Exercise Science
Diyar Mohammed Ali Albajalan; Naser Rostamzadeh; Daruush sheikholeslamivatani
Abstract
Background and Purpose: Resistance training (RT) is an effective program for creating hormonal, functional and structural adaptations, so that manipulation of its variables induces different adaptations. Change in the secretion rate and serum level of hormones due to resistance activity is the main factor ...
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Background and Purpose: Resistance training (RT) is an effective program for creating hormonal, functional and structural adaptations, so that manipulation of its variables induces different adaptations. Change in the secretion rate and serum level of hormones due to resistance activity is the main factor in protein synthesis and hypertrophy of skeletal muscles, so the purpose of this study was to investigate hypertrophic and hormonal responses to a session of resistance training with two different protocols in men’s sprint runner.Material and Methods: 45 men volunteers (age: 21± 1.7 year, weight: 67.5± 4.35 kg and BMI: 22 ± 1.03 kg/m2) were randomly divided into three groups of 15 people (high-load training, low-load training and control). The training protocol includes seven movements (chest press with barbell, leg extension, biceps barbell, standing shoulder press with barbell, seated leg machine, lat pull down and triceps machine), three sets with 70% 1-RM to failure for training group with high load, seven movements (chest press with barbell, leg extension, biceps barbell, standing shoulder press with barbell, Seated leg machine, lat pull down and triceps machine), three sets with 30% 1-RM to failure for training group with low load, and no activity for control group. Thickness of biceps and vastus lateralis and serum levels of cortisol, IGF-1, testosterone hormones and testosterone/cortisol (T/C) ratio were measured at two stages (pre-test and 30 minute after the RT). The Shapiro–Wilk and the Levine tests were performed to confirm the normality of data distribution and the homogeneity of variances, respectively.Results: The result of paired-sample t test showed serum concentration of testosterone (P=0.005), IGF-1 (P=0.004), cortisol (P=0.020), T/C (P<0.001), thickness of biceps (P=0.001) and thickness of vastus lateralis (P=0.001) were increased only in RT group with high load compared to the pre-test. Also, the results of ANOVA and Bonferroni’s post hoc test showed the mean of serum concentration of testosterone, IGF-1, cortisol, T/C, thickness of biceps and vastus lateralis in high-load training group was significantly higher than the low-load training (P ≤ 0.05) and control (P ≤ 0.05) groups in the post-test.Conclusion: Although one session of resistance training with an intensity of 30% of 1RM did not cause a significant change in the serum level of hormones and hypertrophy, it seems that hypertrophy produced after a 70% of 1-RM acute resistance training protocol (and with repetition to failure) appears to be due to hormonal changes due to metabolic stress.
hersh nouri; dariush shaikholeslami vatani; Naser Rostamzadeh
Abstract
Purpose: The aim of the present study was to investigate the effects of short-term vitamin D supplementation on the pulmonary function and physical fitness factors in adolescent wrestlers. Methods: 36 wrestlers (age: 16.18 ± 0.81 years, height: 171.5 ± 5.7 cm, weight64.2±.36 kg, ...
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Purpose: The aim of the present study was to investigate the effects of short-term vitamin D supplementation on the pulmonary function and physical fitness factors in adolescent wrestlers. Methods: 36 wrestlers (age: 16.18 ± 0.81 years, height: 171.5 ± 5.7 cm, weight64.2±.36 kg, BMI: 21.6 ± 1.75kg/m2, Ft mass: 8.9±1.82%) participated in this study. The subjects in the experimental group received 2000 IU of vitamin D daily and the control group received the same amount of placebo for 14 days, during which time they also performed wrestling training (5 sessions per week). To investigate the research variables, serum 25(OH)D levels, pulmonary function by spirometry test and physical fitness indices were measured twice, before and after supplementation periods. The data were analyzed using the analysis of covariance. Results: Results showed that vitamin D levels (23%) and FVC indices (20%), FEV1 (17%), MVV (12%), FEV1 / FVC (11%), FEF25 / 75 (13%) were higher significantly in vitamin D compare with placebo group (P>0.05). But there was no significant difference between PEF, FEF25, FEF75, FEF50 and physical fitness factors (shuttle run, 50m sprint, sit-ups, pull-ups, push-ups and Sargent jump) in the experimental group compared to the placebo group (P>0.05). Conclusion: The present findings of this study indicated that short-term vitamin D supplementation may improve pulmonary function in adolescent wrestlers by affecting respiratory muscle strength and decreasing airway resistance but did not affect their physical fitness.
Dariush Sheikholeslami Vatani; Fariba Fallahi; Roonak Tabei
Volume 11, Issue 1 , November 2018, , Pages 45-58
Abstract
Purpose: Exercise can lead to various hematological changes and it may be effects on some blood variables.The purpose of present study was to investigate the effects of resistance training with different order onhematological changes (include HGB, HCT, RBC, WBC, MCV, MCH, MCHC, RDW, PLT and MPV) in overweightwomen ...
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Purpose: Exercise can lead to various hematological changes and it may be effects on some blood variables.The purpose of present study was to investigate the effects of resistance training with different order onhematological changes (include HGB, HCT, RBC, WBC, MCV, MCH, MCHC, RDW, PLT and MPV) in overweightwomen (BMI= 25-30 Kg/m2).Methods: Thirty-one overweight students (Weight: 71.91 ± 8.28 kg and Height: 160 ± 0.05 cm) wereobjectively selected and randomly divided into three groups: the experimental group 1 (perform exercisesfrom large to small muscles, n= 10), the experimental group 2 (perform exercises from small to large muscles,n= 11) and the control group (without any training program, n= 10). Resistance training consists of 6 weeks(3 sessions per week). The hematological variables were measured in resting conditions before experimentand again after completion of the training period.Results: Findings using by one-way ANOVA revealed there were no significant differences in any of thehematologic variables levels between three groups.Conclusion: In general, results showed that medium-term resistance training program and so changing thesequence of performance of resistance exercise – none of them – do not have any effect on hematologicresponses.
