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Background and Purpose: Beta-alanine supplement, which is a precursor of carnosine, may improve performance by providing a buffering effect. The purpose of this study was to investigate the effect of betaalanine supplementation and regular Taekwondo training on anaerobic, aerobic, and endurance activity substrate metabolism in female Taekwondo athletes. Materials and Methods: Twenty-four female professional taekwondo practitioners (age, 18.0±2.5 years), from Tehran province volunteered to participate in this research. Based on the body composition and training history, the subjects were divided into two groups (n=12) of supplement and placebo. The pre-tests consisted of the an aerobic specific test (Progressive Specific Taekwondo Test, PSTT) including repeated strikes of Bandal-Tchagui to exhaustion time during a maximum duration of 15 minutes and a taekwondo anaerobic test (Frequency Speed of Kick Te, FSKT) including 5 sets of 10-second high-speed Bandal- Tchagui kicks with maximum strength. Furthermore, the substrate metabolism of the endurance activity was measured by a gas analyzer, and the VCO2, VO2, VO2peak, HR, and HRpeak were measured. During and immediately after the test, the level of perception of fatigue was evaluated. Moreover, blood lactate levels were measured using a lactometer after the anaerobic and aerobic tests. After 28 days of receiving the supplement or placebo (5g/day) at the designated day times, the pre-test measurements were repeated. Repeated measures of ANOVA with between-group factor and Bonferroni post-hoc tests were used to compare the data. Results: There was no significant difference between the two supplement and placebo groups for anaerobic capacity, aerobic capacity, and substrate metabolism (p<0.05). Although, both groups (supplement and placebo) showed significant improvements in the time to exhaustion and the number of steps to exhaustion in the post-test compared to the pre-test, these improvements were significantly higher in the supplement group compared to the placebo (p<0.05). Conclusion: During the research period, beta-alanine supplementation had only an effect on some performance indicators and probably more pronounced effects on the performance of elite athletes would be seen in the long term. However, this little gain can be important in professional athletes, and more studies are needed in this field for a concrete conclusion. [ABSTRACT FROM AUTHOR]

Objective: Diabetes is characterized by a comprehensive increase in apoptosis, mitochondrial dysfunction, and inflammation in skeletal muscle. Impaired mitochondrial function in skeletal muscle leads to an increase in Cytochrome C and Caspase-9, and muscle performance is reduced consequently. Exercise training through decreasing inflammatory factors and increasing anti-inflammatory elements prevents apoptosis pathways. Materials and Methods: Forty male Wistar rats (150±10 g, 8 weeks age) were assigned to 4 groups: control (C), diabetes (D), high-intensity interval training (HIIT), and diabetes high-intensity interval training (DHIIT). Diabetes was induced with intraperitoneal injections of Streptozotocin (STZ) and blood sugar higher than 250 was considered diabetic. The effects of six weeks of HIIT on soleus muscles, Cytochrome C, and Caspase-9 gene expression, as well as evaluation of tumor necrosis factor-alpha (TNF-a) in serum were evaluated using Real-Time PCR and ELISA techniques respectively. Results: In comparison with C group Diabetes has significantly increased the Cytochrome C (P= 0.001) and caspase-9 (P= 0.003). However, HIIT training in diabetic rats significantly decreased the Cytochrome C (P= 0.001) and caspase-9 (P= 0.008) in comparison of D group. Also, TNFa (P= 0.01) increased in the D group in comparison with C and DHIIT group (P= 0.001). In comparison between DHIIT groups in HIIT groups, has a significant increase in time to exhaustion post test than pretest (P= 0.001). Conclusion: It seems that HIIT training decreases intrinsic factors of the apoptosis pathway by decreasing inflammatory factors which leads to significant improvement in skeletal muscle function and overall health in diabetic rats. [ABSTRACT FROM AUTHOR]

Background: Aerobic exercises induce adaptations that improve physiological function. However, aerobic exercises, oxidative reproduction may lead to injury and other health issues such as adverse cardiac effects. The aim of this study is to evaluate the effect of aerobic exercises on protein expression change in the heart left ventricle to determine the advantages and disadvantages related to this mode of exercise. Methods: Male Wistar rats were randomized into two groups; trained (T) and control (C). Animals from T group were trained for 8 weeks, and then 2D LC-MS/MS iTRAQ method was used for extracting and analyzing the left ventricular proteins. Certain proteins that were highlighted in the special process were selected for further analysis via protein-protein interaction network (PPI) method. The identified proteins were enriched via gene ontology (GO) to find biological terms. Results: We identify five overexpressed antioxidant proteins in T group compared with C group including extracellular superoxide dismutase [Cu-Zn], Frataxin, protein kinase C delta type, STE20/SPS1-related proline-alanine-rich protein kinase, and amyloid-beta A4 protein. Conclusions: Findings indicate that catalase and insulin are two exercise-related proteins. However, they were not included in the significant differentially expressed proteins. Finally it was found that enhancement of antioxidative activity is a direct effect of aerobic exercises. [ABSTRACT FROM AUTHOR]

