High-intensity Swimming Research Articles

The impact of exercise intensity and duration for swim training-induced adaptations in cardiac structure and function in women with mild hypertension.

This study aimed to investigate the impact of swim training intensity and duration on cardiac structure and function in mildly hypertensive women. Sixty-two mildly hypertensive women were randomized to 15 weeks of either (1) high-intensity swimming (HIS, n = 21), (2) moderate-intensity swimming (MOD, n = 21) or (3) control (CON, n = 20). Training sessions occurred three times per week. Cardiac measurements were conducted using echocardiography pre- and post-intervention. Both the HIS and MOD groups demonstrated significant within-group increases in left ventricular mass: 7.3% [1.2; 13.2] (p = 0.02) for HIS and 6.2% [0.5; 11.8] (p = 0.03) for MOD. The MOD group also demonstrated a significant increase in left ventricular internal dimension at end-diastole by 2.4% [0.2; 4.6] (p = 0.03).Post-hoc analysis of diastolic function markers revealed reduced mitral valve A velocity in both HIS (-14% [-25; -3], p = 0.02) and MOD (-13% [-23; -3], p = 0.01), leading to increased mitral valve E/A ratios of 27% [10; 47] (p = 0.003) and 22% [5; 40] (p = 0.01), respectively. Additionally, only MOD demonstrated increased left atrial diameter of 4.9% [0.7; 9.1] (p =0.02). A significant time×group effect (p = 0.02) existed for global longitudinal strain, which increased by 1.6% [0.2; 3.0] (p = 0.03) in MOD only. In conclusion, swim training for 15 weeks increased left ventricular mass and improved markers of diastolic function in mildly hypertensive women. These independent of exercise intensity and duration in mildly hypertensive women.

High-intensity interval swimming improves cardiovascular endurance, while aquatic resistance training enhances muscular strength in older adults

The aim of this study was to examine the effects of free swimming (FS), aquatic resistance training (ART), and their combination (FS&ART) on the body composition, blood pressure, and physical fitness of older adults. The study employed a randomized controlled design, comparing three experimental groups with a control group. Eighty volunteers aged between sixty and seventy years (age: 66.2 ± 2.3 years; body mass index: 25.8 ± 4.3 kg/m²) participated in the 16-week intervention, consisting of two weekly sessions. Assessments were conducted at baseline and post-intervention, including anthropometric measurements, blood pressure readings, and the Senior Fitness Test. Significant differences were found between groups in post-intervention considering the chair stand test (p = 0.017; ES = 0.125), arm curl test (p = 0.029; ES = 0.111), 8-foot up and go test (p = 0.042; ES = 0.102), and walk test − 6 min (p = 0.005; ES = 0.156). Specifically, both ART (+ 20.1%; p < 0.05) and FS&ART (+ 19.5%; p < 0.05) showed significantly greater improvements in the chair stand test compared to the control group. Similarly, ART (+ 23.1%; p < 0.05) and FS&ART (+ 18.7%; p < 0.05) performed better than the control group. FS&ART also exhibited a significant improvement over the control group in the 8-foot up-and-go test (+ 14.6%; p < 0.05). In the 6-minute walk test, FS (+ 19.4%; p < 0.05) and FS&ART (+ 15.9%; p < 0.05) both significantly outperformed the control group. This study found that FS improves cardiovascular endurance, while ART enhances muscular strength and endurance in older adults, with combined benefits for agility, suggesting integration of combined modalities into community wellness initiatives for enhanced physical fitness and health outcomes.

The relationship between maximal lactate accumulation rate and sprint performance parameters in male competitive swimmers.

This study aimed to examine the relationship between the maximal lactate accumulation rate (ċLamax) and sprint performance parameters in male competitive swimmers. Seventeen male competitive swimmers volunteered to perform a 20 m maximal front crawl sprint without pushing off the wall from a floating position. ċLamax was determined by the 20-m sprint time and blood lactate measured before and after the 20 m sprint. For the sprint performance parameter, a 50 m time trial with the front crawl swimming stroke was conducted, and the times taken from 0 to 15 m, 15-25 m, 25-35 m, and 35-45 m were analyzed. A semi-tethered swimming test was conducted to investigate the load-velocity profile of each swimmer. From the load-velocity profile, theoretical maximal velocity (V0), maximal load (L0) and relative maximal load (rL0) were examined. The slope of the load-velocity profile was also determined. According to the results, ċLamax correlated with 50 m front crawl performance (r = -.546, p < .05). Moreover, a higher ċLamax was related to faster 0-35 m section time. Furthermore, ċLamax correlated with L0 (r = .837, p < .01), rL0 (r = .820, p < .01), and load-velocity slope (r = .804, p < .01). ċLamax is a good indicator of 50 m front crawl performance in male swimmers, and higher glycolytic power contributes to the faster time at the beginning of the sprint race. ċLamax could also evaluate the ability of a swimmer to apply force to the water during high-intensity swimming.

