The present study aimed to investigate the potential effect of different aerobic fitness levels on substrate oxidation in trained taekwondo athletes. 57 male athletes (age 21.10±7.79 years; VO2max 50.67±6.67 ml/kg/min) with regular weekly taekwondo training and training experience of at least three years completed a graded exercise test to exhaustion on a treadmill. Maximal fat oxidation (MFO), the exercise intensity related to MFO (Fatmax), and carbohydrate (CHO) oxidation rate were measured using indirect calorimetry methods. The athletes then were divided into a low (<50 ml/kg/min, n=18) and high (>50 ml/kg/min, n=39) VO2max group. The average MFO was higher in the high VO2max group than in the low VO2max group (0.46±0.19 vs 0.28±0.11 g/min; P<0.001). Although Fatmax tended toward higher values in the high VO2max group, no difference was observed between the groups (49.15±15.22 vs 42.42±12.37% of VO2max; P=0.18). It was also shown that the high VO2max group had a lower CHO oxidation rate and a higher fat oxidation rate at given exercise intensities. In conclusion, it seems that MFO and substrate oxidation rates in taekwondo athletes can be influenced by aerobic fitness level such that the athletes with higher VO2max appeared to use more fat as a fuel source for energy supply during a given exercise.

Objective: Few studies have been conducted on variations of the central nervous system of diabetic patients and much fewer investigations done on the cerebellum of diabetes patients. The current research aims to investigate the effect of endurance training on neurotrophic factors affecting the cerebellum in the diabetic rat. Materials and Methods: This study is experimental.Twenty Wistar rat were randomly allocated in four groups including: (1) control (n=5), (2) diabetic exercise (n=5), (3) healthy-control (n=5), (4) and exercise-healthy (n=5). Diabetes were induced by intraperitoneal Streptozotocin injection. The endurance exercise training was performed at moderate intensity for six weeks. Expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) genes were measured using the Real-Time PCR method in the cerebellum of the rat. Two-way ANOVA test was used for comparing the means of expression of genes between groups. All statistical analyses were done using SPSS 22 software. Results: A significant increase was observed in the expression of NGF (from 1.03±0.11 to 1.61±0.24; P-value≤ 0.05) and BDNF (from 1.59±0.06 to 3.24±0.46; P-value≤ 0.05) genes in male rats with experimental diabetes and healthy subjects after six weeks endurance training. Conclusion: Endurance training may be helpful for diabetic patients by increasing the neurotrophic factors and thereby preventing diabetes-related neural complications.

Identifying the anthropometric characters of adolescent elite players may be useful in developing the recognition of volleyball talents and key physical abilities needed to perform at a high level. The purpose of this study was to describe anthropometric characteristics, including height, weight, body mass index (BMI), spike height, and block height in elite volleyball youth players participating in the 2017 FIVB Volleyball Girls' U18 World Championship. Also, comparisons of these parameters were evaluated based on individual game position (libero, setter, middle blocker, outside hitter, opposite), team continent, and team rank. The variables studied in this study were extracted from the list of players registered on the website of the International Volleyball Federation (FIVB) and included 240 players of 20 teams. The results of one-way ANOVA showed that players in the G1 group (rank 1 to 4) had higher height, weight, spike height, and block height than other groups (rank 5 to 20). Also, the middle blockers had the tallest height (185.9 cm), weight (71.4 kg), spike height (294.5 cm) and block height (282.7 cm). This study presents anthropometric data that show different levels of success for elite girls' volleyball players in the 2017 championship. This information should serve as a reference for average body height, weight, BMI, spike height, and block height for identifying athletic talents for various positions in volleyball.

Background: Proliferation of adipose tissue increases leptin secretion and decreases adiponectin concentration. Exercise is an intervention to control and reverse this process. Therefore, the present study aimed to determine the effect of 8-week high-intensity interval training on leptin, adiponectin, and the ratio of leptin to adiponectin in overweight adolescent boys. Materials and Methods: The present quasi-experimental study was conducted on overweight adolescent boys (13-18 years old, mean body mass index 27.05±1.4 kg/m2). A total of 30 participants volunteered who were divided into three groups of 10 people including short-term (9 sessions of 30-second training with 150-second rest), long-term (4 sessions of 150-second training with 240-second rest), and control group. The training groups performed high-intensity running sprints 3 times per week for 8 weeks. Data were analyzed using two-way repeated-measures ANOVA (3 groups×2 measurement times) and Bonferroni test. Results: Performed high-intensity interval training failed to affect leptin, weight, and body mass index but increased adiponectin and decreased the ratio of leptin to adiponectin (P = 0.042) and fat percentage. No difference was observed between the two types of interval training in changing the level of leptin, adiponectin, fat percentage, and body mass index. Conclusion: High-intensity interval training increases metabolic benefits in overweight adolescents by increasing adiponectin and subsequently decreasing the leptin/adiponectin ratio. Low exercise, no calorie restriction, and other factors affecting puberty may influence the research results.