جستجوی مقالات مرتبط با کلیدواژه "training intensity" در نشریات گروه "تربیت بدنی"

Resistance training (RT) plays a major role in developing muscle mass and strength. This study aimed to compare the effect of eight weeks of modified German volume resistance training (MGVRT), high-intensity resistance training (HIRT), and non-linear resistance training (NLRT) on the serum levels of myostatin (Mstn), follistatin (FLS), nuclear factor kappa B (N F-κB), and muscle mass and strength in male athletes.

Forty young men bodybuilders were randomly assigned into equal groups, including MGVRT, HIRT, NLRT, and control. Training protocols were performed for eight weeks (three times a week). Selected biochemical variables, muscle mass, and strength were measured before and 48 hours after the last training session. For statistical analyses the analysis of covariance, repeated-measures analysis of variance, Kruskal-Wallis, and Mann-Whitney U test‏s were and significance level was set as p≤0.05.

The Mstn and FLS protein levels significantly decreased and increased, respectively in all three experimental groups compared with the control group. Moreover, the NF-κB level was significantly lower in the MGVRT and HIRT groups than NLRT and control groups. Furthermore, the arm and thigh circumference and muscular strength in the chest press and squat movements significantly increased in all three experimental groups as compared with the control group where the increase in arm circumference in the MGVRT group was significantly higher than in the HIRT and NLRT groups and as the same the muscular strength in the HIRT group was significantly higher than in the MGVRT and NLRT groups.

All three RT protocols lead to improve biochemical, anthropometric, and functional indices in male athletes, but the MGVRT and HIRT protocols led to more increase in muscular hypertrophy and maximum strength, respectively. However, further studies are needed on the relationship between RT protocols with muscle mass and strength, and the biochemical parameters associated with them.

Several studies have examined the effect of chronic aerobic training on factors associated with non-alcoholic fatty liver disease. The aim of this study was to determine the effect of different intensities of chronic aerobic training (low, medium and high) on alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and gamma glutamine transferase in men and women of different ages. Done in 1400. Databases, ScienceDirect, PubMed, Scopus and Google Scholar were searched along with keywords. A total of 120 non-review articles with appropriate quality of aerobic training were reviewed and 22 articles were meta-analyzed. Accordingly, 1560 people with an average (52 ± 10 years) Fatty liver disease was examined. The effects of the intervention were evaluated using SMD and stochastic effects model. In the results of meta-analysis of aerobic training in general with any intensity significantly reduces the levels of aspartate aminotransferase, alkaline phosphatase and gamma glutamine transferase. Alanine aminotransferase levels decreased more in high-intensity training than in moderate-intensity training (P = 0.01). Aspartate aminotransferase levels decreased more in moderate-intensity training (P = 0.001) than in high-intensity training (P = 0.03). The effect of high-intensity and moderate-intensity training on gamma glutamine transferase levels was not significant (P = 0.2).Keywords: Non-alcoholic fatty liver, Alanine aminotransferase, Aspartate aminotransferase, Aerobic training, training intensity

Soccer preparation requires the use of aerobic and anaerobic energy systems, which can be achieved by the intensity distribution of training. This study aimed to evaluate the effect of 4 weeks of polarizing training on aerobic and anaerobic fitness variables in soccer players. 20 soccer players in Tehran soccer league were divided into polarized (n=10; 52.11 ml/kg/min) and usual soccer training (n=10; 53.31 ml/kg/min) groups based on maximum oxygen consumption. Subjects were evaluated before and after four weeks of polarize (four-session consisting of three sessions of high volume -low-intensity training followed by a high-intensity interval training session) and usual soccer training (Four sessions per week including two sessions of high-intensity interval training, one session of lactate threshold training and one session of low-intensity training) to measure maximal oxygen consumption and soccer-specific, mean and peak power and respiratory exchange ratio. Maximum oxygen consumption, peak power, soccer-specific Maximum oxygen consumption and respiratory exchange ratio were significantly increased after four weeks of polarized and usual soccer training (P<0.05). Also, the polarized training model resulted in a significant increase in maximal oxygen consumption, peak power, and specific soccer maximal oxygen consumption compared to the usual soccer training model (P≤0.01). The results showed that the distribution of training intensity based on the polarized model can be more effective in short term than the usual soccer training in off-season preparations.

