فصلنامه فیزیولوژی ورزشی
پیاپی 18 (تابستان 1392)

One of the principles of training is specificity of training. Especially during competition season، because of probability of interruption in rhythms of movements and skills in sport activities using of resistance training programs with normal device in clubs can be not useful for improvement of the speed and the power of appropriate muscles. We are paying attention on how to apply resistance training program in sport skills especially in throwing skills like shot put in track and field and punch technique in martial arts without any decrease in quality of our technique. For instance، normal resistance training such as training with weight devices، because of incorrect time sequence of muscle contractions can affect to wrong technique. Then considering type of muscle contraction، rhythms، speed، rang of motion in training programs especially in competition season is a good way to improve performance and decrease of time for preparation program. Advantages of this new device are summarized as follow: 1- It follows movement pattern it has a relation with throwing skills، 2-It can use of specific muscles with specific contraction in related with throwing skills، 3- Releasing of weight from hand after doing performance like shot put or other throwing tools، 4- Increase of load on muscles during force producing phase. For determine of validity we selected 15 elementary Karatekas. We divided them in experimental (n= 8) and control (n= 7) groups. Every group began karate training for 6 weeks with 3 session for every week. Every session included warm-up (20 min)، technique learning (20 min)، conditioning (15 min) and 10 min cool-down. Conditioning training was 5 sets of 10 repetitions work with machine for experimental group and push up with same volume and intensity (Borg scale) for control group. Pre and post test data collected from power of upper limbs (distance of throwing of 3 kg shot put). Both groups had a significance increase after 6 weeks training program (Exp: p=0. 001، Con: 0. 001) but experimental group had significance increase than control group (p=0. 034). This device is a simple brake machine and sinuses motion of one lever that can produce variable forces and change the liner motion of hand to angular motion in brake system. We hope that using of this machine will be useful for shot put athletics to increase their records and decrease of period of preparation time. As this device is a first approach in this area، thus more research could be conducted in the future.

High-level athletes necessarily do exercise training at different times-of-day (rather morning & afternoon). The main purpose of this study was to determine the diurnal variation effect on responses of mucosal immune indices inclusive saliva flow rate (SFR)، alpha-amylase (sAA)، salivary immunoglobulin A concentration (sIgA) and sIgA secretion rate (sIgASR) to a training set of intermittent swimming (including: 12×100m front crawl at mean 92% maximum heart rate) in the elite male swimmers. For this reason، in a counterbalanced design، 9 male swimmers of swim national team (age: 17. 9±3. 1 years) participated in two exercise trails (7:30h: AMEX and 17:00h: PMEX) separated by at last 5 days. Unstimulated whole saliva samples were obtained before and after exercise، and again 1، 3 and 24h later. Mean heart rate، weight lose and mood state was the same at the both trials (p>0. 05)، but temperature was higher in PMEX (p<0. 05). Basis levels of SFR، sIgASR and sAA activity unlike with sIgA were higher in PMEX than AMEX (p<0. 05). sIgA was increased immediately after exercise (p<0. 001) despite of no change in SFR by drinking water adlibitum، that was caused by increased sIgASR (p<0. 005); These changes are associated with increase in sAA activity. Also، the responses of sIgASR and sAA unlike with SFR and sIgA concentration were affected by diurnal variation (p<0. 001). It appears that these changes properly are due to diurnal variation in adrenergic function. Nevertheless، a 1h to 3h rest was enough to return the changes to basis status.

The aim of this study was to compare the effects of high-intensity interval training (HIT) and moderate-intensity continuous training (MCT) on maximal oxygen uptake (VO2max)، ventilatory threshold (VT)، respiratory compensation point (RCP)، 3000-m running time (3000-m RT)، peak (PPO) and mean power output (MPO). Therefore، twenty two collegiate soccer players participated in this study، voluntary. They were randomly divided into HIT group (12) and MCT group (12). Each training session involved 10 min warm-up، HIT program (6 to 10 × 30 s all-out sprints with 4 min recovery) or MCT (45 min running at 70% VO2max)، and 5 min cool down performed 3 per week for 8 consecutive weeks. After training intervention، VO2max (7. 6% vs. 8. 9%)، VT (4. 5% vs. 3. 9%)، and RCP (4. 2% vs. 3. 8%) increased، and 3000-m RT decreased (-4. 4% vs. -4. 2%) significantly in HIT and MCT groups، respectively (p ≤ 0. 05). There was no difference between the two groups for these variables (p > 0. 05). Also، there was only an improvement for PPO (8. 3%) and MPO (10. 9%) in HIT group (p ≤ 0. 001). It seems that HIT program with present training protocol، result in similar adaptations for cardiorespiratory fitness and endurance performance، compare with MCT program. Also، HIT program increases anaerobic capacity، simultaneously.

