Cardiac structure and function of elite volleyball players across different playing positions.

BACKGROUND: Volleyball is a popular Olympic sport but has been little studied. Volleyball players have very distinct roles based on their playing positions. The present study aimed to investigate and compare cardiac functions and structure in elite volleyball players across different playing positions. METHODS: Left ventricular structure and function were measured using echocardiography in 60 male professional volleyball players (30.6±3.6 years) across five playing positions including libero, opposite players, outside hitters, middle blockers, and setters. RESULTS: Significant differences in most echocardiographic variables were observed among different playing positions, including left ventricular (LV) internal dimension, posterior wall thickness, intact ventricular septum, stroke volume, cardiac output, end-diastolic volume, ejection fraction, and fractional shortening (all P<0.01). End-systolic volume was not different among positions (P=0.167). The opposite players demonstrated greater LV dimension and thickness as well as systolic function than players in other positions (P<0.05). Stroke volume in the setters was significantly lower than those of the opposite players and outside hitters (P<0.05). Regression analysis showed that the playing position independently predicted most of the echocardiographic variables (P<0.05). CONCLUSIONS: LV adaptations in volleyball players vary widely according to their playing positions. The opposite players had the most pronounced LV adaptations compared with player in other positions.

Effect of Lower- versus Higher-Intensity Isometric Handgrip Training in Adults with Hypertension: A Randomized Controlled Trial.

This study compared the effects of lower- versus higher-intensity isometric handgrip exercise on resting blood pressure (BP) and associated clinical markers in adults with hypertension. Thirty-nine males were randomly assigned to one of three groups, including isometric handgrip at 60% maximal voluntary contraction (IHG-60), isometric handgrip at 30% IHG-30, or a control group (CON) that had been instructed to continue with their current activities of daily living. The volume was equated between the exercise groups, with IHG-60 performing 8 × 30-s contractions and IHG-30 performing 4 × 2-min contractions. Training was performed three times per week for 8 weeks. Resting BP (median [IQR]), flow-mediated dilation, heart rate variability, and serum markers of inflammation and oxidative stress were measured pre- and post-intervention. Systolic BP was significantly reduced for IHG-60 (−15.5 mmHg [−18.75, −7.25]) and IHG-30 (−5.0 mmHg [−7.5, −3.5]) compared to CON (p < 0.01), but no differences were observed between both the exercise groups. A greater reduction in diastolic BP was observed for IHG-60 (−5.0 mmHg [−6.0, −4.25] compared to IHG-30 (−2.0 mmHg [−2.5, −2.0], p = 0.042), and for both exercise groups compared to CON (p < 0.05). Flow-mediated dilation increased for both exercise groups versus CON (p < 0.001). IHG-30 had greater reductions in interleukin-6 and tumor necrosis factor-α compared to the other groups (p < 0.05) and CON (p = 0.018), respectively. There was a reduction in Endothelin-1 for IHG-60 compared to CON (p = 0.018). Both the lower- and higher-intensity IHG training appear to be associated with reductions in resting BP and improvements in clinical markers of inflammation and oxidative stress.

Short-Duration High-Intensity Interval Exercise Training Is More Effective Than Long Duration for Blood Pressure and Arterial Stiffness But Not for Inflammatory Markers and Lipid Profiles in Patients With Stage 1 Hypertension.

