نشریه پژوهش در علوم زیستی و فعالیت بدنی
پیاپی 5 (پاییز و زمستان 1395)

The core stability muscles play a crucial role both in terms of the optimal performance of athletic skills and in terms of prevention of lower-limp injuries.  Considering the shortage of information about the effects of FIFA's 11+ referees' program on the strength of the core stability muscles, the authors of the present study have made an effort to investigate  the effects of FIFA's 11+ warm-up program for referees on the isometric strength of the core stability muscles of  male Iranian football referees and assistant referees.

To this end, 52 football referees and assistant referees (average age: 27.59±3.70 years for referees and 27.54±3.85 years for assistant referees) who volunteered for the study, were randomly assigned to the either of the experimental or control groups. The experimental group participated in the referees' 11+ program for 17 weeks while the control group used conventional trainings for warming-up during the half season. A digital handheld dynamometer was used both in pretest and posttest stages in order to measure the isometric strength of the core stability muscles. Data analysis was performed through the statistical test of variance analysis.

Results indicated that the posttest isometric strength scores of the core stability muscles of referees assigned to the experimental and control group differed statistically significant in terms of the extensor (referee: F=7.92, P=0.010 - assistant referee: F=4.39, P=0.048); flexor and rotator (referee: F=4.64, P=0.042 - assistant referee: F=8.69, P=0.007) and; the stabilizer muscles of the lateral trunk (referee: F=6.61, P=0.001 - assistant referee: F=8.52, P=0.008). In addition the former and latter groups had significant differences in terms of the overall isometric strength of the core stability muscles (F=31.34, P=0.001 - assistant referee: F=43.50, P=0.001).

According to the findings of the present study, in comparison to the conventional warm-up training, the FIFA's 11+ referees' comprehensive warm-up program can significantly improve the strength of the core stability muscles of referees and assistant referees. Therefore referees and assistant referees are recommended to use the mentioned training program instead of conventional trainings in order to maintain optimal core stability during arbitration in addition to subsequent reduce of probability of injuries.

Talent identification reduces stint to achieve better sports performances by elite athletes. The purpose of this study was the determination and prioritizationof anthropometric, biomechanical and functional characteristics of the elite boys for talent identification and predicting the performance in 100m Backstroke swimming.

The research method is semi-experimental, which is applied based on the object and aim, and it is descriptive according to the method and strategy. The subjects were 30 elite young swimmers, which had won top rank in their provinces and came to the national championships, then they had completed the individual questionnaire and satisfaction questionnaire.The anthropometric, biomechanical and functional parameters were measured by Rydkov questionnaires. Data were analyzed using mean±SD and friedman tests and using SPSS software version 22.

The most important anthropometric parameters were hand length (13.00 cm), forearm length (23.50 cm) and foot length (18.20 cm); the most important biomechanical parameters were elbow hyperextension (3.93 degree), ankle plantar flexion (6.97 degree) and trunk hyperextension (40.87 degree); and the most important functional parameters were action and reaction velocity (20.74 cm), flexibility (26.99 cm) and high jump (29.30 cm) in 100m Backstroke swimming of the elite 11-12 year-old boys.

The results of this study for talent identification and predicting the performance of the elite 11-12 year-old boys in 100m Backstroke swimming, can be considered by authorities, practitioners and coaches.

Present study was aimed to investigate the effect of two active recovery methods in and out water on cardiac stress indices in young female swimmers.

Sixteen young female swimmers were randomly divided into two active recovery groups of the inside and outside water. The swimming protocol and recoveries includes six bouts of 50 m sprint swimming with 120 s rest interval. The data was processed by using SPSS version 22 and Independent and dependent t-test.