Delayed-onset muscle soreness (DOMS) usually occurs after unaccustomed eccentric exercise and reduces exercise performance. Many treatment methods proposed to prevent and alleviate DOMS in sport but no effective method has been found. This study aimed to study the preventive effects of oral supplementation with saffron on the biochemical and functional symptoms of DOMS after a one-session eccentric exercise. Twenty-four non-active and healthy male university students (Age: 19. 6±1. 14 yr) randomly divided it to experimental (n=12) and control (n=12) groups. A leg press apparatus equipped with two force isometric sensors connected to a computerized dynamometer to determine the maximum isometric force. Ten days before and 24، 48 and 72 hours after muscle soreness protocol، the maximum isometric and isotonic forces، plasma creatine kinase (CK)، and lactate dehydrogenase (LDH) were measured. Muscle soreness protocol was employed with a load equal to %80 of maximum isotonic force in four sessions and each one with twenty repetitions and 3 min rest in between. Changes in the measures in each group over time were analyzed separately using repeated-measures ANOVA followed by Bonferroni test. Independent-Samples t test was used for comparison between two groups at each time measurement. This study shows daily supplementation with 300 mg saffron during ten days، significantly decreased the CK and LDH concentrations (p<0. 001). There was no decline in maximum isometric and isotonic forces after eccentric exercise in experimental group، but observed significant decline in the maximum isometric and isotonic forces in the control group (p<0. 001). Results obtained from the current novel research indicating a strong preventive effect of ten days supplementation with saffron on the delayed-onset muscle soreness.

The purpose of this study is to comparison of bone mineral density (BMD)، bone mineral content (BMC) and muscular strength between elite males karateca practitioners (kata & kumite styles) in southern Khorasan. Participants were 12 kumite practitioners (age=22. 6±2. 23 yr. & BMI=22. 43±1. 95 kg/m2)، 12 kata practitioners (age=21. 5±1. 15 yr. & BMI=22. 38±3. 14 kg/m2) and 12 healthy untrained men (age=22. 9±1. 60 yr. & BMI= 21. 85±2. 89 kg/m2). Athletic groups had minimally 5 years experience in karate sport and they have healthy state and normal diet. The BMD and BMC in thigh bone (neck، trochanteric and proximal) and forearm area (two third of distal of ulna & radius، and carpal bones) measured By DXA method. Grip and back strength of participants were evaluated using Yagami dynamometer. It is applied the one-way ANOVA and Tukey tests for extraction of results and significant differences was considered if p<0. 05. Result showed that in kumite practitioners، BMD (p=0. 04 & p=0. 000 respectively) of forearm area، grip strength (p=0. 02 & p=0. 000 respectively) and back strength (p=0. 000 & p=0. 000 respectively) were significantly higher than kata practitioners and untrained group. In addition، the BMD & BMC in thigh bone (p=0. 000 & p=0. 03 respectively)، grip strength (p=0. 000) and back strength (p=0. 000) of the kata practitioners were significantly higher than untrained group. Present study indicated that karate training improved efficiently bone condition and muscular strength; but in comparison of two styles of this sport، the kumite style have naturally more mechanical impacts، and thereby can induce more beneficial effects on the bone condition and muscular strength of participants.

