Effect of acute concurrent exercise training and the mediating role of lactate on executive function: An ERP study.

Both acute aerobic (AE) and resistance exercise (RE) have been acknowledged to be effective methods in enhancing executive function and brain-related P3 amplitudes. Nevertheless, the effect of acute concurrent exercise training (CET), combining both AE and RE, on executive function remains subject to speculation. Moreover, investigation of the mechanisms that underlie improvements in executive function would facilitate scientific understanding. Notably, lactate has emerged as a candidate among several potential mechanisms. Therefore, the main aim of the present study was to investigate the effect of acute CET on the cognitive flexibility dimension of executive function using behavioural and neuro-electric measures. A secondary aim was to determine the mediating effect of blood lactate in the acute exercise-executive function relationship. Seventy-eight young adults (38 women, 40 men; 22.8 ± 1.8 years) were randomly assigned to one of the following groups: CET, AE, or reading control (RC). Cognitive flexibility was evaluated using the Task-Switching Test and its derived electroencephalography (EEG) was assessed immediately prior to and following each treatment. Fingertip lactate assays were taken prior to, at the midpoint, and after each treatment. Both acute CET and AE shortened response time regardless of test conditions when compared to the RC group. Greater P3 amplitude was observed following CET in the heterogeneous condition and under AE in the switch condition. A significant mediation of blood lactate for response time emerged in both the CET and AE groups for the heterogeneous and switch conditions. The blood lactate mediation was not reflected in P3 amplitude. The present findings suggest that acute CET leads to positive behavioural and neuro-electric alterations of cognitive flexibility, and its effect is similar to AE. Additionally, blood lactate serves as a mediator of the effects of acute exercise on executive function from a behavioural, but not neuro-electric standpoint.

Defecation enhances cerebral perfusion and delays fatigue in elite triathletes.

BACKGROUND: Rectal distension increases regulatory burden to autonomic nervous system in the brain. PURPOSE: To determine the effect of rectal defecation on endurance performance and blood supply to the prefrontal brain and sub-navel regions of elite triathletes. METHODS: Thirteen elite triathletes completed a cycling time trial (80% VO2max) under defecated and non-defecated conditions, using a counterbalanced crossover design. Oxygenation and blood distribution in prefrontal brain and sub-navel regions were monitored by near-infrared spectroscopy (NIRS) during cycling. RESULTS: Defecation moderately decreased systolic blood pressure (-4 mmHg, p < 0.05, d = 0.71), suggesting an alleviation of autonomic nervous activity. During the exercise trials, fatigue (cycling time to exhaustion) occurred when cerebral oxygenation decreased to ~ 5 % below baseline regardless of treatment conditions, suggesting a critical deoxygenation point for sustaining voluntary exertions. Cerebral blood (estimated by total hemoglobin) increased progressively throughout the entire exercise period. Defecation decreased sub-navel oxygenation levels below the non-defecated level, suggesting an increased sub-navel oxygen consumption. Exercise also decreased sub-navel blood distribution, with minimal difference between non-defecated and defecated conditions. Defecation improved blood pooling in the prefrontal brain during exercise (p < 0.05) and enhanced cycling performance in triathletes (Non-defecated: 1624 ± 138 s vs. defecated: 1902 ± 163 s, d = 0.51, p < 0.05). CONCLUSION: Our results suggest that improved exercise performance after defecation is associated with greater blood availability to compensate deoxygenation in the prefrontal brain region during exercise. Further investigation is needed to examine the role of increasing sub-navel oxygen consumption in the performance improvement after defecation.

Changes in Arterial Stiffness in Response to Various Types of Exercise Modalities: A Narrative Review on Physiological and Endothelial Senescence Perspectives.

