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.

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.

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.

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.

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.

Effect of aerobic exercise and different levels of fine particulate matter (PM2.5) on pulmonary response in Wistar rats.

BACKGROUND: Exposure of particulate matter of <2.5 µm (PM2.5) has been associated with adverse respiratory and the risk of inflammation. While regular physical activity (PA) reduces the risk of many adverse health effects. This study aimed to examine the protection of exercise on adverse pulmonary health induced by PM2.5 exposures in rats. METHODS: 80 Wistar rats were randomly divided into 8 groups: Sedentary (S), Exercise (E), Sedentary+ Low concentration PM2.5 exposures (S + LPM), Exercise+Low concentration PM2.5 exposures (E + LPM), Sedentary+Medium concentration PM2.5 exposures (S + MPM), Exercise+ Medium concentration PM2.5 exposures (E + MPM), Sedentary+High concentration PM2.5 exposures (S + HPM), and Exercise+ High concentration PM2.5 exposures (E + HPM). The rats in all E-related groups went through 8-week aerobic interval treadmill training (5 days/week, 1 h/day). The PM-related groups of rats were exposed to different concentration PM2.5 exposure in Beijing. After one bout of PM exposure, the pulmonary function, structure of lung tissues and several pulmonary biomarkers were observed. RESULTS: 1) Compared with S group, following changes occurred in various S + PM2.5 exposure groups: lung tissues were seriously damaged, local bleeding, pus exudation, and inflammatory cell infiltration, as well as the decline of the SOD, CAT and GSH while the incline of Penh, Ti, Te, MDA, TNF-α and IL-1ß were observed. 2) Compared with the corresponding different concentration of S + PM2.5 exposure groups, Penh, Ti, Te, MDA, TNF-α and IL-1ß were decreased and CAT and GSH were increased in related E + PM groups respectively. CONCLUSION: In summary, the results suggest that acute PM2.5 with different concentrations can cause different degrees of adverse effects on lung, especially in medium and high concentrations. The aerobic interval training improved the pulmonary function and impeded the lesion progression, which is due to effective in impeding the oxidative stress and inflammation.

Exercise and air pollutants exposure: A systematic review and meta-analysis.

This review aims to systematically review and synthesize scientific evidence for the influence of air pollution exposure and outdoor exercise on health. We conducted a literature search in the PubMed, Cochrane, EMBASE, and Web of Science for articles that evaluated the combination effect of air pollution exposure and exercise on health. Questionnaires regarding exposure history, or studies examining indoor air pollution were excluded. Each included study needs to have clear exercise intervention plan. The pooled estimates of the combination effect of air pollution exposure and outdoor exercise on health were calculated in the meta-analysis. The quality of each included study was assessed and the quality of evidence for each outcome assessed in the meta-analysis was also measured. Twenty-five studies were identified. Six studies addressed ozone exposure, four diesel exhaust exposure, six traffic-related air pollution, ten particulate matter (PM) exposure. Only peak expiratory flow (effect size [ES] = -0.238, 95% confidence interval [CI] = -0.389, -0.088) was found to be significantly decreased after exercise intervention in a polluted environment in the meta-analysis. Seven studies reported exposure to air pollutant during exercise was associated with an increased risk of airway inflammation and decrements in pulmonary function. Six studies discovered that exposure of traffic pollution or high PM during exercise may contribute to changes in blood pressure, systemic conduit artery function and micro-vascular function. The combination effect of air pollution and exercise was found to be associated with the increased risk of potential health problems of cardiopulmonary function, immune function, and exercise performance.

Serum zinc is associated with plasma leptin and Cu-Zn SOD in elite male basketball athletes.

This paper investigates the relationship between plasma trace element and plasma leptin, as well as percent fat mass, in 16 male basketball athletes. Blood samples were obtained before intensive training and 24h after intensive training to measure plasma zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), iron (Fe), and leptin levels. High-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), triglyceride (TG), total and cholesterol (TC) levels were determined using commercially available kits for humans. Subjects presented similar values in terms of age (21.1±2.2 years old), body mass index (23.9±2.00kg/m(2)), percent body fat (14.40±1.52%), plasma hemoglobin (150.1±9.4g/L), plasma Zn (17.47±1.28µmol/l), plasma Cu (13.42±1.40µmol/L), plasma Ca (2.41±0.14mmol/L), and plasma Mg (0.96±0.02mmol/L). The correlation analysis between degree of plasma leptin and plasma element contents was performed using the SPSS 16.0 software. Plasma Zn correlated positively with plasma leptin (r=0.746, P<0.01), Cu-Zn SOD (r=0.827, P<0.01), and negatively with percent fat mass (r=-0.598, P<0.05) under no-training conditions. Meanwhile, plasma Cu, Ca, Mg, and Fe did not correlate with plasma leptin or percent fat mass (P>0.05). In conclusion, plasma Zn may be involved in the regulation of plasma leptin and may serve as a lipid-mobilizing factor in Chinese men's basketball athletes.

[Environment of high temperature or air particle matter pollution, and health promotion of exercise].

It is important to keep human health in special environment, since the special environment has different effects on health. In this review, we focused on high temperature and air particle matter environment, and health promotion of exercise. Exercise and high temperature are the main non-pharmacological therapeutic interventions of insulin resistance (IR). PGC-1α is key regulatory factor in health promotion of exercise and high temperature. The novel hormone Irisin might be the important pathway through which heat and exercise could have positive function on IR. Air particle matter (PM) is associated with onset of many respiratory diseases and negative effects of exerciser performance. However, regular exercise plays an important role in improving health of respiratory system and lowering the risk induced by PM. Furthermore, free radicals and inflammatory pathways are included in the possible mechanisms of positive physiological effects induced by exercise in air particle matter environment.