Effects of High-Intensity Swimming Interval Training on Area, Perimeter, Circularity Index and Phenotype of Cardiac Mitochondrial Ultrastructure in Sprague Dawley Rats.

Physical inactivity impairs health by increasing morbidity. In childhood, modifiable risk factors associated with cardiovascular pathologies and related to mitochondrial function and structure are initiated by physical inactivity. The objective of this study was to analyze the effect of high-intensity swimming interval training (HIIT-swim) on cardiac mitochondrial ultrastructure in young Sprague Dawley rats compared with a sedentary group. Five-week-old Sprague Dawley rats (n = 18) were divided into a control group (C) (n = 6), a sedentary group (S) (n = 6) and an HIIT-swim group (H-s) (n = 6), the last of which performed HIIT-swim for 4 weeks. A mitochondrial ultrastructural evaluation was performed using transmission electron microscopy. In the H-s rats, mitochondrial areas and perimeters were found to be statistically significantly different from those of the C and S rats. In addition, no predominant intramitochondrial multifragmentation was observed in the mitochondria of H-s rats, but multifragmentation was evident in the mitochondria of S rats.

Apnea or normal breathing during repeated high-intensity swimming enhance sprint efficiency and which metabolic disorder?

The aim of this study was to investigate the effect of normal breath and apnea swimming on acid-base balance, physiological responses and performance during high-intensity interval training in swimming. Sixteen swimmers completed 6×50 m intervals of freestyle swimming with normal breath and apnea at maximum intensity, with 1 minute rest. Capillary blood gases (pH, PCO<inf>2</inf>, PO<inf>2</inf>, HCO<inf>3</inf>, Hct, Hb) were collected at four (4) measurement time points: 1) at rest once; 2) at rest just after the 3rd repetition; 3) at finish; and 4) at 10 min of recovery. Heart rate (HR) during swimming, lactate acid (La) concentration and swimming time (t<inf>50</inf>) were measured. Our study showed uncompensated metabolic acidosis due to increased lactic acidosis in both breathing conditions, more pronounced in apnea, and faster swimming times in apnea without different heart rate responses. Apnea during repetitive high intensity long distance interval 50 m freestyle swimming causes uncompensated metabolic acidosis but improves sprint performance.

10 weeks low intensity treadmill exercise intervention ameliorates motor deficits and sustains muscle mass via decreasing oxidative damage and increasing mitochondria function in a rat model of Parkinson's disease

AimsParkinson's disease (PD) is characterized by loss of dopamine neurons in the brain, which leads to motor dysfunction; excessive inflammation induces neuronal death. This study aimed to determine the most effective exercise modality to improve motor dysfunction in PD by comparing three different exercise regimens (low-intensity treadmill, high-intensity treadmill, and swimming). Materials and methodsThe rat model for PD was established through stereotaxic surgery, inducing unilateral 6-OHDA (6-hydroxydopamine) lesions. The low-intensity treadmill regimen exerted better protective effects on neurological and motor functions in a rat model of unilateral 6-OHDA-induced PD compared to high-intensity treadmill and swimming. The most suitable exercise regimen and the optimal duration of daily exercise (15 or 30 min) on motor activity and oxidative stress parameters were evaluated. Key findingsComparison of 15 and 30 min low-intensity treadmill regimens (10 m/min) revealed 30 min daily exercise was the optimal duration and had more favorable impacts on neurological and motor function. Furthermore, we assessed the neuroprotective effects of exercising for 15 and 30 min per day for either four or ten weeks; 30 min of daily exercise for ten weeks improved mitochondrial function, the antioxidant defense system, neurotrophic factors, and muscle mass, and thereby provided protection against dopaminergic neuron loss, and motor dysfunction in rats with 6-OHDA-induced PD. Significance30 min of daily low-intensity treadmill exercise over 10 weeks resulted in heightened mitochondrial function in both muscle and brain tissues, therefore, yielded a neuroprotective effect against the loss of dopaminergic neurons and motor dysfunction in PD rats.

