Amir Mohtashami; Marziyeh Saghebjoo; Farhad Rahmani-nia
Abstract
Background and Aim: 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 ...
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Background and Aim: 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 (NF-κB), and muscle mass and strength in male athletes. Materials and Methods: 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. Results: 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. Conclusion: 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.
Reza Moqimi; Hamid Rajabi; Sadegh Sadegh Amani-Shalamzari
Abstract
Background and Aim: Resistance training with blood flow restriction stimulates the response and release of anabolic hormones and increases hypertrophy in restricted muscles, however, the effect of this training method on adjacent non-restricted muscles has not been studied well. The aim of this study ...
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Background and Aim: Resistance training with blood flow restriction stimulates the response and release of anabolic hormones and increases hypertrophy in restricted muscles, however, the effect of this training method on adjacent non-restricted muscles has not been studied well. The aim of this study was to evaluate the effect of 4 weeks of resistance training along with blood flow restriction on anatomical cross-sectional area (CSA) of adjacent non-restricted muscles in active young men. Materials and Methods: Sixteen young men aged 25-30 years old were randomly divided into two groups (n=8) high-intensity resistance training (HIRT) and low-intensity resistance training with blood flow restriction (L-BFR). Both groups performed bench press and squat exercises three sessions per week during four weeks. In HIRT group, three sets of 10 repetitions (75%1RM), and in the L-BFR, four sets of 30, 15, 15 and 15 repetitions (30%1RM) was performed during every exercise. For L-BFR group, the restriction pressure was considered as 50% resting atrial occlusion pressure (AOP) at the beginning of the exercises and this pressure gradually was increased to 80% AOP during four weeks. At the beginning and 72 hours after the last training session, the CSA of triceps brachii, pectoralis major, quadriceps and gluteus maximus were calculated by MRI. Data were analyzed by paired sample t-test and analysis of covariance (ANCOVA) test at the significance level of p<0.05. Results: Four weeks of training lead to significant increase in the cross-sectional area of triceps brachii, quadriceps, pectoralis major and gluteus maximus in the HIRT (4%, 7.5%, 10%, 10% respectively) and L-BFR (11%, 12%, 18%, 22% respectively) groups. Conclusion: It seems that the anabolic effects caused by blood flow restriction exercises are not limited locally and can be transferred to the adjacent muscles involved in the exercise that are not directly affected by the blood flow restriction.
Mohsen Mohammadnia Ahmadi; Hamid Rajabi
Abstract
Background and Aim: Nowadays, cold-water immersion (CWI) has been established as a promising means to support recovery in high performance sports after highly intensive training bouts or competitions. There are many studies about effectiveness of acute CWI to support recovery after strenuous exercise, ...
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Background and Aim: Nowadays, cold-water immersion (CWI) has been established as a promising means to support recovery in high performance sports after highly intensive training bouts or competitions. There are many studies about effectiveness of acute CWI to support recovery after strenuous exercise, but the overall results seem to be conflicting. However, adaptational aspect has been widely neglected. Therefore, we analyzed the effects of immersion in cold and moderate water after resistance training on the some adaptations of strength training. Materials and Methods: In all, 32 male Sprague-Dawley rats (8-weeks) were assigned randomly into 4 equal groups including control (208.50±22.50 g), resistance training (208.87±26.70 g), resistance training + moderate water immersion (208.37±16.30 g.) and resistance training + cold water immersion (218.75±33.20 g) groups. The resistance training consisted of climbing (5 reps/3 sets) a ladder (120 cm) carrying load (equal to a percent of body weight) suspended from the tail. At last set (during 6 minute), rats in immersion water groups, immersed within container consisted water with 27˚C and 14˚C respectively. This process repeated 3 times a day during 8 weeks. At the first and last session, ladder climbing strength maximal was measured. Immediately after euthanasia (24 h after final training session), the flexor hallucis longus (FHL) and soleus muscles and subcutaneous-inguinal fat tissue was exposed and weighed. The data was analyzed with the one-way ANOWA method and significance level considered if pResults: Results showed that subcutaneous-inguinal fat (p=0.01), FHL and soleus weight (p=0.01) and maximal strength of ladder climbing (p=0.001) were significantly different in all studied group; so the best improvement was obvious at the resistance + moderate water immersion group. Conclusion: It is concluded that immersion in moderate water have a better impact on the strength training adaptations in rats.