Background and Objectives: In recent years, the use of cold water immersion (CWI) following heavy training sessions has become a common habit among athletes aiming to reduce soreness, but there aren't strong scientific rational behind this belief. Hspb1 gene, which expressing heat shock protein 25 has an important role in recovery and adaptation to exercise. The aim of this study is to investigate the Hspb1 gene expression following post eccentric exercise cooling, during primary and late recovery. Materials and Methods: Fourthy male Wistar rats (n=40; W= 300±10gr) were divided into two groups of exercise (Ex group) and exercise with cold water immersed group (Ex+CWI). Each group furture subdivided in to three subgroups based on three time-courses (0, 3, and 48 h after exercise). Exercise consists of 90 min interval downhill running (18"5 min, 2 min rest between intervals, 20m/min, and 17° decline). Post exercise cooling consists of 10 min of cold water immersion in 10°C water. Hspb1mRNA level was measured in soleus muscle using Real-Time PCR. The results were studied by statistical methods. Results: Gene expression of Hspb1 increased 3 hour's after exercise in both groups, but the difference between two groups was not significant in this time course. However Hspb1mRNAexpression in Ex+CWI group 48 hr after-exercise was significantly less than Ex group (P=0.016). Conclusion: This study indicates that cooling after eccentric contraction. Exercise may suppress Hspb1 gene expression during late recovery period and interfere with protective role of this gene during the recovery of skeletal muscle after exercise. [ABSTRACT FROM AUTHOR]

Background: Alpha-actinins are located in the skeletal muscle Z-line and form actin-actin cross-links. It belongs to a highly conserved family of actin-binding proteins- the spectrin superfamily, which also contains the spectrins and dystrophin. Mammalian skeletal muscle has two isoforms: alpha-actinins-2 and alpha-actinins-3. However, the response of alpha-actinins to exercise training is little understood. This study examined the effects of 8 weeks of resistance training on muscle mass, ACTN3 (alpha-actinins-3) gene expression levels and fiber type composition in the flexor hallucis longus (FHL) muscle. Methods: Forty five female Sprague-Dawley rats (Initial body mass: 169.25±9gr age: 3 month) were obtained and assigned to a control (C; n=18) or exercise training (T; n=22) and pilot (P; n=5) groups. The resistance training consisted of climbing a ladder carrying a load suspended from the tail and the weight increased progressively. Real-time PCR and Immunohistochemistry techniques were used to measure gene expression levels and myosin heavy chain (MyHC) composition, respectively. Results: Following 8 weeks of training, we observed significant increase in absolute muscle mass in FHL (P=0.01). Results showed that no significant difference was found in ACTN3 gene expression levels between training and control groups (P=0.852 respectively). Also, Pearson coefficient didn't indicated any significant relationships in gene expression and Fiber type IIX in response to resistance training in FHL (r=0.12). Conclusion: However, resistance training effects on sarcomeric proteins development, these results showed no effect of resistance training on alpha-actinins-3 levels. Although alpha-actinins-3 has an important function to produce and progress of force in sarcomere, but didn't changed significantly in response to resistance training. [ABSTRACT FROM AUTHOR]

The minimal running velocity at which maximal oxygen uptake (VO2max) is elicited during an incremental test to exhaustion has been used to prescribe training for competitive middle- and long-distance runners. The purpose of this study was to determine the relationship between velocity at lactate turnpoint (vLTP) and vVO2max in long-distance runners. For this purpose 11 highly trained endurance runners were selected randomly from the national team. The average age, height and mass of the subjects were 24.36±1.1 years, 1.73±0.02 m and 63.25±21 kg respectively. The first test was used to determine vVO2max and VO2max (a continuous run to exhaustion with the start velocity at 10 km/h and the velocity increased 1 km/h per minute). The second test was used to determine vLTP (start velocity was 10 km/h and velocity increased 1 km/h for 4 min to reach lactate concentration over 5 mmol/l). The average VO2max and vVO2max of subjects were 58.54±2.8 ml/kg/min and 19±0.29 km/h respectively. Pearson’s correlation coefficient and SPSS 12 software were used for analysing data. There was a positive moderate correlation between vLTP and vVO2max ( p=0.037, r=0.63). This study may indicate that, the more the athlete is capable of delaying the accumulation of his/her lactate, and the higher the velocity at which the accumulation takes place, the higher vVO2max he/she can have. On the other hand, coaches can design training programmes at vVO2max intensity to promote a higher vLTP. [ABSTRACT FROM AUTHOR]