Effects of mild hyperbaric oxygen therapy on timing sequence recovery of muscle fatigue in chinese university male athletes.

Objectives: This study aimed to investigate the timing sequence recovery effects of single and repeated Mild Hyperbaric Oxygen Therapy (MHOT) on muscle fatigue induced by cycling exercise through a comprehensive set of parameters. Methods: This study employed a controlled crossover design involving 12 Chinese secondary national-level male athletes. Each participant completed two identical trials over six days. Each trial consisted of a 90-min cycling exercise followed by either a Control (CON) intervention (1 atm absolute (ATA), 20.9 % oxygen, 60 min) or MHOT intervention (1.25 ATA, 26%-28 % oxygen, 60 min). Various physiological parameters including Rating of Perceived Exertion (RPE), Heart Rate (HR), Peripheral Oxygen Saturation (SpO2), Perfusion Index (PI%), Creatine Kinase (CK), Lactate Dehydrogenase (LDH), Lactic Acid (LA), Blood Urea Nitrogen (BUN), Superoxide Dismutase (SOD), Malondialdehyde (MDA), and Standing Long Jump Distance (SLJ) were measured at six different time points throughout the trials. Results: RPE revealed that the MHOT group experienced reduced subjective fatigue in comparison to the CON group (P < 0.05). Additionally, MHOT demonstrated quicker recovery in HR and PI% compared to the CON group (P < 0.05). Regarding CK, LA, BUN, SOD, and MDA levels, the MHOT group exhibited accelerated recovery post-6 intervention and at the 24-h mark after six interventions, showing significant improvement over the CON group (P < 0.05). However, no notable disparity was observed between groups concerning SpO2, LDH, and SLJ. Conclusions: Both single and repeated sessions of MHOT demonstrated efficacy in alleviating subjective fatigue and promoting recovery of heart rate and blood perfusion following muscle fatigue, ensuring parallel structure and consistency in their effects. Repeated MHOT sessions (six times) exhibit a significant reduction in levels of blood markers associated with muscle damage, metabolites, and oxidative stress. However, the impact of a single MHOT intervention was less pronounced.

Better Life's Essential 8 contributes to slowing the biological aging process: a cross-sectional study based on NHANES 2007-2010 data.

Objective: To investigate the relationship between Life's Essential 8 (LE8) and Phenotypic Age Acceleration (PhenoAgeAccel) in United States adults and to explore the impact of LE8 on phenotypic biological aging, thereby providing references for public health policies and health education. Methods: Utilizing data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2010, this cross-sectional study analyzed 7,339 adults aged 20 and above. Comprehensive assessments of LE8, PhenoAgeAccel, and research covariates were achieved through the integration of Demographics Data, Dietary Data, Laboratory Data, and Questionnaire Data derived from NHANES. Weighted generalized linear regression models and restricted cubic spline plots were employed to analyze the linear and non-linear associations between LE8 and PhenoAgeAccel, along with gender subgroup analysis and interaction effect testing. Results: (1) Dividing the 2007-2010 NHANES cohort into quartiles based on LE8 unveiled significant disparities in age, gender, race, body mass index, education level, marital status, poverty-income ratio, smoking and drinking statuses, diabetes, hypertension, hyperlipidemia, phenotypic age, PhenoAgeAccel, and various biological markers (p < 0.05). Mean cell volume demonstrated no intergroup differences (p > 0.05). (2) The generalized linear regression weighted models revealed a more pronounced negative correlation between higher quartiles of LE8 (Q2, Q3, and Q4) and PhenoAgeAccel compared to the lowest LE8 quartile in both crude and fully adjusted models (p < 0.05). This trend was statistically significant (p < 0.001) in the full adjustment model. Gender subgroup analysis within the fully adjusted models exhibited a significant negative relationship between LE8 and PhenoAgeAccel in both male and female participants, with trend tests demonstrating significant results (p < 0.001 for males and p = 0.001 for females). (3) Restricted cubic spline (RCS) plots elucidated no significant non-linear trends between LE8 and PhenoAgeAccel overall and in gender subgroups (p for non-linear > 0.05). (4) Interaction effect tests denoted no interaction effects between the studied stratified variables such as age, gender, race, education level, and marital status on the relationship between LE8 and PhenoAgeAccel (p for interaction > 0.05). However, body mass index and diabetes manifested interaction effects (p for interaction < 0.05), suggesting that the influence of LE8 on PhenoAgeAccel might vary depending on an individual's BMI and diabetes status. Conclusion: This study, based on NHANES data from 2007-2010, has revealed a significant negative correlation between LE8 and PhenoAgeAccel, emphasizing the importance of maintaining a healthy lifestyle in slowing down the biological aging process. Despite the limitations posed by the study's design and geographical constraints, these findings provide a scientific basis for the development of public health policies focused on healthy lifestyle practices. Future research should further investigate the causal mechanisms underlying the relationship between LE8 and PhenoAgeAccel and consider cross-cultural comparisons to enhance our understanding of healthy aging.