Arterial stiffness is a reliable independent predictor of cardiovascular events. Exercise training might enhance arterial compliance through improved metabolic health status. Different modes of exercise may have different effects on arterial stiffness. However, the interactions among different modes of exercise on endothelial senescence, the development of arterial vascular stiffness, and the associated molecular mechanisms are not completely understood. In this narrative review, we evaluate the current evidence focusing on the effects of various exercise modes on arterial stiffness and vascular health, and the known underlying physiological mechanisms are discussed as well. Here, we discuss the most recent evidence of aerobic exercise, high-intensity interval training (HIIT), and resistance exercise (RE) on arterial stiffness and endothelial senescence in physiological and cellular studies. Indeed, aerobic, HIIT, and progression RE-induced arterial compliance may reduce arterial stiffness by effectively promoting nitric oxide (NO) bioavailability and reducing endothelial senescence. However, the transient increase in inflammation and sympathetic activation may contribute to the temporary elevation in arterial stiffness following whole-body high-intensity acute resistance exercise.

Effects of the Short-Foot Exercise on Foot Alignment and Muscle Hypertrophy in Flatfoot Individuals: A Meta-Analysis.

This study aimed to conduct a meta-analysis of randomized controlled trials to examine the effects of the short-foot exercise (SFE) compared to foot orthosis or other types of interventions. Eligibility criteria involved participants with flatfoot engaging in the SFE compared to other forms of intervention or control groups without specific intervention. Relevant studies published before the end of June 2022 were identified from databases. A meta-analysis was performed by calculating the mean differences (MD) and standard MD (SMD) using the random effects model. Six trials with 201 patients (out of 609 records) that met selection criteria were reviewed. Five of the six trials implemented distinct interventions in the control group such as shoe insoles and muscle strengthening exercises, while in the remaining trial, controls received no intervention. The SFE group significantly reduced the navicular drop test (NDT) values (MD: -0.23; 95% confidence interval: -0.45 to -0.02; p = 0.04) and the foot posture index (FPI-6) score (MD: -0.67; 95% confidence interval: -0.98 to -0.36; p < 0.0001) when compared to the control group. The muscle hypertrophy did not differ significantly between the groups. The SFE may contribute more benefits than other intervention as it affects flatfoot individuals' foot alignment. Hence, the SFE is recommended as a beneficial dynamic support when facing flatfoot problems.

Stochastic currents and efficiency in an autonomous heat engine.

We experimentally demonstrate that a Brownian gyrator of a colloidal particle confined in a two-dimensional harmonic potential with different effective temperatures on orthogonal axes can work as an autonomous heat engine capable of extracting work from the heat bath, generated by an optical feedback trap. The results confirm the theoretically predicted thermodynamic currents and validate the attainability of Carnot efficiency as well as the trade-off relation between power and efficiency. We further show that current fluctuations and the entropy production rate are time independent in the steady state and their product near the Carnot efficiency is close to the lower bound of the thermodynamic uncertainty relation.

Do E2 and P4 contribute to the explained variance in core temperature response for trained women during exertional heat stress when metabolic rates are very high?

PURPOSE: Women remain underrepresented in the exercise thermoregulation literature despite their participation in leisure-time and occupational physical activity in heat-stressful environments continuing to increase. Here, we determined the relative contribution of the primary ovarian hormones (estrogen [E2] and progesterone [P4]) alongside other morphological (e.g., body mass), physiological (e.g., sweat rates), functional (e.g., aerobic fitness) and environmental (e.g., vapor pressure) factors in explaining the individual variation in core temperature responses for trained women working at very high metabolic rates, specifically peak core temperature (Tpeak) and work output (mean power output). METHODS: Thirty-six trained women (32 ± 9 year, 53 ± 9 ml·kg-1·min-1), distinguished by intra-participant (early follicular and mid-luteal phases) or inter-participant (ovulatory vs. anovulatory vs. oral contraceptive pill user) differences in their endogenous E2 and P4 concentrations, completed a self-paced 30-min cycling work trial in warm-dry (2.2 ± 0.2 kPa, 34.1 ± 0.2 °C, 41.4 ± 3.4% RH) and/or warm-humid (3.4 ± 0.1 kPa, 30.2 ± 1.2 °C, 79.8 ± 3.7% RH) conditions that yielded 115 separate trials. Stepwise linear regression was used to explain the variance of the dependent variables. RESULTS: Models were able to account for 60% of the variance in Tpeak ([Formula: see text]2: 41% core temperature at the start of work trial, [Formula: see text]2: 15% power output, [Formula: see text]2: 4% [E2]) and 44% of the variance in mean power output ([Formula: see text]2: 35% peak aerobic power, [Formula: see text]2: 9% perceived exertion). CONCLUSION: E2 contributes a small amount toward the core temperature response in trained women, whereby starting core temperature and peak aerobic power explain the greatest variance in Tpeak and work output, respectively.