Recovery inside the water led to insignificant increase in Double Product and systolic blood pressure (P=0.556and P=0.064 respectively) and significant increase in oxygen pulse (P=0.033). Also, insignificant and significant decrease in maximal heart rate and diastolic blood pressure were observed (P=0.188 and P=0.026 respectively). Outside water recovery led to insignificant and significant decrease in Double Product and maximal heart rate (P=0.980 and P=0.012 respectively). Also, insignificant increase in Oxygen Pulse and systolic and diastolic blood pressure (P=0.154, P=0.408 and P=0.109 respectively).were observed There was no significant difference between the effects of these two recovery methods on any of the indices (P≥0.05).

According to our results, two active recovery methods, inside and outside water after high-intensity interval swimming training, somewhat moderates the cardiac stress indices. But there is no difference between the effects of these two recovery methods on cardiac stress indices.

Fatigue is one of the most important factors affecting the balance in athletes. The purpose of this study was to determine the effect of functional fatigue on static and dynamic balance on female futsal players.

In this semi experimental study, 22 female futsal students with the mean and standard deviation of age 20 ± 1.8 (y), weight 54 ± 2.40 (kg), and height 161.5 ± 5.73 (cm) were selected as the study samples using convenient sampling technique. Functional futsal fatigue was maked with Bangsbo modified semi futsal fatigue protocol. Static and dynamic balance were measured with foot scan set and fatigue with Borg scale before and immediately after of doing protocol. Data was analyzed with dependent T test and significance level of (P=0/05).

Fatigue rate (P=0/000 & ES=1/54),static balance fluctuation rate of pressure center in axes of anterior- posterior (P=0/007 & ES=0/59) and lateral- medial (P=0/014 & ES=0/68) and dynamic balance fluctuation rate of pressure center in axes of anterior- posterior (P=0/000 & ES=0/042) and lateral- medial (P=0/047 & ES= 0/016) were significantly different from pretest.

The results of present research showed functional fatigue increases the fluctuation of pressure center and consequently reduce the balance. This means that at the end of the futsal game, the chance is more likely to be injured.

PAP is a method used to increase nerve-muscular activity after a rigorous exercise that leads to boost the contraction force of muscle after a non- automatic manimum contraction. The study aimed to investigate the intense effect of PAPs with different nest period on the performance and muscle soreness of male taekwondo athletes.

27 athlete athletes 18 to 28 years old range- were selected in the basis of fat percentage, physical and skill performances and classified in there homogenous group; control group, IRM=70%, 90%. the athlete of every group warmed up for 15-20 minutes. Then experimental groups did half-squats there times. In first stage the athlete did squats with two minute rest intervals, height jumping, performance (Ap-Doloya-Chagi), and muscle soreness were measured after 24 hours.

There were significant difference between groups in height jumping and skill performance. Both PAPs increased athlete’s performance (p < .05). There was not any significant difference in athletes’ muscle soreness.

According to finidings of this study, coupling squat jump is recommended to taekwondo athlete due to its effectivenss in increasing their performance. That helps them to improve their power and skill through this method.

Surface instability is a common addition to traditional rehabilitation and strength exercises with the aim of increasing muscle activity. The aim of the current study is to determine if performing push up exercise variations on an unstable surface (Swiss ball and TRX) influences EMG amplitude of the shoulder gridle muscles when compared with a stable surface.  

A convenience sample of 10 subjects performed 3 repetitions for each exercise. Surface electromyograms were recorded from the triceps, pectoralis major, anterior deltoid and serratus anterior while performing push up exercises with the feet or hands placed on bench, TRX and swiss ball.  

TRX and Swiss ball push-ups resulted in greater activation in the pectoralis major and anterior deltoid than those performed on the bench (p≤0.05). The triceps and serratus anterior muscles showed increases in muscle activity when respectively the hands and feet were on the unstable surface (p≤0.05).  

The results of this study indicate that using unstable surfaces will increase the intensity of exercise. The greatest challenge for pectoralis major and anterior deltoid muscles is suggested push up exercises when the hands placed swiss ball And also for triceps and serratus anterior muscles, respectively, from unstable surfaces in the hands and feet.