Sharia Swimming Pool: A Practice and the Factors that Affect Consumers

The swimming pool is a part of tourism, entertainment, and sports activities. The development of halal tourism demands swimming pool facilities that can better meet Sharia principles that benefit Muslim consumers. This study aims to reveal Sharia swimming pool management practices and explore why its customers choose Sharia swimming pools over conventional swimming pools. This research was conducted to reveal the halal lifestyle that has penetrated halal tourism, including swimming pools based on Sharia principles. This study uses a phenomenological approach to reveal the phenomenon of swimming pool practices and factors that affect its customers. This study interviewed 15 people with characteristics of high-intensity Sharia swimming pool use. It revealed that Islamic pool management practices include rules for members to enter, swimwear, facilities, and services provided. This study explores the factors influencing Islamic pool consumers by grouping them internally and externally. Internal factors impacting Sharia swimming pool users include comfort, halal lifestyle, and health. At the same time, the support of facilities, encouragement from others, and unpleasant experiences in public or traditional swimming pools are part of external factors. This study is expected to become a reference for Sharia swimming pool management practices and evidence of the findings of factors that encourage consumers to choose Sharia swimming pools.

Research Trends on Atopic Dermatitis an Autoimmune Disease and Exercise

PURPOSE: Autoimmune diseases attack the organs and tissues of the body because of abnormalities in the immune system, causing health issues such as inflammation and atopic dermatitis. Atopic dermatitis is a chronic inflammatory skin disease with a multifactorial pathogenesis that presents with an itchy, dry dermis. Atopic dermatitis can be alleviated or worsened by environmental factors, and studies have reported that exercise has various effects on atopic dermatitis.METHODS: This review collected and analyzed data on the effects of exercise and atopic dermatitis from previous studies obtained through online databases and search engines, including PubMed, Web of Science, and Google Scholar.RESULTS: Moderate exercise has a positive effect on the health of patients with atopic dermatitis. During moderate- and high-intensity exercise, the thickness of the dermis and epidermis of atopic skin, serum immunoglobulin (Ig)E levels, and cytokine levels decreased. However, conflicting results showed that high-intensity swimming exercises increased the severity of atopic dermatitis. Additionally, patients with atopic dermatitis and lower physical activity levels showed increased disease severity.CONCLUSION: These results indicate that several exercises have therapeutic potential against atopic diseases. Further studies are required to investigate the effects of exercise on atopic dermatitis, including the limitations.

Papaya Leaf Ethanol Extract Lowers Malondialdehyde Levels, Increases Superoxide Dismutase Levels, and Increases Leydig Cell Count in Male Rats Given High-Intensity Swimming Exercise

Physical activity is any body movement that occurs due to skeletal muscle contractions that require energy expenditure. Overtraining can trigger oxidative stress due to chronic systemic hypoxia, cause an increase in systemic inflammatory response and multiorgan damage, and accelerate the aging process. The aging process is influenced by many factors, one of which is high-intensity swimming exercise which triggers the emergence of free radicals and leads to systemic oxidative stress. High-intensity swimming exercise is associated with an increase in Reactive Oxygen Species (ROS). The Papaya plant is famous for its therapeutic and nutritional properties. Papaya leaves contain secondary metabolites from papaya leaf extract including tannins, saponins, flavonoids, phenolics, and alkaloids. Papaya leaf extract has strong medicinal properties as an antibacterial, antiviral, antitumor, and antioxidant. This research is an experimental study with a post-test-only control group design. The sample in this study were male white rats (Rattus norvegicus) with an age range of 3-4 months with an average body weight range of 180-200 grams. As many as 36 rats were divided into 2 treatment groups. Treatment group 1 (P1) rats were given high-intensity swimming exercise treatment and aquabidest. Treatment group 2 (P2) rats were given high-intensity swimming exercise treatment and papaya leaf extract 60mg / 200g BB orally. Each treatment was carried out for 21 days. The data obtained will be analyzed using an independent sample T-test. The results of this study obtained: (1) the average MDA levels showed that the P1 group (1.02±0.064) was higher than the P2 group (0.86±0.44) with a value of p&lt;0.001; (2) the average SOD level in the P2 group (2.72±0.437) was higher than P1 (1.46±0.288) with p&lt;0.001; (3) the average number of Leydig cells in the P1 group (13.0±5.05) was lower than in the P2 group (30.0±5.05) with p&lt;0.001. This study concluded that papaya leaf ethanol extract in rats was able to reduce MDA levels, increase SOD levels and increase the number of Leydig cells in male rats given high-intensity swimming exercise.