PURPOSE: The present study compared the effects of 2 different high-intensity interval training (HIIT) protocols on arterial stiffness, lipid profiles, and inflammatory markers in hypertensive patients. METHODS: Thirty hypertensive (stage 1) patients, aged 48.0 ± 3.2 yr, were randomly allocated to the short-duration HIIT (SDHIIT, n = 10), long-duration HIIT (LDHIIT, n = 10), and control (n = 10) groups. After a 2-wk preparatory phase of continuous mild training, patients in the SDHIIT group performed 8 wk of HIIT including 27 repetitions of 30-sec activity at 80% to 100% of (Equation is included in full-text article.)O2peak interspersed with 30-sec passive/active (10%-20% of (Equation is included in full-text article.)O2peak) recovery. Patients in the LDHIIT group performed 8 wk of HIIT, 32 min/session including 4 repetitions of 4-min activity at 75% to 90% of (Equation is included in full-text article.)O2peak interspersed with 4-min passive/active (15%-30% of (Equation is included in full-text article.)O2peak) recovery. Blood pressure (BP), pulse wave velocity (PWV), inflammatory markers, and lipid profiles were measured before and after training. RESULTS: Significant (P < .05) reductions in systolic blood pressure and PWV were found following 2 training protocols, though, only the changes in PWV following the SDHIIT were significantly different than those in the LDHIIT and control groups. Interleukin-6 and triglycerides decreased and interleukin-10 increased significantly (P < .01) following both HIIT programs, whereas the differences between the 2 training protocols were not statistically significant. C-reactive protein and lipids did not change significantly following HIIT. CONCLUSIONS: Performing HIIT improves systolic blood pressure and inflammatory markers in patients with stage 1 hypertension irrespective of the HIIT intensity and duration, and PWV improvement is intensity related.

Altered Neural Response Induced by Central-Fatigue in the Cortical Area During High-Intensity Interval Pedaling.

INTRODUCTION: The central-governor model explains the mechanism of endurance exercise-induced central fatigue, but high-intensity exercise-induced central fatigue has not been investigated yet. This study aimed to research how central fatigue during high-intensity intermittent pedaling alters the neural response, which results in Electroencephalography (EEG) recordings. METHODS: We assessed neural response by measuring the alternation of brainwave spectral power during an intermittent high-intensity 60-minute exercise on an ergometer cycle. The cadences were changed every 10 minutes according to intermittent pattern altering (90-120-60-120-60-90 rpm). EEG was used to analyze altering brain function. Heart Rate (HR), Blood Lactate (BL), and Rating of Perceived Exertion (RPE) were measured after the change in cadences. RESULTS: HR, BL, and RPE increased at a cadence of 120 rpm compared with 60 rpm on the ergometer cycle. The spectral power of EEG, according to cadence × brainwaves, significantly increased (P<0.01) in the alpha and beta frequency ranges with a change in cadences between 60 rpm and 120 rpm. The spectral power of the EEG significantly increased (P<0.01) over the whole frequency range from rest to warming (theta: 251%, alpha: 165%, beta: 145%) and significantly reduced in theta, alpha, and beta (theta: 176%, alpha: 142%, beta: 77%) (P≤0.01). CONCLUSION: High-intensity exercises (90 and 120 cadences) increased brain function, regardless of fatigue occurrence. High-intensity interval training (HIIT) led to altering the neural response. It would be required to investigate the usefulness of HIIT to treat some of the psychotic disorders.

The effects of short-term high-intensity interval training vs. moderate-intensity continuous training on plasma levels of nesfatin-1 and inflammatory markers.

OBJECTIVES: Exercise training is an effective method of weight management, and knowing about its influence on the hormones involved in the regulation of food intake and inflammation could be useful for body weight management. Therefore, the purpose of this study was to compare the effects of 6 weeks of high-intensity interval training (HIIT) and moderate-intensity continuous exercise training (MCT) on nesfatin-1, interleukin (IL)-6, and tumor necrosis factor alpha (TNF-α). DESIGN AND METHODS: Thirty sedentary overweight men (Mean±SD; age, 25±1 years) were divided into three (n=10) body mass index-matched groups. The participants in the training groups performed either HIIT or MCT protocols 3 days per week for 6 weeks followed by a week of detraining. RESULTS: Plasma IL-6 and TNF-α did not significantly change after training, but nesfatin increased significantly only with HIIT compared with the control group (p<0.05). In addition, fasting glucose, insulin, and homeostasis model estimated insulin resistance (HOMA-IR), decreased significantly following both HIIT and MCT training (p<0.05). After a detraining period, the plasma nesfatin-1 did not return to pre-training levels in the HIIT group. CONCLUSIONS: Both the HIIT and MCT groups had similar effects on inflammatory markers and insulin resistance in men who are overweight, but the HIIT seems to have better anorectic effects (as indicated by nesfatin) compared with MCT.