Heterogeneous nanoscopic lipid diffusion in the live cell membrane and its dependency on cholesterol.

Cholesterol plays a unique role in the regulation of membrane organization and dynamics by modulating the membrane phase transition at the nanoscale. Unfortunately, due to their small sizes and dynamic nature, the effects of cholesterol-mediated membrane nanodomains on membrane dynamics remain elusive. Here, using ultrahigh-speed single-molecule tracking with advanced optical microscope techniques, we investigate the diffusive motion of single phospholipids in the live cell plasma membrane at the nanoscale and its dependency on the cholesterol concentration. We find that both saturated and unsaturated phospholipids undergo anomalous subdiffusion on the length scale of 10-100 nm. The diffusion characteristics exhibit considerable variations in space and in time, indicating that the nanoscopic lipid diffusion is highly heterogeneous. Importantly, through the statistical analysis, apparent dual-mobility subdiffusion is observed from the mixed diffusion behaviors. The measured subdiffusion agrees well with the hop diffusion model that represents a diffuser moving in a compartmentalized membrane created by the cytoskeleton meshwork. Cholesterol depletion diminishes the lipid mobility with an apparently smaller compartment size and a stronger confinement strength. Similar results are measured with temperature reduction, suggesting that the more heterogeneous and restricted diffusion is connected to the nanoscopic membrane phase transition. Our conclusion supports the model that cholesterol depletion induces the formation of gel-phase, solid-like membrane nanodomains. These nanodomains undergo restricted diffusion and act as diffusion obstacles to the membrane molecules that are excluded from the nanodomains. This work provides the experimental evidence that the nanoscopic lipid diffusion in the cell plasma membrane is heterogeneous and sensitive to the cholesterol concentration and temperature, shedding new light on the regulation mechanisms of nanoscopic membrane dynamics.

Effects of Acute Interval Exercise on Arterial Stiffness and Cardiovascular Autonomic Regulatory Responses: A Narrative Review of Potential Impacts of Aging.

The physiological changes associated with aging deleteriously impact cardiovascular function and regulation and therefore increase the risk of developing cardiovascular disease. There is substantial evidence that changes in the autonomic nervous system and arterial stiffness play an important role in the development of cardiovascular disease during the aging process. Exercise is known to be effective in improving autonomic regulation and arterial vascular compliance, but differences in the type and intensity of exercise can have varying degrees of impact on vascular regulatory responses and autonomic function. There is still little evidence on whether there are differences in the response of exercise interventions to cardiovascular modulatory effects across the lifespan. In addition, acute interval exercise challenges can improve autonomic modulation, although the results of interval exercise on autonomic physiological parameters vary. Therefore, this narrative review focuses on evaluating the effects of acute interval exercise on blood pressure regulation and autonomic responses and also incorporates studies investigating different age groups to evaluate the effects of acute interval exercise on the autonomic nervous system. Herein we also summarize existing literature examining the acute cardiovascular responses to varied modes of interval exercise, as well as to further compare the benefits of interval exercise with other types of exercise on autonomic regulation and arterial stiffness. After reviewing the existing literature, it has been shown that with advancing age, changes in the autonomic nervous activity of interval exercise result in significant impacts on the cardiovascular system. We document that with advancing age, changes in the autonomic nerves lead to aging of the nervous system, thereby affecting the regulation of blood pressure. According to the limited literature, interval exercise is more effective in attenuating arterial stiffness than continuous exercise, but the difference in exercise benefits may depend on the training mode, intensity, duration of exercise, and the age of participants. Therefore, the benefits of interval exercise on autonomic and arterial stiffness improvement still warrant investigation, particularly the impact of age, in future research.