Background and The angiogenesis inhibitors and the pro angiogenesis factors are enhanced in diabetic patients; especially those are involved in exercise. The purpose of this study was to compare the effects of endurance training with moderate and high intensities on some angiogenesis factors in renal tissue of diabetic rats. Sixty male rats were divided into 6 groups (n=10 per group): Sedentary control (SC), Sedentary Diabetic (SD), Diabetic Moderate intensity training (DMT), Healthy Moderate intensity training (MT), Diabetic High intensity training (DHT) and Healthy High intensity training (HT). The exercise protocol performed 8 weeks of moderate and high intensity aerobic training, 5 sessions per week and 60 minutes per session. Eight weeks of moderate and high intensity aerobic training significantly reduced blood glucose in diabetic rats, but this decrease was higher in the DMT group. Also, eight weeks of moderate and high intensity aerobic training in both diabetic groups significantly increased VEGF (P = 0.002 and P = 0.000, respectively) compared to the SD, but for VEGFR1 was observed only between DHT compared to SD (P = 0.007). compared to high intensity aerobic training, moderate aerobic training results in a decrease in the levels of glucose and an increase in VEGF.

The aim of this study was to evaluate two different intensity of resistance training with the same volume on the plasma levels of malonyl dialdehyde (MDA), reduced glutathione (GSH) and total antioxidant capacity (TAC) in healthy men. 30 healthy men with aged 20-25 years participated in this study and were randomly divided into three groups of moderate-intensity resistance training (hypertrophy), high intensity resistance training (strength) and the control group. Hypertrophy resistance training (3 sets of 10 repetitions with 70% of one repetition maximum) and strength training (4 sets of 6 reps with 85% of one repetition maximum) for 8 weeks and were administered three times a week. Venous blood samples were obtained from the subjects during fasting and two times, 24 hours before the start of the protocol and 48 hours after the last training session. Repeated measure ANOVA revealed that MDA concentration was significantly reduced in exercise groups compared to control group. In addition, the amount of the reduction in hypertrophy training was more compared with strength training group (P=0.0.4). GSH concentration was significantly increased in exercise groups compared to control group. Hypertrophy training was more increases in GSH levels compared with strength training. TAC levels increased in both groups, but the increase was significantly only in hypertrophy training but was not found a significant difference between the groups. In conclusion may be resistance training could improve antioxidant system (GSH and TAC) and decrease the MDA and it was independent from intensity of training.

Skillful performance in soccer requires not only sound techniques but also quick and accurate decision making. These decisions are usually made in various intensities of practice and performance. The main aim of this study was to investigate the effect of different levels of arousal and training intensity on decision making (speed and accuracy) of expert female soccer players. For this purpose، 16 expert female soccer players (mean age 22. 4±3. 8 yr) with 8 or more years of competitive experience were voluntarily selected from Tehran women''s premier league. Soccer related photographs on a computer monitor were used to evaluate the decision making task; participants had to decide which action they would undertake (shoot، pass، dribble). Three different levels of arousal (low: with no spectators، medium: with silent spectators and high: with cheering spectators) in three different levels of intensity (resting، 40% of HRmax، 80% of HRmax) were designed. To measure the accuracy and speed of decision making، parametric method of MANOVA، 3 (training intensity levels) in 3 (arousal levels)، was used. To totally compare the groups، one-way analysis of variance، ANOVA with repeated measures and Tukey post hoc test were used at α=95%. The results showed no significant difference in the speed of decision making among different arousal levels (P>0. 05) while a significant difference was observed in the accuracy of decision making among different arousal levels (P˂0. 05). The speed of decision making improved in the low and medium arousal levels through an increase in training intensity while no significant difference was observed in the speed of decision making in high arousal level among different intensity levels (P>0. 05). Furthermore، the accuracy of decision making showed no significant difference in low and high arousal levels among different intensity levels (P>0. 05). The accuracy of decision making improved in low arousal level through an increase in training intensity. These finding showed that training intensity and arousal separately influenced each decision making component.