Effects of Endurance Training on the Serum Levels of Tumour Necrosis Factor-α and Interferon-γ in Sedentary Men.

Physical activity could be considered one of the factors that affect the immune system status and function. To find the relation between exercise and cytokines, we examined the possible effects of an 8-week endurance training program on the serum levels of cytokines, including tumour necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) in sedentary men. A total of 30 healthy young male volunteers were randomly divided into an endurance training group and a control group. The training group followed a specific exercise protocol (running on a treadmill for 15~30 min at 50~70% maximal heart rate) for 8 weeks and the control group did not participate in any exercise program. Venous blood samples were collected from both the groups 24 h before and 24 h and 48 h after the exercise. Repeated ANOVA was used for statistical purposes. The serum levels of TNF-α and IFN-γ were determined by ELISA. Significant (p<0.05) and non-significant (p>0.05) decreases were observed in the serum levels of IFN-γ and TNF-α, respectively, after the 8-week endurance training program. Our findings indicated that an 8-week endurance exercise may affect the serum levels of some inflammatory cytokines, suggesting the beneficial role of this training protocol in elderly population and people with certain conditions (inflammation of the vertebrae or other inflammatory diseases).

Inflammatory markers and adipocytokine responses to exercise training and detraining in men who are obese.

The purpose of this study was to compare the effects of nonlinear resistance training (NRT) and aerobic interval training (AIT), and detraining on selected inflammatory markers in men who are middle aged and obese. Subjects first were matched by aerobic capacity, age, and percentage body fat and then randomly assigned to NRT (n = 12), AIT (n = 10) and, control (CON, n = 11) groups. The experimental groups performed 3 weekly sessions for 12 weeks followed by a 4-week detraining period. Nonlinear resistance training consisted of 40-65 minutes of weight training with flexible periodization. Aerobic interval training consisted of running on a treadmill (4 × 4 minutes at 80-90% maximal heart rate, with 3-minute recovery intervals). Compared with CON, serum levels of interleukin 6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor alpha (TNF-α) did not significantly change after training, but adiponectin (ADPN) increased significantly only with AIT (5.09 ± 2.29 vs. 4.36 ± 0.84 µg·ml). No significant changes in CRP and TNF-α occurred in both training groups after detraining, but ADPN (NRT: 3.6 ± 1.2 and AIT: 3.4 ± 1.7 vs. CON: 4.7 ± 1.2 µg·ml) and IL-6 (NRT: 5.8 ± 3.3 and AIT: 5.5 ± 2.9 vs. CON: 2.3 ± 1.2 pg·ml) worsened significantly. Both the AIT and NRT were equally effective at reducing soluble intercellular cell adhesion molecule 1 (NRT: 187.2 ± 117.5 and AIT: 215.2 ± 142.4 vs. CON: 416.2 ± 205.9 ng·ml) and insulin (NRT: 4.0 ± 1.0 and AIT: 4.8 ± 2.7 vs. CON: 7.4 ± 3.0 µU·ml) levels, but these variables returned to the pretraining levels after detraining. The practical applications are that both the AIT and NRT and detraining had similar effects on most inflammatory markers in men who are obese, but the AIT seems to have better anti-inflammatory effects (as indicated by ADPN) compared with NRT.

Effects of nonlinear resistance and aerobic interval training on cytokines and insulin resistance in sedentary men who are obese.