Monitoring the Changing Patterns in Perceived Learning Effort, Stress, and Sleep Quality during the Sports Training Period in Elite Collegiate Triathletes: A Preliminary Research.

Background: Few studies have examined the mental profiles and academic status of collegiate triathletes during training/competitive periods. We evaluated the changes in sleep quality, physical fatigue, emotional state, and academic stress among collegiate triathletes across training periods. Methods: Thirteen collegiate triathletes (19−26 years old) were recruited in this study. Mood state, sleep quality, degree of daytime sleepiness, subjective fatigue, and academic learning states were measured during the following five training periods: before national competitions for 3 months (3M-Pre Comp), 2 months (2M-Pre Comp), 1 month (1M-Pre Comp), 2 weeks (2wk-Pre Comp), and national competition (Comp) according to their academic/training schedule. Results: The academic stress index in 1M-Pre Comp (Final exam) was significantly higher than that in 3M-Pre Comp in these triathletes. No markedly significant differences were observed in overall mood state, sleep quality, individual degree of sleepiness, and fatigue among these five periods. However, the profiles mood state scale (POMS)-fatigue and -anger were lower in 2wk-Pre Comp than that in 1M-Pre com. The POMS-tension score in Comp was significantly higher than that in 3M-Pre Comp and 2M-Pre Comp. POMS-depression in Comp was lower than that in 1M-Pre Comp. Conclusion: We found that training volume was highest one month before a competition, and the academic stress is greatest during their final term exam period (1M-Pre Comp). After comprehensive assessment through analyzing POMS, PSQI, ESS, and personal fatigue (CIS), we found that the collegiate triathletes exhibited healthy emotional and sleep states (PSQI score < 5) across each training period, and our results suggest that these elite collegiate triathletes had proficient self-discipline, time management, and mental adjustment skills.

A Sports Nutrition Perspective on the Impacts of Hypoxic High-Intensity Interval Training (HIIT) on Appetite Regulatory Mechanisms: A Narrative Review of the Current Evidence.

High-intensity interval training (HIIT) and low-oxygen exposure may inhibit the secretion of appetite-stimulating hormones, suppress appetite, and inhibit dietary intake. Physiological changes affecting appetite are frequent and include appetite hormone (ghrelin, leptin, PYY, and GLP-1) effects and the subjective loss of appetite, resulting in nutritional deficiencies. This paper is a narrative review of the literature to verify the HIIT effect on appetite regulation mechanisms and discusses the possible relationship between appetite effects and the need for high-intensity exercise training in a hypoxic environment. We searched MEDLINE/PubMed and the Web of Science databases, as well as English articles (gray literature by Google Scholar for English articles) through Google Scholar, and the searched studies primarily focused on the acute effects of exercise and hypoxic environmental factors on appetite, related hormones, and energy intake. In a general normoxic environment, regular exercise habits may have accustomed the athlete to intense training and, therefore, no changes occurred in their subjective appetite, but there is a significant effect on the appetite hormones. The higher the exercise intensity and the longer the duration, the more likely exercise is to cause exercise-induced appetite loss and changes in appetite hormones. It has not been clear whether performing HIIT in a hypoxic environment may interfere with the exerciser's diet or the nutritional supplement intake as it suppresses appetite, which, in turn, affects and interferes with the recovery efficiency after exercise. Although appetite-regulatory hormones, the subjective appetite, and energy intake may be affected by exercise, such as hypoxia or hypoxic exercise, we believe that energy intake should be the main observable indicator in future studies on environmental and exercise interventions.

Amyloid-ß40 E22K fibril in familial Alzheimer's disease is more thermostable and susceptible to seeding.