Association between dietary and behavioral-based oxidative balance score and phenotypic age acceleration: a cross-sectional study of Americans.

OBJECTIVES: In light of the rise in the global aging population, this study investigated the potential of the oxidative balance score (OBS) as an indicator of phenotypic age acceleration (PhenoAgeAccel) to better understand and potentially slow down aging. METHODS: Utilizing data from the National Health and Nutrition Examination Survey collected between 2001 and 2010, including 13,142 United States adults (48.7% female and 51.2% male) aged 20 and above, OBS and PhenoAgeAccel were calculated. Weighted generalized linear regression models were employed to explore the associations between OBS and PhenoAgeAccel, including a sex-specific analysis. RESULTS: The OBS demonstrated significant variability across various demographic and health-related factors. There was a clear negative correlation observed between the higher OBS quartiles and PhenoAgeAccel, which presented sex-specific. RESULTS: the negative association between OBS and PhenoAgeAccel was more pronounced in male than in female. An analysis using restricted cubic splines revealed no significant non-linear relationships. Interaction effects were noted solely in the context of sex and hyperlipidemia. CONCLUSIONS: A higher OBS was significantly associated with a slower aging process, as measured by lower PhenoAgeAccel. These findings underscore the importance of OBS as a biomarker in the study of aging and point to sex and hyperlipidemia as variables that may affect this association. Additional research is required to confirm these results and to investigate the biological underpinnings of this relationship.

Water Intake and Handgrip Strength in US Adults: A Cross-Sectional Study Based on NHANES 2011-2014 Data.

This study aimed to examine the relationship between daily total intake of water (DTIW) and handgrip strength (HGS) among US adults and to explore the impact of water intake on muscle function and health, providing a reference for public health policies and health education. Using the data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014, a cross-sectional survey design was adopted to analyze 5427 adults (48.37% female and 51.63% male) aged 20 years and above. DTIW was assessed using two non-consecutive 24 h dietary recall interviews, and the HGS level was measured using a Takei Dynamometer. Weighted generalized linear regression models and restricted cubic spline plots were used to analyze the linear and nonlinear associations between DTIW and HGS level and to conduct a gender subgroup analysis and an interaction effect test. The results showed that there were significant differences in HGS and other characteristics among different quartile groups of DTIW (p < 0.05). There was a significant nonlinear trend (exhibiting an inverted U-curve) between DTIW and HGS (p for nonlinear = 0.0044), with a cut-off point of 2663 g/day. Gender subgroup analysis showed that the nonlinear trend (exhibiting an inverted U-curve) was significant only in males (p for nonlinear = 0.0016), with a cut-off point of 2595 g/day. None of the stratified variables had an interaction effect on the association between DTIW and HGS (p for interaction > 0.05). In conclusion, this study found a nonlinear association between DTIW and HGS levels, as well as a gender difference. This finding provides new clues and directions for exploring the mechanism of the impact of DTIW on muscle function and health and also provides new evidence and suggestions for adults to adjust their water intake reasonably.

Effects of high-/low-temperature and high-altitude hypoxic environments on gut microbiota of sports people: A retrospective analysis.

As an invisible "endocrine organ", gut microbiota is widely involved in the regulation of nervous system, endocrine system, circulatory system, and digestive system. It is also closely related to host health and the occurrence of many chronic diseases. Relevant literature shows that high temperature, low temperature, and high-altitude hypoxia may have negative effects on commensal microorganisms. The stimulation of exercise may aggravate this reaction, which is related to the occurrence of exercise-induced fever and gastrointestinal and respiratory diseases. The intervention of probiotics can alleviate the above problems to a certain extent. Therefore, this paper takes exercise in a special environment as the starting point, deeply analyses the intervention effect and potential mechanism of probiotics, and provides the theoretical basis and reference for follow-up research and application of probiotics in sports science.