Shoulder Tensiomyography and Isometric Strength in Swimmers Before and After a Fatiguing Protocol.

Shoulder muscles are active during front-crawl swimming to provide propulsion and stabilize the glenohumeral and scapulothoracic joints. Researchers have proposed that fatigue might contribute to altered activation of these muscles and represent a risk factor for injuries. Tensiomyography (TMG) might function as a noninvasive tool to detect changes in contractile measures of the skeletal muscles due to exercise-induced neuromuscular fatigue, though it has not yet been used in the shoulder muscles of swimmers. To assess the effects of a fatiguing swimming protocol on shoulder muscle TMG measures and isometric strength in competitive swimmers. Cross-sectional study. Swimming pool facility. A total of 14 young front-crawl competitive swimmers (11 males and 3 females; age = 21 ± 3 years [range, 17-26 years], height = 1.78 ± 0.06 m, mass = 73.1 ± 9.2 kg). Participants completed TMG and isometric strength assessments before and after 30-minute, high-intensity swim training. The TMG assessment was performed on 7 muscles of the shoulder according to front-crawl biomechanics and the applicability of the technique to obtain data, such as time to contraction and muscle-belly radial displacement. Isometric strength was assessed using a digital handheld dynamometer during shoulder flexion, extension, external rotation, and internal rotation. Fatigue induced a smaller radial displacement, mostly observable in latissimus dorsi (-1.0 mm; 95% CI = -1.7, -0.3 mm; P = .007) and pectoralis major muscles (-1.4 mm; 95% CI = -2.4, -0.4 mm; P = .007). Only shoulder extension showed an isometric strength reduction after the fatiguing protocol (-0.03 N/kg; 95% CI = -0.05, -0.01 N/kg; F1,13 = 4.936; P = .045; ηp2 = 0.275). This study provides preliminary evidence for the usefulness of TMG to detect fatigue-induced changes in contractile properties of the shoulder muscles in swimmers, in particular the latissimus dorsi and pectoralis major.

Sex-Specific Accumulated Oxygen Deficit During Short- and Middle-Distance Swimming Performance in Competitive Youth Athletes

IntroductionSince sex-specific accumulated oxygen deficit (AOD) during high-intensity swimming remains unstudied, this study aimed to assess AOD during 50, 100, and 200 m front-crawl performances to compare the responses between sexes and analyse the effect of lean body mass (LBM).MethodsTwenty swimmers (16.2 ± 2.8 years, 61.6 ± 7.8 kg, and 48.8 ± 11.2 kg LBM—50% males) performed 50, 100, and 200 m to determine accumulated oxygen uptake (V̇O2Ac). The swimmers also performed an incremental test from which five submaximal steps were selected to estimate the oxygen demand (V̇O2demand) from the V̇O2 versus velocity adjustment. V̇O2 was sampled using a gas analyser coupled with a respiratory snorkel. AOD was the difference between V̇O2demand and V̇O2Ac, and LBM (i.e. lean mass not including bone mineral content) was assessed by dual-energy X-ray absorptiometry (DXA).ResultsA two-way ANOVA evidenced an AOD increase with distance for both sexes: 19.7 ± 2.5 versus 24.9 ± 5.5, 29.8 ± 8.0 versus 36.5 ± 5.8, and 41.5 ± 9.4 versus 5.2 ± 11.9 ml × kg−1, respectively, for 50, 100, and 200 m (with highest values for females, P < 0.01). Inverse correlations were observed between LBM and AOD for 50, 100, and 200 m (r = − 0.60, − 0.38 and − 0.49, P < 0.05). AOD values at 10 and 30 s elapsed times in each trial decreased with distance for both sexes, with values differing when female swimmers were compared to males in the 200 m trial (at 10 s: 2.6 ± 0.6 vs. 3.4 ± 0.6; and at 30 s: 7.9 ± 1.7 vs. 10.0 ± 1.8 ml × kg−1, P < 0.05).ConclusionLBM differences between sexes influenced AOD values during each trial, suggesting that reduced muscle mass in female swimmers plays a role on the higher AOD (i.e. anaerobic energy) demand than males while performing supramaximal trials.