Alzheimer's disease (AD) is the most prevalent and devastating neurodegenerative disease occurred in the elderly. One of the pathogenic hallmarks is senile plaques composed of amyloid-ß (Aß) fibrils. Single mutations resided in Aß were found in familial AD (FAD) patients that have early onset of the disease. The molecular details and properties of each FAD Aß variants are still elusive. Here, we employed collective spectroscopic techniques to examine the properties of various Aß40 fibrils. We generated fibrils of wild type (WT) and three FAD mutants on residue E22 including E22G, E22K, and E22Q. We monitored fibril formation by thioflavin T (ThT) assay, examined secondary structure by Fourier transform infrared and far-UV circular dichroism spectroscopy, imaged fibril morphology by transmission electron microscopy, and evaluated ThT-binding kinetics. In the thermal experiments, we found E22K fibrils resisted to high temperature and retained significant ß-sheet content than the others. E22K fibril seeds after high-temperature treatment still possess the seeding property, whereas WT fibril seeds are disturbed after the treatment. Therefore, in this study we demonstrated the mutation at E22K increases the thermal stability and seeding function of amyloid fibrils.

"The Competitive Season and Off-Season": Preliminary Research concerning the Sport-Specific Performance, Stress, and Sleep in Elite Male Adolescent Basketball Athletes.

BACKGROUND: Through scholastic sports programs, adolescent athletes compete to represent their communities. However, few studies investigate the changes in physiological and mental profiles during varied sport periodization among this population. Therefore, the purpose of this study was to compare the changes in sports performance and stress-related biomarkers between the competitive season (CS) and off-season (OS) in elite adolescent basketball players. METHOD: Nine elite Division I male basketball players (age: 15-18 years. old) participated in this study. Basketball-specific performance, salivary dehydroepiandrosterone sulfate (DHEA-S)/cortisol levels, mood state, and sleep quality were all accessed during the CS and OS periods. RESULTS: The training load during OS was 26.0% lower than CS (p = 0.001). Muscle mass, aerobic capacity, 10 m sprint, and Abalakov jump (AJ) power during OS were greater than that during CS (+2.2-9.8%, p < 0.05), but planned agility was greater during CS (p = 0.003). The salivary DHEA-S/cortisol was greater during CS than during OS (p = 0.039). The overall mood state and sleep quality did not differ between periods, but the POMS-tension was higher during CS (p = 0.005). CONCLUSION: The present study demonstrates that muscle mass, aerobic capacity, peak AJ power, and 10 m sprint performance, but not planned agility, were greater during OS compared to CS among elite adolescent basketball players. Furthermore, the stress-related responses reflected by the D/C ratio and mood tension were relatively lower during the OS in these athletes. Thus, this study suggests that coaches and sport science professionals should closely monitor athletes' training states across varied training/competition periods to better react to modifying training or recovery plans.

Measurement error of self-paced exercise performance in athletic women is not affected by ovulatory status or ambient environment.

Measurement error(s) of exercise tests for women are severely lacking in the literature. The purpose of this investigation was to 1) determine whether ovulatory status or ambient environment were moderating variables when completing a 30-min self-paced work trial and 2) provide test-retest norms specific to athletic women. A retrospective analysis of three heat stress studies was completed using 33 female participants (31 ± 9 yr, 54 ± 10 mL·min-1·kg-1) that yielded 130 separate trials. Participants were classified as ovulatory (n = 19), anovulatory (n = 4), and oral contraceptive pill users (n = 10). Participants completed trials ∼2 wk apart in their (quasi-) early follicular and midluteal phases in two of moderate (1.3 ± 0.1 kPa, 20.5 ± 0.5°C, 18 trials), warm-dry (2.2 ± 0.2 kPa, 34.1 ± 0.2°C, 46 trials), or warm-humid (3.4 ± 0.1 kPa, 30.2 ± 1.1°C, 66 trials) environments. We quantified reliability using limits of agreement, intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV). Test-retest reliability was high, clinically valid (ICC = 0.90, P < 0.01), and acceptable with a mean CV of 4.7%, SEM of 3.8 kJ (2.1 W), and reliable bias of -2.1 kJ (-1.2 W). The various ovulatory status and contrasting ambient conditions had no appreciable effect on reliability. These results indicate that athletic women can perform 30-min self-paced work trials ∼2 wk apart with an acceptable and low variability irrespective of their hormonal status or heat-stressful environments.NEW & NOTEWORTHY This study highlights that aerobically trained women perform 30-min self-paced work trials ∼2 wk apart with acceptably low variability and their hormonal/ovulatory status and the introduction of greater ambient heat and humidity do not moderate this measurement error.