Exercise combined with heat treatment improves insulin resistance in diet-induced obese rats.

Insulin resistance is a risk factor for various cardiovascular diseases, which seriously threaten human health. Thus, finding a safe, effective and economical strategy to treat insulin resistance is urgently needed. This study aimed to investigate the effects of exercise combined with heat treatment on the insulin sensitivity in skeletal muscle of diet-induced obese (DIO) rats. Obese rats were induced by a 10-week high-fat diet and were randomly divided into normal temperature + control (NC), normal temperature + exercise (NE), heat treatment + control (HC) and heat treatment + exercise (HE) groups for 7 weeks of incremental load endurance exercise and heat treatment (exposure to a high-temperature environment room). At the end of the 7-week intervention, we measured fasting blood glucose, serum fasting insulin, serum leptin, serum adiponectin, protein expression of HSF1/HSP27 and JAK2/STAT3 pathway in soleus (primarily composed of slow-twitch fibres) and extensor digitorum longus (primarily composed of fast-twitch fibres) muscles. The results showed that exercise combined with heat treatment can effectively improve insulin resistance by regulating HSF1/HSP27 and JAK2/STAT3 pathways in the slow-twitch muscle of DIO rats. Importantly, exercise combined with heat treatment is more effective in improving insulin resistance in DIO rats than exercise or heat treatment alone. Low-moderate intensity exercise that stimulates slow-twitch muscle, combined with heat treatment is an effective strategy to treat insulin resistance.

Temperature-dependent metabolite orchestration to acute submaximal exercise indicates cardiorespiratory fitness in humans.

AIMS: Cardiorespiratory fitness (CRF), an important biomarker of human health, is impaired in cold environment compared to thermoneutral condition. The study aimed to investigate the role of metabolome response to acute exercise in regulation of CRF at different ambient temperatures. MAIN METHODS: A total of 27 young adults were recruited, and each subject underwent a cardiopulmonary exercise test (CPET) and a constant load submaximal exercise at both room temperature (25 °C) and cold temperature (0 °C). The serum samples were collected before and immediately after constant load exercise. KEY FINDINGS: Acute cold exposure decreased CRF by 41 %, accompanied by a metabolic shift to anaerobic respiration. It also decreased VO2 and increased respiratory quotient during constant load exercise. Metabolome profiling revealed that acute exercise reprogrammed serum metabolome in an ambient temperature-dependent manner. Specifically, exercise increased a cluster of fatty acids during cold exposure, possibly due to impaired fatty acid oxidation. The correlations between metabolite responses to acute exercise and exercise parameters were analyzed using partial least squares regression and machine learning, revealing that metabolite responses to acute exercise were highly correlated with exercise parameters and predictive of CRF. Among the contributors, tryptophan and its metabolites stood out as important ones. SIGNIFICANCE: These results suggested that the metabolite responses to acute submaximal exercise unmasks the exercise performance at different ambient temperatures, highlighting the role of metabolite orchestration in the physiological regulation of CRF.

Hydration monitoring and rehydration guidance system for athletes based on urine color's L*a*b* parameters.

Maintaining proper hydration is essential for athletes to sustain optimal performance and preserve their physical health. Existing studies have confirmed that urine color is one of the effective indicators for the subjective evaluation of athletes' hydration through the urine color chart. However, the use of urine color charts to evaluate hydration is easily affected by the test environment, urine container and subjective feeling. At present, there are few hydration monitoring instruments based on quantitative analysis of urine color. In recent years, the L*a*b* color model has been widely used in the objective quantitative analysis of color. The L* value represents the luminance change from black to white, the a* value represents the chromaticity change from green to red, and the b* value represents the chromaticity change from blue to yellow. Our previous research has confirmed that the urine color b ∗ value is an effective new indicator to evaluate the hydration of athletes. The research team developed a urine hydration monitoring and rehydration guidance system based on the urine color's L*a*b* parameters via wireless network technology and digital image technology. The hardware structure of the system is composed of a cuvette, a standard light source, a camera, an image collector, a host system, and a touch screen system. The system software is composed of functional modules, such as user information, image acquisition, image processing, and image recognition. The system operation process includes starting the system, filling in basic information, putting the sample, testing the sample, local data review, local data upload, and cloud data review. The system exhibits stable performance, a friendly operation interface, and simple and fast testing. It can objectively and accurately evaluate the hydration of athletes and provide personalized rehydration guidance. The system offers a new method for solving practical problems in sports training, and it has broad application prospects.