Effect of Eight Weeks of High-Intensity Intermittent Swimming Training on the Biochemical Factors of Lipid Metabolism and Hippocampal Memory Function of Male Rats with Non-Alcoholic Steatohepatitis (NASH)

Introduction: The molecular mechanisms of the improvement of exercise on memory are in the aura of ambiguity.Therefore, the aim of this research was studying the effect of eight weeks of high-intensity intermittent swimming training (HIIST) on the biochemical factors of lipid metabolism and hippocampal memory function of male rats with non-alcoholic steatohepatitis (NASH).&#x0D; Methods: The present study was experimental. 40 male Sprague-Dawley rats were divided into two groups: healthy (n=20) and high-fat HFD (n=20) groups. Rats in the HFD group were fed a high-fat diet for eight weeks with the aim of inducing NASH. After proving the disease in HFD group rats, the remaining rats were randomly divided into four groups: healthy-sedentary (n=9), healthy-swimming (n=9), sedentary disease (n=9) and diseased-swimming (n=9). The exercise groups performed eight weeks of HIIST (three sessions/week, each session lasting 30 minutes). At the end, FNDC5 protein was evaluated by western blot method and brain hippocampal irisin and serum FFA by ELISA method. Memory performance was measured by the water Maz-Morris behavioral test. One-way ANOVA test was used to determine the difference between groups, and Bonferroni's post hoc test was used to determine the difference between two groups (p&lt;0.05).&#x0D; Results: The findings showed that there was a significant difference in the FNDC5 protein and irisin of the brain hippocampus and serum FFA and in memory function variables between the groups (p&lt;0.05).&#x0D; Conclusion: HIIST in NASH model can activate lipid metabolism in the hippocampus of the brain and improve memory function. However, more research is needed in this field.

Pterostilbene Attenuates High-Intensity Swimming Exercise-Induced Glucose Absorption Dysfunction Associated with the Inhibition of NLRP3 Inflammasome-Induced IECs Pyroptosis

The study investigated the effect of pterostilbene (PTE) on intestinal glucose absorption and its underlying mechanisms in high-intensity swimming exercise (HISE)-treated mice. Male C57BL/6 mice were treated with PTE for 4 weeks and performed high-intensity swimming training in the last week. Intestinal epithelial cells (IECs) were pretreated with 0.5 and 1.0 μM PTE for 24 h before being incubated in hypoxia/reoxygenation condition. Intestinal glucose absorption was detected by using an oral glucose tolerance test and d-xylose absorption assay, and the levels of factors related to mitochondrial function and pyroptosis were measured via western blot analyses, cell mito stress test, and quantitative real-time polymerase chain reaction. In vivo and in vitro, the results showed that PTE attenuated HISE-induced intestinal glucose absorption dysfunction and pyroptosis in mice intestine. Moreover, PTE inhibited NLRP3 inflammasome and the mitochondrial homeostasis as well as the ROS accumulation in IEC in vitro. Additionally, knockdown of SIRT3, a major regulator of mitochondria function, by siRNA or inhibiting its activity by 3-TYP abolished the effects of PTE on pyroptosis, mitochondrial homeostasis, and ROS generation of IEC in vitro. Our results revealed that PTE could alleviate HISE-induced intestinal glucose absorption dysfunction associated with the inhibition of NLRP3 inflammasome-induced IECs pyroptosis.

High-intensity swimming alleviates nociception and neuroinflammation in a mouse model of chronic post-ischemia pain by activating the resolvin E1-chemerin receptor 23 axis in the spinal cord.