Regular exercise training has been shown to reduce systemic inflammation, but there is limited research directly comparing different types of training. The purpose of this study was to compare the effects of nonlinear resistance training (NRT) and aerobic interval training (AIT) on serum interleukin-10 (IL-10), IL-20, and tumor necrosis factor-α (TNF-α) levels, insulin resistance index (homeostasis model assessment of insulin resistance), and aerobic capacity in middle-aged men who are obese. Sedentary volunteers were assigned to NRT (n = 12), AIT (n = 12), and (CON, n = 10) control groups. The experimental groups performed 3 weekly sessions for 12 weeks, whereas the CON grouped maintained a sedentary lifestyle. Nonlinear resistance training consisted of 40-65 minutes of weight training at different intensities with flexible periodization. Aerobic interval training consisted of running on a treadmill (4 sets of 4 minutes at 80-90% of maximal heart rate, with 3-minute recovery intervals). Serum IL-10, IL-20, and TNF-α levels did not change significantly in response to training (all p > 0.05), but IL-10:TNF-α ratio increased significantly with AIT compared with CON (2.95 ± 0.84 vs. 2.52 ± 0.65; p = 0.02). After the training period, maximal oxygen uptake increased significantly in AIT and NRT compared with CON (both p < 0.001; 46.7 ± 5.9, 45.1 ± 3.2, and 41.1 ± 4.7 ml·kg·min, respectively) and in AIT than in NRT (p = 0.001). The 2 exercise programs were equally effective at reducing insulin resistance (homeostasis model assessment for insulin resistance) (both p ≤ 0.05; AIT: 0.84 ± 0.34, NRT: 0.84 ± 0.27, and CON: 1.62 ± 0.56) and fasting insulin levels (both p ≤ 0.05; AIT: 3.61 ± 1.48, NRT: 3.66 ± 0.92, and CON: 6.20 ± 2.64 µU·ml), but the AIT seems to have better anti-inflammatory effects (as indicated by the IL-10:TNF-α ratio) compared with NRT.

Efeito do treinamento concorrente e destreinamento sobre o biomarcador anti-inflamatório e níveis de condicionamento físico em crianças obesas / Effect of concurrent training and detraining on anti-inflammatory biomarker and physical fitness levels in obese children

OBJETIVO: Examinar o efeito de 12 semanas de (3 dias/sem) de treinamento concorrente e 4 semanas de destreinamento nas concentrações séricas de adiponectina e níveis de condicionamento físico em meninos obesos sem intervenção dietética. MÉTODOS: vinte e quatro meninos saudáveis, 11-13 anos de idade com índice de massa corporal > 28 participaram voluntariamente do estudo. Estes foram divididos em dois grupos, experimental (n= 12) e controle (n=12). RESULTADOS: Concentrações de adiponectina após 12 semanas tiveram declínio significativo em ambos os grupos em comparação com o nível basal (p < 0,05). VO2 pico, flexibilidade, força, endurance de abdominais e agilidade aumentaram significativamente no grupo experimental comparado com o grupo controle (p < 0.05). Foi evidenciado que após destreinamento de 4 semanas, a adiponectina sérica não se alterou significativamente no grupo experimental e que condicionamento físico benéfico foi gradualmente diminuído. CONCLUSÃO: Nossos resultados sugerem que os efeitos benéficos do exercício físico no condicionamento são temporários. Uma vez que o processo de adaptação é reversível, parece que as concentrações de adiponectina foram inevitavelmente afetadas pelas alterações morfológicas e hormonais que ocorreram durante a puberdade em meninos.

OBJECTIVE: To examine the effect of 12 weeks of (3 days/week) concurrent training and 4 weeks of detraining on serum adiponectin concentrations and physical fitness levels in obese boys without dietary intervention. METHODS: 24 healthy boys, 11-13 years old with body mass index >28 voluntarily participated in the study. They were divided into two groups, experimental (n = 12) and control (n = 12). RESULTS: Adiponectin concentrations after 12 weeks presented significant decline in both experimental and control group compared with the baseline (p < 0.05). VO2 peak, flexibility, strength, endurance of sit-ups and agility significantly increased in the experimental group compared with the control group (p < 0.05). It was shown that after a 4-week detraining, serum adiponectin did not significantly change in the experimental group and that beneficial physical fitness was gradually decreased. CONCLUSION: Our results suggest that the beneficial effects of exercise training on physical fitness are temporary. Since the process of adaptation is reversible, it seems that adiponectin concentrations were inevitably affected by morphological and hormonal changes that occurred during puberty in boys.