Effects of mixed-cooling strategies on executive functions in simulated tennis in hot and humid conditions.

This study aimed to investigate the effects of mixed-cooling strategies, which combines external (cooling vest + neck cooled collar) and internal cooling (cold sports drink ingestion) on measures of executive function during simulated tennis in hot/humid conditions. In a counterbalanced design (randomised order), eight males undertook two trials [one with the mixed-cooling strategy, (MCOOL condition) and another without (CON condition)] in a climate chamber (36.5°C, 50% relative humidity). All subjects completed an intermittent treadmill protocol simulating a three-set tennis match with a 90-second break during odd-numbered games and 120-second breaks between sets, in accordance with the activity profile and International Tennis Federation rules. The mixed-cooling strategies were adopted before test and break time during the simulated tennis match. Stroop task, 2-back task, More-odd shifting task, gastrointestinal temperature (Tgi), skin temperature, blood lactic acid (BLA), heart rate, urine specific gravity (USG), sweat rate (SR), thermal sensation (TS) and perceived exertion (RPE) were measured. Results showed that the mean exercise time was longer in the MCOOL condition than in the CON condition. The SR was greater in CON trial compared with that in MCOOL trial. Results of two-way analysis of variance with repeated measures revealed that time×condition interactions were significant in BLA, Stroop response time, and switch cost of the more-odd shifting task. There were main effects of condition for Tgi, HR, TS, RPE, BLA, Stroop response time, and switch cost of the more-odd shifting task. In a hot/wet environment, pre- and intermittent mixed-cooling strategies can significantly improve exercise time and measures of executive function of tennis players in a simulated tennis match.

Cryotherapy on Subjective Sleep Quality, Muscle, and Inflammatory Response in Chinese Middle- and Long-Distance Runners After Muscle Damage.

ABSTRACT: Qu, C, Wu, Z, Xu, M, Lorenzo, S, Dong, Y, Wang, Z, Qin, F, and Zhao, J. Cryotherapy on subjective sleep quality, muscle, and inflammatory response in Chinese middle- and long-distance runners after muscle damage. J Strength Cond Res 36(10): 2883-2890, 2022-The purpose of this investigation was to explore the effects of cold-water immersion (CWI), contrast-water therapy (CWT), and whole-body cryotherapy (CRY) on subjective sleep quality, muscle damage markers, and inflammatory markers in middle- and long-distance runners after muscle damage. Twelve male runners from Beijing Sport University completed a muscle damage exercise protocol and were treated with different recovery methods (CWI, CWT, CRY, or control [CON]) immediately after exercise and at 24-, 48-, and 72-h postexercise. The Pittsburgh Sleep Quality Index questionnaire score, lactate dehydrogenase (LDH) activity, myoglobin (Mb) activity, interleukin-6 (IL-6) activity, and soluble intercellular adhesion molecule-1 (sICAM-1) activity were measured at 7 time points (preexercise; immediately postexercise; and at 1-, 24-, 48-, 72-, and 96-h postexercise). Pittsburgh Sleep Quality Index scores indicated that the CRY condition had improved sleep quality compared with the CON and CWI conditions (p < 0.05). In terms of LDH activity, the CRY and CWT conditions had improved recovery compared with the CON and CWI conditions (p < 0.05). In terms of Mb activity, the CRY condition exhibited improved recovery compared with that of the CON and CWI conditions (p < 0.05), and the CWT condition showed better recovery than that of the CON condition (p < 0.05). In terms of IL-6 activity, the CRY condition showed improved recovery compared with the CWI condition (p < 0.05). Finally, in terms of sICAM-1 activity, the CRY condition had enhanced recovery compared with the other 3 conditions (p < 0.05). The results from this study suggest that CRY improves subjective sleep quality and reduces muscle damage and inflammatory responses in middle- and long-distance runners. In addition, CWT reduced muscle damage and inflammatory responses, but its effects on the other parameters were inconclusive.

Validation of urine colour L*a*b* for assessing hydration amongst athletes.