Physical exercise effectively alleviates chronic pain associated with complex regional pain syndrome type-I. However, the mechanism of exercise-induced analgesia has not been clarified. Recent studies have shown that the specialized pro-resolving lipid mediator resolvin E1 promotes relief of pathologic pain by binding to chemerin receptor 23 in the nervous system. However, whether the resolvin E1-chemerin receptor 23 axis is involved in exercise-induced analgesia in complex regional pain syndrome type-I has not been demonstrated. In the present study, a mouse model of chronic post-ischemia pain was established to mimic complex regional pain syndrome type-I and subjected to an intervention involving swimming at different intensities. Chronic pain was reduced only in mice that engaged in high-intensity swimming. The resolvin E1-chemerin receptor 23 axis was clearly downregulated in the spinal cord of mice with chronic pain, while high-intensity swimming restored expression of resolvin E1 and chemerin receptor 23. Finally, shRNA-mediated silencing of chemerin receptor 23 in the spinal cord reversed the analgesic effect of high-intensity swimming exercise on chronic post-ischemic pain and the anti-inflammatory polarization of microglia in the dorsal horn of the spinal cord. These findings suggest that high-intensity swimming can decrease chronic pain via the endogenous resolvin E1-chemerin receptor 23 axis in the spinal cord.

Changes in body composition of Wistar rats: effects of high-intensity interval training

The present study aimed to investigate the effectiveness of high-intensity interval training (HIIT) in the body composition of Wistar rats. The HIIT protocol consisted of high-intensity swimming three times a week for four weeks. There were no differences between groups as to the Lee index. However, the weights of the perigonadal (p=0.001) and retroperitoneal (p=0.026) fats were significantly different between the Control Group (CG, n=10) vs. Trained Group (TG, n=10), respectively. There was also a significant increase in the body weight of the animals in TG (16.43%) and CG (7.19%) at the end of the experiment. These findings suggested that HIIT was not sufficient to improve significantly the body composition of rats.

INFLUÊNCIA DO EXERCÍCIO DE ALTA INTENSIDADE SOBRE A APTIDÃO FÍSICA DOS NADADORES

ABSTRACT Introduction High-intensity swimming requires athletes to have explosive power, endurance, lactic acid resistance, aerobic metabolism, and other qualities. Pre-competition physical training is mainly based on high interval training, promoting ATP-CP synthesis in the body. It can enhance the resistance to lactic acid and promote lactic acid clearance. Objective This article explores the effect of high-intensity pre-competition training on the physical fitness of swimmers. The results can be used as a reference for swimmers to perform high-intensity training before the competition. Methods Eight swimmers were selected by random sampling. The study subjects received eight weeks of high-intensity training before the competition. The athletes’ gas metabolism and anaerobic thresholds were detected before and after training. At the same time, the physiological and chemical indicators of the experimental subjects were detected in this paper. Finally, this paper analyzes the experimental results by employing mathematical statistics. Results The metabolism function of the athletes changed significantly in the later period of pre-competition training (P&lt;0.05). Serum lactate concentration had no significant effect on the anaerobic threshold (P&gt;0.05). Conclusion High-intensity exercise has a particular promotion effect on improving the physical quality of swimmers. This exercise can lay a solid foundation for the swimmer’s physical fitness. Level of evidence II; Therapeutic studies – investigation of treatment results.

Effect of High-intensity Intermittent Swimming Training on peroxisome proliferator-activated receptors-αand Liver Enzymes in Non-alcoholic Steatohepatitis Male Rats

Introduction: Accumulation of fat in the liver tissue is known as the most important cause of non-alcoholic steatohepatitis, which is associated with a decrease in the protein of hepatic peroxisome proliferator-activated receptors (PPAR-α). This study aimed to investigate the effect of eight weeks of high-intensity interval training (HIST) on PPAR-α and liver enzymes in high-fat diet-induced non-alcoholic steatohepatitis rats.&#x0D; Methods: The current research was semi-experimental. 40 Spraguedauli male rats (age: 6 to 8 weeks and weight: 230 ± 20 grams) were selected and divided into two equal groups, healthy and high-fat diet (HFD). The HFD group was subjected to gavage for eight weeks with the aim of inducing the disease. Rats were divided into four groups: control-healthy (n=9), healthy-swimming (n=9), control- disease (n=9) and disease -swimming (n=9). The training groups performed HIST for eight weeks (three sessions per week, each session lasting 30 minutes). In the end, liver PPAR-α was measured by western blot analysis; and ALT, AST and GGT enzymes in serum level were measured by photometric method. One-way analysis of variance and Bonferroni's post hoc test were used to analyze the data. Significant level (P≥0.05) and all statistical methods were performed using SPSS16 software.&#x0D; Results: HIST controlled the weight gain caused by HFD and there was a significant decrease in serum ALT and AST in the healthy-swimming and sick-swimming groups compared to the control-patient group and a significant decrease in serum GGT in the healthy-swimming group compared to the control-patient (P≤0.001) and patient-swimming (P≤0.044) were observed. A significant increase in hepatic PPAR-α was observed in healthy-swimming patients compared to the control-patients (P≤0.002).&#x0D; Conclusion: HIST can control body weight and reduce liver enzymes. However, more research is needed to obtain definitive results.