The brain derived neurotrophic factor (BDNF) and Lipid profile factors have a wide range of biological are influenced by inactive. Therefore, aim of this study was investigating the changed Lipid profile and BDNF following 8 week of combined athletic activity in inactive men.

Twenty-four inactive male randomly divided into two groups: training (n=12) and control group (n=12). The subjects of the training group performed various sports exercises for eight weeks. Blood samplins were taken before and after the study to measure triglyceride, and LDL and HDL and BDNF level. Idependent T-teste was used to examine the difference between groups and paired-samples T test for inter-group variation and Pearson correlation coefficient for relationship between variables. The significance level of (p < 0.05) was considerd.

Serum levels of Triglyceride had a significant decrease comparing with the control group after 8 weeks of exercise (P < 0.044). There was also a meaningful decrease in LDL serum values after this period (P < 0.045). On the other hand, after 8 weeks of exercise, HDL had a meaningful increase compared to the control group (P < 0.005). Also BDNF after 8 weeks of exercise, showed meaningful increase compared to the control group (P < 0.001).

Probably combined training activity can lead to improvement of lipid profile and increasing BDNF in inactive people by decreasing threatening factors and improves cognitive.

Loss of balance and falling down is the sixth leading cause of death in elderly people. Accordingly, exercises that promote postural control are so important for this population. The purpose of present study was investigation of functional balance training on the static and dynamic balance in healthy elderly men.

For this purpose 40 men aged 65-80 years were selected conveniently. All of participants carried out TUG and Sharp and Romberg tests as pre and post tests in order to measure dynamic and static balance orderly. The experimental group participated in an intervention of functional exercises for ten weeks, 3 sessions each week.

The results showed that there is a significant difference between the average modified Sharpend Rumbberg test with open eyes in the functional exercise and control group (f (1.38) =19.06 .p=0.001) Also there was a significant significant difference between the moderated mean of Sharpend rumbberg test with closed eyes (f (1.38=169-22 .p=0.001) and lifting and walking test functional exercise and control group (f(1.38)=115-36. p=0.001)                

According to principle of specificity of exercise, since the functional exercises are similar to real circumstances of daily life, so these kinds of training can help the postural control of healthy elderly men.

Today, due to the massive propaganda that energy drink manufacturers have made in order to increase athletes' performance, this type of beverage has expanded among athletes at various levels. The purpose of this study was to evaluate the effect of energy drinks on blood glucose, fatigue index, heart rate and liver enzymes (AST, ALP) during a basketball match.

11 male basketball players (average age 22.44 ± 2.40 years, mean height 180.22 ± 4.05 cm, weight 70.22 ± 4.17 kg) were selected during two sessions (one session of energy drinking And another session of the placebo) at the time of 10 minutes before the competition (6 ml / kg body weight), and then at 10, 20, 30 and 40 minutes after the start of the competition (2 ml / kg body weight), Consumed energy drinks. 5 cc of blood were collected before consuming energy drinks and immediately after the completion of the competition to assess blood glucose levels, the index Fatigue, heart rate, and liver enzymes (AST, ALP) were collected and analyzed statistically. For data analysis, a Kolmogorov-Smirnov test was used to determine the normality of the data and the measured varibles were compared in the pre and post stages by independent t-test A significant level of (p <0.05) was considered.

The findings of this study showed a significant decrease in fatigue index, AST and ALP levels in the energy drink recipient group before and after the competition. However, the information obtained from heart rate and blood glucose levels in subjects was not significant in spite of relative changes. * Significant level of p

The results of this study showed that ergogenic compounds in energy drinks, by delaying the accumulation of ALP and AST in the blood, increased the time to reach fatigue and improve athlete's performance, but there was no significant effect on blood glucose and heart rate in subjects. It is recommended to use energy drinks prior to the start of the competition or in the final stages of the activity to improve the performance of athletes.