Objectives: Existing studies have confirmed that urine colour through a urine colour chart is one of the effective indicators for assessing hydration. In recent years, the L*a*b* colour space has been widely used in the objective quantitative analysis of colour. The L*, a* and b* values represent the luminance change from black to white, the chromaticity change from green to red and the chromaticity change from blue to yellow, respectively. This study aimed to examine the validity of the urine colour L*a*b* parameters for assessing the level of hydration amongst athletes. Methods: The study included a total of 474 young elite athletes (251 males and 223 females, age: 24.59 ± 4.86 years). A total of 803 urine samples were collected from the subjects in various stages of hydration, including morning urine and spot urine sample during rehydration. L*a*b* parameters were measured by spectrophotometer. Hydration status was assessed via urine osmolality and urine specific gravity. Results: Urine colour b* value has a high correlation with urine specific gravity and urine osmolality (r = 0.811, 0.741, both p < 0.01); L* value has a moderate correlation with urine specific gravity and urine osmolality (r = -0.508, -0.471, both p < 0.01); there was no significant correlation between a* value and urine specific gravity, urine osmolality (p > 0.05). Whether the diagnosis of hypohydration is based on Usg ≥ 1.020 or Uosm ≥ 700 mmol/kg: The AUC of b* values were all above 0.9 and the specificity and sensitivity of b* values were high (both greater than 80%). The AUC of both L* and a* values were less than 0.5. Whether the diagnosis of hyperhydration is based on Usg ≤ 1.010 or Uosm ≤ 500 mmol/kg: The AUC of b* values were all above 0.9 and the specificity and sensitivity of b* value were high (both greater than 90%). The AUC of both L* and a* values were less than 0.5. Conclusion: These results suggested that the validity of urine colour b* value for assessing hydration amongst athletes was high, however, the validity of urine colour L* and a* values were low.

Effect of Transcranial Pulsed Current Stimulation on Fatigue Delay after Medium-Intensity Training.

The purpose of this study was to investigate the effect of transcranial pulsed current stimulation (tPCS) on fatigue delay after medium-intensity training. Materials and Methods: Ninety healthy college athletes were randomly divided into an experimental group (n = 45) and control group (n = 45). The experimental group received medium-intensity training for a week. After each training, the experimental group received true stimulation of tPCS (continuous 15 min 1.5 mA current intensity stimulation). The control group received sham stimulation. The physiological and biochemical indicators of participants were tested before and after the experiment, and finally 30 participants in each group were included for data analysis. Results: In the experimental group, creatine kinase (CK), cortisol (C), time-domain heart rate variability indices root mean square of the successive differences (RMSSD), standard deviation of normal R-R intervals (SDNN), and frequency domain indicator low frequency (LF) all increased slowly after the intervention. Among these, CK, C, and SDNN values were significantly lower than those in the control group (p < 0.05). Testosterone (T), T/C, and heart rate variability frequency domain indicator high frequency (HF) in the experimental group decreased slowly after the intervention, and the HF value was significantly lower than that in the control group (p < 0.05). The changes in all of the indicators in the experimental group were smaller than those in the control group. Conclusion: The application of tPCS after medium-intensity training enhanced the adaptability to training and had a significant effect on the maintenance of physiological state. The application of tPCS can significantly promote the recovery of autonomic nervous system function, enhance the regulation of parasympathetic nerves, and delay the occurrence of fatigue.

Elastic-Electric Coefficient-Sensitive Hydrogel Sensors toward Sweat Detection.

The complex and multivariate biological systems and environment are challenging the development of related detection and analysis. It calls for the multiresponsive and facile sensing material and method for multi-analyte identification. In this work, we proposed an elastic-electric coefficient sensitivity strategy with hydrogel [amino trimethylene phosphonic acid-assisted poly(vinyl alcohol)] to achieve discriminative analysis of various chemicals. Elastic sensitivity based on the Hofmeister effect and electric sensitivity based on hydrated ion migration are explored in detail. With a rational design, the elastic-electric coefficient-sensitive hydrogel can qualify and quantify various kinds of chemicals (cations, anions, amino acids, saccharides, and lactate). The facile hydrogel sensor realized complicated sweat recognition and can be used in various applications such as environment monitoring, disease diagnosis, and athletic training optimization.

Amelioration of Ambient Particulate Matter (PM2.5)-Induced Lung Injury in Rats by Aerobic Exercise Training.