Perturbations of Adjuvant Chemotherapy on Cardiovascular Responses and Exercise Tolerance in Patients with Early-Stage Breast Cancer.

BACKGROUND: Adjuvant chemotherapies are commonly used for treating early-stage breast cancer. However, whether chemotherapeutic regimens affect exercise tolerance and cardiovascular responses remains unclear. Therefore, we investigated the effects of receiving CAF and AC-T on exercise tolerance and cardiovascular responses in patients with early-stage breast cancer. METHODS: Thirty-four patients with breast cancer (age: 44 ± 1 years; stage I-II) received either CAF (n = 15) or AC-T (n = 19), depending on clinical decisions. Their step-exercise tolerance and cardiovascular responses were assessed before and after chemotherapy. RESULTS: After chemotherapy, there were no differences in baseline measurements between patients receiving CAF or AC-T. The increases in resting heart rate (RHR) of those receiving AC-T was significantly greater than that of those receiving CAF. CAF and AC-T did not result in increased pulse wave velocity (PWV), yet the subendocardial viability ratio (SEVR) in patients receiving AC-T was significantly lower than the baseline. Greater change in post-exercise heart rate recovery (recovery HR) after chemotherapy was observed in those who had received AC-T; the Recovery HR in AC-T patients was significantly higher during post-exercise period than that in CAF patients. CONCLUSIONS: AC-T chemotherapy increases RHR and impairs exercise tolerance after chemotherapy more than CAF. Moreover, AC-T also lowers myocardial perfusion more than CAF after chemotherapy.

Effects of Protein-Rich Nutritional Composition Supplementation on Sarcopenia Indices and Physical Activity during Resistance Exercise Training in Older Women with Knee Osteoarthritis.

Older adults with knee osteoarthritis (KOA) are at high risk of sarcopenia. Protein-rich nutritional composition supplementation (PS) combined with resistance exercise training (RET) improves muscle gains and facilitates physical activity in older adults. However, whether PS augments the effects of RET on muscle mass and PA in patients with KOA remains unclear. Therefore, this study identified the effects of PS on sarcopenic indices and PA in older women with KOA subjected to an RET program. Eligible older women aged 60-85 years and diagnosed as having KOA were randomly assigned to either the experimental group (EG) or the control group (CG). Both groups performed RET twice a week for 12 weeks. The EG received additional PS during this period. Outcome measures included appendicular lean mass index, walking speed, physical activity, and scores on the Western Ontario and McMaster Universities Osteoarthritis Index-WOMAC). All measures were tested at baseline and after intervention. With participant characteristics and baseline scores as covariates, analysis of variance was performed to identify between-group differences in changes in all outcome measures after intervention. Statistical significance was defined as p < 0.05. Compared with the CG, the EG achieved greater changes in appendicular lean mass index (adjusted mean difference (aMD) = 0.19 kg/m2, p < 0.01), physical activity (aMD = 30.0 MET-hour/week, p < 0.001), walking speed (aMD = 0.09 m/s, p < 0.05), and WOMAC global function (aMD = -8.21, p < 0.001) after intervention. In conclusion, PS exerted augmentative effects on sarcopenic indices, physical activity, and perceived global WOMAC score in older women with KOA through 12 weeks of RET.

Amphetamine-Decreased Progesterone and Estradiol Release in Rat Granulosa Cells: The Regulatory Role of cAMP- and Ca2+-Mediated Signaling Pathways.

