rodents. However, it is unknown whether aerobic exercise can prevent glucocorticoid myopathy in aged muscle. The objectives of this study were to define the extent to which sex influences the development of glucocorticoid myopathy in aged muscle, and to determine the extent to which aerobic exercise training protects against myopathy development. Twenty-four-month-old female (n = 30) and male (n = 33) mice were randomized to either sedentary or aerobic exercise groups. Within their respective groups, mice were randomized to either daily treatment with dexamethasone (DEX) or saline. Upon completing treatments, the contractile properties of the triceps surae complex were assessed in situ. DEX marginally lowered muscle mass and soluble protein content in both sexes, which was attenuated by aerobic exercise only in females. DEX increased sub-tetanic force and rate of force development only in females, which was not influenced by aerobic exercise. Muscle fatigue was higher in both sexes following DEX, but aerobic exercise prevented fatigue induction only in females. The sex-specific differences to muscle function in response to DEX treatment coincided with sex-specific changes to the content of proteins related to calcium handling, mitochondrial quality control, reactive oxygen species production, and glucocorticoid receptor in muscle. These findings define several important sexually dimorphic changes to aged skeletal muscle physiology in response to glucocorticoid treatment and define the capacity of short-term aerobic exercise to protect against those changes. KEY POINTS: There are sexually dimorphic effects of glucocorticoids on aged skeletal muscle physiology. Glucocorticoid-induced changes to aged muscle contractile properties coincide with sex-specific differences in the content of calcium handling proteins. Aerobic exercise prevents glucocorticoid-induced fatigue only in aged females and coincides with differences in the content of mitochondrial quality control proteins and glucocorticoid receptors.

Estimating the Total and Regional Body Fat of Physically Active Men Is Not Appropriate for Sedentary Men

Objectives. The reliability of predictive body fat equations remains unclear due to their inappropriate use across different subject cohorts and conditions. The objective of this study was to validate and cross-validate equations to predict total and regional body fat in young physically active males. Material and methods. Three hundred and five young male participants were divided into the following groups: active validation (n=165), active cross-validation (n=70), or sedentary cross-validation ones (n=70). The study used a stratified random sampling based on weekly physical activity level. The total and regional body fat mass were measured using dual-energy X-ray absorptiometry (DEXA) after an overnight fast. Simultaneous measurements of height, body mass, skinfold thickness, body mass index, and body circumferences were taken. The total and regional body fat predictive equations were generated using multiple linear stepwise regression models. The coefficient of determination (R²) and standard error of estimation (SEE) were calculated to examine the accuracy of the predictive equations. Furthermore, cross-validation groups were analysed. Results. The percentage of total body fat, trunk fat, legs fat, arms fat, and body mass index of active cross-validation were found to be significantly lower than in the sedentary cross-validation groups. The total body fat percentage was highly associated with abdominal skinfold thickness (R=0.68-0.74, P&lt;0.001), body mass index (R=0.55, P&lt;0.001), and suprailiac skinfold thickness (R=0.67-0.71, P&lt;0.001) in the active validation group. The predictive total and regional body fat equations of physically active men showed adjusted R² values ranging from 0.35 to 0.66, with standard error of estimation values between 2.74 to 4.35%. The standard error of estimation for the predictive percentage of total and regional body fat in the active cross-validation group was lower than in the sedentary cross-validation group. Conclusions. The findings demonstrate that new predictive total and regional body fat equations can be used to accurately estimate body fat in healthy young active males under fast conditions.

Unconsciously triggered cognitive conflict influences perceptual choice in active and sedentary individuals.

People who regularly exercise and receive training perform better when actioning unconscious cognitive tasks. The information flow triggered by a single unconscious visual stimulus has been extensively investigated, but it remains unclear whether multiple unconscious visual stimuli interact. This study aimed to explore the relationship between three simultaneous subliminal arrow stimuli (pointing in same or different directions), focusing on how they interact with each other and the subsequent priming effect on the target arrow in active and sedentary groups. We used a priming paradigm combining flanker task to test the hypothesis. A total of 42 participants were recruited. Of these, 22 constituted the active group and 20 constituted the sedentary group. Behavioral data results revealed that the main effects of group and prime-target compatibility were significant. In the neurophysiological data, prime-target compatibility significantly influenced the latency of PP1. The amplitude of TP1 and TN2 mainly influenced the prime-flanker congruency. The prime-flanker congruency and groups interacted when the prime-target showed sufficient compatibility. The prime-flanker congruency, and the prime-target compatibility considerably influenced the TP3 amplitude in the anterior central frontal region (CZ electrode point). Event-related potentials revealed the interactions between conscious processing and subliminal conflict in the early stages of perceptual and attention processing (target-related P1 potential component). These results suggest that exercise is helpful for coping with unconscious cognitive conflict.

Effects of endurance training under calorie restriction on energy substrate metabolism in mouse skeletal muscle and liver

We investigated whether calorie restriction (CR) enhances metabolic adaptations to endurance training (ET). Ten-week-old male Institute of Cancer Research (ICR) mice were fed ad libitum or subjected to 30% CR. The mice were subdivided into sedentary and ET groups. The ET group performed treadmill running (20–25 m/min, 30 min, 5 days/week) for 5 weeks. We found that CR decreased glycolytic enzyme activity and monocarboxylate transporter (MCT) 4 protein content, while enhancing glucose transporter 4 protein content in the plantaris and soleus muscles. Although ET and CR individually increased citrate synthase activity in the plantaris muscle, the ET-induced increase in respiratory chain complex I protein content was counteracted by CR. In the soleus muscle, mitochondrial enzyme activity and protein levels were increased by ET, but decreased by CR. It has been suggested that CR partially interferes with skeletal muscle adaptation to ET.