Ambient particulate matter (PM2.5), as an inflammation-inducing factor, increases the prevalence of lung injury. The aim of this study was to examine the protective effect and mechanism of aerobic exercise on PM2.5 exposure-induced lung injury. Forty Wistar rats were randomly divided into four groups: sedentary+PM2.5 exposure, exercise+PM2.5 exposure, sedentary, and exercise groups. All rats in the exercise-related groups underwent 8-week aerobic interval treadmill training (5daysweek-1, 1hday-1). PM-exposed rats were exposed to ambient PM2.5 (6h day-1) for 3weeks after the 8-week exercise intervention. Then, ventilation function, histopathological changes, and inflammation responses of pulmonary tissue were examined. Results showed that PM2.5 exposure induced lung injury as manifested by decreased pulmonary function, abnormal histopathological changes, and increased pro-inflammatory cytokine levels (tumor necrosis factor-α and Interleukin-1α). Aerobic exercise alleviated the airway obstruction, reduced respiratory muscle strength, bronchial mucosal exfoliation, ultrastructure damage, and inflammatory responses induced by PM2.5 in exercise-related groups. The benefits of exercise were related with the downregulation of p38-mitogen-activated protein kinase (MAPK), and the subsequent inhibition of the pathways of the cyclooxygenase 2 (COX-2) product, prostaglandin E2 (PGE2). Thus, pre-exercise training may be an effective way to protect against PM2.5-induced lung inflammatory injury in rats.

Comparative Study of the Effects of Tai Chi and Square Dance on Immune Function, Physical Health, and Life Satisfaction in Urban Empty-Nest Older Adults.

Objective: To compare the effects of Tai Chi and Square dance on immune function, physical health, and life satisfaction in urban, empty-nest older adults. Methods: This cross-sectional study included 249 older adults (60-69 years) who were categorized into Tai Chi (n = 81), Square dance (n = 90), and control groups (n = 78). We evaluated immunoglobulin G (IgG) and interleukin-2 (IL-2) levels by enzyme-linked immunosorbent assay (ELISA), natural killer (NK) cell cytotoxicity by MTT assay, physical health indices by physical fitness levels, and life satisfaction by Life Satisfaction Index A (LSIA) scores. Results: Immune function, physical health, and life satisfaction in older adults in the Tai Chi and Square dance groups were significantly better than those in the control group (P < 0.05). Regarding immune function and physical health, the Tai Chi group exhibited significantly higher levels of IgG (15.41 ± 0.26 g/L vs. 11.99 ± 0.35 g/L, P < 0.05), IL-2 (4.60 ± 0.20 ng/mL vs. 4.45 ± 0.21 ng/mL, P < 0.05), and NK cell cytotoxicity (0.28 ± 0.02 vs. 0.22 ± 0.02, P < 0.05) than the square dance group, significantly lower waist-to-hip ratio (0.87 ± 0.02 vs. 0.89 ± 0.02, P < 0.05), resting pulse (78.4 ± 4.6 beats/min vs. 81.0 ± 3.1 beats/min, P < 0.05), systolic blood pressure (132.0 ± 5.2 mmHg vs. 136.2 ± 3.2 mmHg, P < 0.05), diastolic blood pressure (80.0 ± 2.6 mmHg vs. 83.0 ± 2.7 mmHg, P < 0.05), and significantly higher vital capacity (2978.0 ± 263.0 mL vs. 2628.3 ± 262.8 mL, P < 0.05) and duration of one-leg standing with eyes closed (16.2 ± 1.9 s vs. 12.0 ± 1.7 s). However, there was no significant difference in LSIA scores between the Tai Chi and Square dance groups (12.05 ± 1.96 vs. 13.07 ± 1.51, P > 0.05). Further, there was a significant correlation between LSIA scores and immune function (r = 0.50, P = 0.00) and physical health (r = 0.64, P = 0.00). Conclusion: (1) Both Tai Chi and square dance practitioners had better health outcomes, compared with sedentary individuals; (2) Tai Chi practitioners had better physical health and immune function than Square dance practitioners. (3) Tai Chi and Square dance exercises had similar effects on life satisfaction among urban empty-nest older adults. Suggestions: For urban empty-nest older adults who want to have better physical health and immune function, long-term Tai Chi exercise may be a better choice; however, those who are concerned about life satisfaction can choose either Tai Chi or Square dance exercise.