The purpose of the present study is to examine the effect of one session of long term training on the concentration of Leptin and lipoprotein lipase in the tissues of male rats. for the purpose of this study، 16 Wistar male rats (25 months) with a weight average of 387±31. 09 gr were selected randomly from male rats were purchased from Pasteur Institute of Iran and Based on similar weights، they were divided in two groups: experimental group (n=8) and control group (n=8). The experimental group performed a training session on the rodents'' treadmill with a speed of 18 m/min on a 0˚ slope for two hours. Immediately after training and after about five hours of fasting، 4 rats from each group، i. e. the experimental group and control group، (totally 8 rats) were alternatively anesthetized and two hours later، 8 other rats were anesthetized، too. A blood and tissue sampling (from muscle and fat tissue) was conducted. Using special kits via ELISA method، the Leptin content of the tissue and serum insulin were measured. Lipoprotein lipase activity and serum glucose was also measured by special kits and enzymatic colorimetric method. The results from the independent t test showed that، immediately after training، there was no significant change in Leptin variables of the muscle tissue (F=0. 63، P=0. 07)، Leptin of the adipose tissue (F=2. 39، P=0. 30)، lipoprotein lipase in the muscle tissue (F=0. 63 and P=0. 59) while lipoprotein lipase of the adipose tissue (F=2. 06، P=0. 02) indicated a significant increase. Two hours after training، Leptin variables of muscle tissue (F=0. 022، P=0. 21) and adipose tissue Leptin (F=0. 112، P=0. 07) did not show a significant change but the activity of the lipoprotein lipase in the muscle tissue (F=0. 03، P=0. 03) and adipose tissue (F=2. 99، P=0. 001) proved a significant increase. This study showed that a long-term training session with increased LPL activity results in increased hydrolysis of the triglycerides. Therefore، it can increase the capability of muscle fibers for absorbing and oxidizing plasma fatty acids and subsequently has a positive effect on the metabolism of the fats

Resistin is an adipocyte-derived hormone، plays a key role in regulating energy homeostasis and metabolism. The aim of this study was the effects of regular aerobic training on resistin gene expression in trained young Female. 20 females were randomly divided into control and experimental group. The experimental group performed aerobic training for 8 weeks، 4 sessions in every week، and with the intensity of 70-80 % of maximum heart rate. The control group did not do any train in this period. Resistin expression was investigated after separating the lymphocytes by centrifuge and using semi-quantitative RT-PCR. Statistical analysis was performed by independent and paired t-tests. Results of this study showed that there were significant different between the average of BMI and the fat percentage before and after the 8 weeks in experimental group (p=0/00). There were significant difference between the average of resistin gene expression related to the post-test in control and experimental group (p=0/036، t (18) = -2/268). Overall، eight weeks regular aerobic exercise through reduction of weight، body fat and elevation of resistin gene expression cause reduction of the possibility of cardiovascular diseases and increase of strenghth anti-oxidation defences of the body، in young female.

The purpose of the present study was to determine the effects of two types of resistance exercise training (isotonic and isometric) on bilateral transfer effect (cross education). Subjects (n=40، untrained for least 6 months) were randomly assigned to a control group or one of the two groups of resistance training that trained their knee extensor muscles unilaterally. Training was 3 times/wk for 6 wk with three sets of 6-8 repetition (2 minutes rest interval) maximum at 80% one repetition maximum (1RM) for isotonic group and for isometric group، resistance training program was 30 isometric extension maximal voluntary contraction (MVC) for 2-4 second with 15 second rest between each contraction. Control subjects attended sessions but did not exercise. Knee extensor strength was measured with two tests (1RM and MVC) before and after training. Integrated electromyography (IEMG) also was measured. Unilateral isotonic and isometric resistance training significantly (p≤0. 05) increased 1RM، MVC and IEMG in the trained and contra lateral untrained limbs، but no significant changes occurred in any variables in the control group. Results of IEMG changes، only showed significant differences between isotonic and control groups. In the view of the resistance exercise intensity and rate of cross education in each groups، it seems isotonic resistance exercise training may be useful than isometric type in rehabilitation program.

Chemerin is a novel adipokine that play an important role in regulating lipid metabolism and adipogenesis. There is limited information available regarding the effect of exercise training on serum chemerin concentrations. The purpose of this study was to investigate the effect of Aerobic training on serum chemerin levels and lipids of plamsa in overweight women. 20 Overweight subjects (age: 35. 64±5. 55 yr، weight: 69. 62±9. 30 kg، body mass index: 27. 93±3 kg/m2) were randomly assigned to aerobic training (n= 12) and control (n= 8) groups. Aerobic training was performed 4 times weekly for 8 weeks. Resting levels of plasma chemerin and lipid profiles were measured before and after the intervention. After 8 week aerobic training، levels of chemerin plasma were significantly decreased in aerobic trained group when compared with their control groups (p<0. 05). Concurrently، levels of HDL-c were significantly decreased (p<0. 05) whereas، levels of cholesterol، TG and LDL-c، showed no significant changes (p> 0. 05). No significant correlations between chemerin levels and weight loss were observed in subjects with overweight women. The present study demonstrated، 8 weeks aerobic training، reduced serum chemerin concentrations in overweight women. Whereas، aerobic training exercise programmes affected the lipid profile response of obese subjects differently. However further research is warranted in order to unravel the molecular mechanism for the range of responses and the role of serum chemerin.