The purpose of this study is to evaluate the amphetamine effects on progesterone and estradiol production in rat granulosa cells and the underlying cellular regulatory mechanisms. Freshly dispersed rat granulosa cells were cultured with various test drugs in the presence of amphetamine, and the estradiol/progesterone production and the cytosolic cAMP level were measured. Additionally, the cytosolic-free Ca2+ concentrations ([Ca2+]i) were measured to examine the role of Ca2+ influx in the presence of amphetamine. Amphetamine in vitro inhibited both basal and porcine follicle-stimulating hormone-stimulated estradiol/progesterone release, and amphetamine significantly decreased steroidogenic enzyme activities. Adding 8-Bromo-cAMP did not recover the inhibitory effects of amphetamine on progesterone and estradiol release. H89 significantly decreased progesterone and estradiol basal release but failed to enhance a further amphetamine inhibitory effect. Amphetamine was capable of further suppressing the release of estradiol release under the presence of nifedipine. Pretreatment with the amphetamine for 2 h decreased the basal [Ca2+]i and prostaglandin F2α-stimulated increase of [Ca2+]i. Amphetamine inhibits progesterone and estradiol secretion in rat granulosa cells through a mechanism involving decreased PKA-downstream steroidogenic enzyme activity and L-type Ca2+ channels. Our current findings show that it is necessary to study the possibility of amphetamine perturbing reproduction in females.

12-Week Inspiratory Muscle Training Improves Respiratory Muscle Strength in Adult Patients with Stable Asthma: A Randomized Controlled Trial.

This study aims to investigate and compare the effects of conventional breathing exercises and an inspiratory muscle training intervention on clinical symptoms in asthma patients. Sixty asthma patients (40-65 years old) were randomly assigned to either the conventional breathing exercises (BTE) or inspiratory muscle training (IMT) group for a 12-week intervention period. Outcome measurements were performed before and after the intervention, including the spirometry data, maximal inspiratory and expiratory pressures (PImax and PEmax), asthma control test, asthma control questionnaire, six-minute walk test, and three-day physical activity log, were recorded. PImax expressed as % of predicted value controlled for age and gender in healthy subjects (% predicted) increased by 16.92% (82.45% to 99.38%, p < 0.05) in the BTE group and by 29.84% (71.19% to 101.03%, p < 0.05) in the IMT group. Except for forced vital capacity, which was reduced in the BTE group, all other measured variables improved in both groups, and no statistically significant between-group differences were found. IMT appears to be more effective than breathing exercise intervention in promoting improvements in respiratory muscle strength. IMT may act as an alternative to conventional breathing exercises for middle-aged and elderly asthma patients.

Anti-fatigue Effects of Santé Premium Silver Perch Essence on Exhaustive Swimming Exercise Performance in Rats.

Aim: Fish soup is a traditional Chinese food usually offered as a healthy supplement to elders, pregnant women and persons who just had surgery. Silver perch (Santé premium silver perch essence, SPSPE) extract contains various quality proteins, collagen, minerals, trace elements, and branch chain amino acids (BCAA) that could help individuals recover from exhaustion and control body weight. However, there are very limited studies exploring the effects of fish extracts on exercise performance and fatigue, and relevant physiological mechanisms. Therefore, the purpose of this study was to investigate the effects of chronic SPSPE administration on exhaustive exercise performance. Method: Male Wistar rats weighing around 250 g were divided into 4 groups: Control, 1X SPSPE (6.2 ml/kg), 2X SPSPE (12.4 ml/kg) and 5X SPSPE (31.0 ml/kg). Rats were administrated SPSPE by oral gavage feeding every day for 33 days. Their body weight were measured every week. Before and after the exhaustive swimming test, the blood was collected for circulating lactate, glucose, ammonia, hormones, and myoglobin analysis. Rats were sacrificed after performing an exhaustive swimming exercise test. The liver tissues were collected for glycogen content and H&E staining. Results: After the administration of 1X and 5X SPSPE, swimming fatigue was significantly delayed (p = 0.024). There was no difference in the hormone plasma level between the control and SPSPE groups. The induction of plasma corticosterone and TBARS by exhaustive swimming exercise could be decreased by SPSPE administration. The increased plasma myoglobin concentration from exhaustive swimming exercise was weakened by SPSPE supplementation. The higher glycogen sparing contained in liver tissue was observed in SPSPE-treated groups (p < 0.05). Conclusion: SPSPE could efficiently delay swimming fatigue through sparing of liver glycogen and attenuation of plasma TBARS, myoglobin induction by exhaustive exercise. Our findings provide a scientific-based fundamental information and better understanding for developing a fish extract-based anti-fatigue supplement.