Cordyceps militaris acidic polysaccharides improve learning and memory impairment in mice with exercise fatigue through the PI3K/NRF2/HO-1 signalling pathway

Excessive exercise leads to body fatigue and destroys the balance of the oxidation/oxidation resistance system in the body, thus damaging the central nervous system and reducing learning and memory ability. Nrf2 is an important transcription factor that regulates the cell oxidative stress response. Therefore, the research and development of natural antioxidants with the effect of regulating Nrf2-related signalling pathways to improve central fatigue caused by body fatigue has application value. Methods and results: Cordyceps militaris polysaccharides were extracted, isolated and purified via DEAE-cellulose 52 and Sepharose CL-6B columns to obtain two saccharides, Cordyceps militaris acidic polysaccharides (CMPB) and CMPB-b. The results of behavioural tests showed that compared with the model group, the learning and memory abilities of the CMPB-H group (800 mg/kg) mice were remarkably improved in the dark avoidance and Morris water maze tasks (p < 0.01), and the levels of fatigue metabolites and oxidative stress in the body were obviously decreased (p < 0.01). The expression level of BDNF, PI3K, Nrf2 and HO-1 proteins in the hippocampus were significantly increased (p < 0.01). In vitro experiments, compared with the PC12 oxidative stress model group, CMPB-b high-dose group (100 μg/mL) had remarkably improved oxidative stress. CMPB-b also obviously promoted the phosphorylation of PI3K and AKT proteins (p < 0.01) and the nuclear translocation of Nrf2 (p < 0.01), and significantly increased the expression of HO-1 (p < 0.01). Conclusion: CMPB can alleviate the fatigue state of high-intensity swimming mice and improve the learning and memory impairment of exercise-fatigue mice by regulating the Nrf2-related signalling pathway. Its antioxidant active component CMPB-b exerts in vitro antioxidative neurological damage by the same mechanism. Our systematic studies provide strong supporting evidence for the future use of Cordyceps militaris acidic polysaccharides in health products to improve resistance to fatigue.

Navigating a medical mystery in an elite athlete—severe dystonia induced by swimming

Dystonia is a state of involuntary muscle contractions that cause repetitive or twisting movements. It may affect one or more parts of the body and sometimes the entire body. The condition can be mild or severe. In this unusual case, high-intensity swimming triggered the episodes of atypical functional movement disorder.

Reliability Study of a Functional Test for the Offensive Agility Performance in Water Polo

The aim of the study was to develop and assess the reliability of a functional agility test containing offensive elements for water polo players. Eighteen young male (15.3 ± 0.5 years, 178.3 ± 4.7 cm, 69.4 ± 10.0 kg) water polo players with a minimum of 5 years of sport-specific experience participated in this study. The test contained reactive high-intensity short-term swimming with changes in direction and manoeuvres after perceiving unknown stimuli given by tester players, and also included a shooting task at a goal, first from 7 m and then from 5 m. Execution time and shooting efficiency were measured by two experienced water polo coaches (Evaluators A and B). All statistical analyses were calculated using SPSS. The intrarater reliability between attempts showed good reliability for both evaluators (Evaluator A: ICC: 0.87; 95% CI: 0.66–0.95 and Evaluator B: ICC: 0.88; 95% CI: 0.68–0.96). Interrater reliability between Evaluators A and B was excellent at both attempts (Attempt 1: ICC: 0.97; 95% CI: 0.93–0.99 and Attempt 2: ICC: 0.98; 95% CI: 0.91–0.99). A lack of correlation between shooting performance from 7 m and 5 m distances and execution time was observed in the protocol. The test we presented in this study was found to be a reliable measurement tool for testing offensive agility performance based on open skill nature among water polo players.