Aerobic exercise ameliorates particulate matter-induced lung injury in aging rats.

Particulate matter 2.5 (PM2.5) is an inflammatory-inducing factor that is considered to be related to many adverse respiratory problems, especially in the elderly. This study aimed to examine whether pre-exercise training could prevent pulmonary injury induced by urban PM2.5 in aging rats and investigate its relationship with inflammatory pathways. Male Wistar rats (aged 16 months) were randomly divided into four groups: sedentary, exercise, sedentary + PM2.5 exposure, and exercise + PM2.5 exposure. All rats in exercise-related groups were treadmill-trained for 8 weeks (65%-75% VO2max for 30 min every other day). Sedentary groups' rats lived freely in cages without exercise intervention. Rats in the PM-related groups were exposed to ambient PM2.5 (4 h day-1) for 2 weeks after an 8-week exercise intervention or sedentary treatment. Finally, all rats' pulmonary function, lung morphology, degree of inflammation, and relevant protein and mRNA transcript expression levels were examined. The results indicated that PM2.5 exposure induced lung injury in the sedentary + PM2.5 exposure group, as evidenced by the deterioration of pulmonary function, histopathological characteristics, and inflammatory changes. Aerobic exercise alleviated PM2.5-induced airway obstruction, deterioration of pulmonary function, bronchial mucosal exfoliation, and inflammatory responses in aging rats. These effects in exercise groups were associated with the increased expression of intracellular 70 kDa heat shock protein (iHSP70) and the suppression of nuclear transcription factor-κB (NF-κB) activation, as confirmed by increased expression of inhibitor of NF-κB (IκBα) and a reduction in phospho-IKBα (p-IκBα), which is regulated by inhibiting kappa B kinase beta (IKKß). Taken together, aerobic pre-exercise had protective effects on lung injury and reduced vulnerability to inflammation induced by PM2.5 exposure, possibly through the toll-like receptor 4 (TLR4)/NF-κB signaling pathways mediated by the extracellular-to-intracellular HSP70 ratio. Pre-exercise training may be an effective way to protect against PM2.5-induced lung toxicity in aging individuals.

A Mixed-Method Approach of Pre-Cooling Enhances High-Intensity Running Performance in the Heat.

We investigated whether single or combined methods of pre-cooling could affect high-intensity exercise performance in a hot environment. Seven male athletes were subjected to four experimental conditions for 30 min in a randomised order. The four experimental conditions were: 1) wearing a vest cooled to a temperature of 4 ℃ (Vest), 2) consuming a beverage cooled to a temperature of 4 ℃ (Beverage), 3) simultaneous usage of vest and consumption of beverage (Mix), and 4) the control trial without pre-cooling (CON). Following those experimental conditions, they exercised at a speed of 80% VO2max until exhaustion in the heat (38.1 ± 0.6 ℃, 55.3 ± 0.3% RH). Heart rate (HR), rectal temperature (Tcore), skin temperature (Tskin), sweat loss (SL), urine specific gravity (USG), levels of sodium (Na+) and potassium (K+), rating of perceived exertion (RPE), thermal sensation (TS), and levels of blood lactic acid ([Bla]) were monitored. Performance was improved using the mixed pre-cooling strategy (648.43 ± 77.53 s, p = 0.016) compared to CON (509.14 ± 54.57 s). Tcore after pre-cooling was not different (Mix: 37.01 ± 0.27 ℃, Vest: 37.19 ± 0.33 ℃, Beverage: 37.03 ± 0.35 ℃) in all cooling conditions compared to those of CON (37.31 ±0.29 ℃). A similar Tcore values was achieved at exhaustion in all trials (from 38.10 ℃ to 39.00 ℃). No difference in the level of USG was observed between the conditions. Our findings suggest that pre-cooling with a combination of cold vest usage and cold fluid intake can improve performance in the heat.

Maximum oxygen consumption and quantification of exercise intensity in untrained male Wistar rats.