Menstrual phase and ambient temperature do not influence iron regulation in the acute exercise period.

The current study investigated whether ambient heat augments the inflammatory and postexercise hepcidin response in women and if menstrual phase and/or self-pacing modulate these physiological effects. Eight trained females (age: 37 ± 7 yr; V̇o2max: 46 ± 7 mL·kg-1·min-1; peak power output: 4.5 ± 0.8 W·kg-1) underwent 20 min of fixed-intensity cycling (100 W and 125 W) followed by a 30-min work trial (∼75% V̇o2max) in a moderate (MOD: 20 ± 1°C, 53 ± 8% relative humidity) and warm-humid (WARM: 32 ± 0°C, 75 ± 3% relative humidity) environment in both their early follicular (days 5 ± 2) and midluteal (days 21 ± 3) phases. Mean power output was 5 ± 4 W higher in MOD than in WARM (P = 0.02) such that the difference in core temperature rise was limited between environments (-0.29 ± 0.18°C in MOD, P < 0.01). IL-6 and hepcidin both increased postexercise (198% and 38%, respectively); however, neither was affected by ambient temperature or menstrual phase (all P > 0.15). Multiple regression analysis demonstrated that the IL-6 response to exercise was explained by leukocyte and platelet count (r2 = 0.72, P < 0.01), and the hepcidin response to exercise was explained by serum iron and ferritin (r2 = 0.62, P < 0.01). During exercise, participants almost matched their fluid loss (0.48 ± 0.18 kg·h-1) with water intake (0.35 ± 0.15 L·h-1) such that changes in body mass (-0.3 ± 0.3%) and serum osmolality (0.5 ± 2.0 osmol·kgH2O-1) were minimal or negligible, indicating a behavioral fluid-regulatory response. These results indicate that trained, iron-sufficient women suffer no detriment to their iron regulation in response to exercise with acute ambient heat stress or between menstrual phases on account of a performance-physiological trade-off.

Influences of Recreational Tennis-Playing Exercise Time on Cardiometabolic Health Parameters in Healthy Elderly: The ExAMIN AGE Study.

BACKGROUND: Aging and chronic degeneration are the primary threats to cardiometabolic health in elderly populations. Regular appropriate exercise would benefit the advanced aging population. PURPOSE: This study investigates whether the degree of weekly tennis participation exhibits differences in primary cardiometabolic parameters, including arterial stiffness, inflammation, and metabolic biomarkers in elderly tennis players. METHODS: One hundred thirty-five long-term participants in elder tennis (>50 years old) were initially screened. Twenty-six eligible and voluntary subjects were divided into high tennis time group (HT) (14 ± 1.3 h/week) and low tennis time group (LT) (4.5 ± 0.7 h/week) by stratification analysis based on the amount of tennis playing activity time. The brachial-ankle pulse wave velocity (baPWV), blood pressure, ankle-brachial index (ABI), blood metabolic biomarkers, and insulin resistance were measured to compare the difference between HT and LT groups. RESULTS: The baPWV was significantly lower in the HT group than that in the LT group (1283.92 ± 37.01 vs. 1403.69 ± 53.71 cm/s, p < 0.05). We also found that the HT insulin-resistant homeostasis model assessment (HOMA-IR) was significantly lower than that of LT (1.41 ± 0.11 vs. 2.27 ± 0.48 µIU/mL, p < 0.05). However, the blood lipid biomarkers (glucose, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride) were not statistical different between HT and LT groups (p > 0.05). CONCLUSION: We demonstrated that under the condition of similar daily physical activity level, elderly with a higher time of tennis-playing (HT group) exhibited relatively lower arterial stiffness (lower PWV) and lower insulin resistance compared to those with lower time tennis-playing (LT).