This study aimed to explore a valid test protocol for measuring VO2max in healthy untrained male Wistar rats of different ages and quantifying the exercise intensity (%VO2max) of running under different treadmill grades and speeds. The test protocols and %VO2max will provide a reference for the design of exercise intensity. We tested male Wistar rats aged 4 weeks, 10 weeks, 10 months and 16 months old with three test protocols (Procedure 1 [P1], 2 [P2] and 3 [P3]) for each age group to quantify VO2max. We analysed VO2max, respiratory exchange ratio and test duration to determine an optimal test protocol of VO2max for different age groups. We used the optimal test protocol to explore the changes in age-related VO2max. Finally, %VO2max of running under different treadmill speeds and grades was quantified. VO2max of Wistar rats decreased significantly after the age of 4 weeks (p < 0.05). The optimum VO2max can be induced by personalised protocols for different ages. In 4-week-old Wistar rats, the highest VO2max values were attained by P1 (104.4 ± 6.9 mL · kg-1 · min-1, p = 0.032). The highest VO2max value (84.7 ± 3.7 mL · kg-1 · min-1, p = 0.037) of 8-week-old Wistar rats was attained in P2. In 10-month-old Wistar rats, the highest VO2max value was obtained in P3 (63.3 ± 1.7 mL · kg-1 · min-1). This work could be used as a reference for assessing aerobic capacity in studies on exercise intervention with untrained male Wistar rats. However, the %VO2max measurements at various treadmill speeds and grades only apply to untrained male Wistar rats.

Physical Activity, Screen Time, and Emotional Well-Being during the 2019 Novel Coronavirus Outbreak in China.

We aimed to evaluate the effects of the COVID-19 lock down on lifestyle in China during the initial stage of the pandemic. A questionnaire was distributed to Chinese adults living in 31 provinces of China via the internet using a snowball sampling strategy. Information on 7-day physical activity recall, screen time, and emotional state were collected between January 24 and February 2, 2020. ANOVA, χ² test, and Spearman's correlation coefficients were used for statistical analysis. 12,107 participants aged 18-80 years were included. During the initial phase of the COVID-19 outbreak, nearly 60% of Chinese adults had inadequate physical activity (95% CI 56.6%-58.3%), which was more than twice the global prevalence (27.5%, 25.0%-32.2%). Their mean screen time was more than 4 hours per day while staying at home (261.3 ± 189.8 min per day), and the longest screen time was found in young adults (305.6 ± 217.5 min per day). We found a positive and significant correlation between provincial proportions of confirmed COVID-19 cases and negative affect scores (r = 0.501, p = 0.004). Individuals with vigorous physical activity appeared to have a better emotional state and less screen time than those with light physical activity. During this nationwide lockdown, more than half of Chinese adults temporarily adopted a sedentary lifestyle with insufficient physical activity, more screen time, and poor emotional state, which may carry considerable health risks. Promotion of home-based self-exercise can potentially help improve health and wellness.

Cryotherapy Models and Timing-Sequence Recovery of Exercise-Induced Muscle Damage in Middle- and Long-Distance Runners.

CONTEXT: Among sports-recovery methods, cold-water immersion (CWI), contrast-water therapy (CWT), and whole-body cryotherapy (WBC) have been applied widely to enhance recovery after strenuous exercise. However, the different timing effects in exercise-induced muscle damage (EIMD) after these recovery protocols remain unknown. OBJECTIVE: To compare the effects of CWI, CWT, and WBC on the timing-sequence recovery of EIMD through different indicator responses. DESIGN: Crossover study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Twelve male middle- and long-distance runners from the Beijing Sport University (age = 21.00 ± 0.95 years). INTERVENTION(S): Participants were treated with different recovery methods (control [CON], CWI, CWT, WBC) immediately postexercise and at 24, 48, and 72 hours postexercise. MAIN OUTCOME MEASURE(S): We measured perceived sensation using a visual analog scale (VAS), plasma creatine kinase (CK) activity, plasma C-reactive protein (CRP) activity, and vertical-jump height (VJH) pre-exercise, immediately postexercise, and at 1, 24, 48, 72, and 96 hours postexercise. RESULTS: For the VAS score and CK activity, WBC exhibited better timing-sequence recovery effects than CON and CWI (P < .05), but the CWT demonstrated better effects than CON (P < .05). The CRP activity was lower after WBC than after the other interventions (P < .05). The VJH was lower after WBC than after CON and CWI (P < .05). CONCLUSIONS: The WBC positively affected VAS, CK, CRP, and VJH associated with EIMD. The CWT and CWI also showed positive effects. However, for the activity and timing-sequence effect, CWT had weaker effects than WBC.