Hamed Esmaeili; Mehrdad Anbarian
Abstract
Background and Aim: Running-induced fatigue is associated with alterations in running mechanics. Mechanisms ofthese alterations are not well known. The aim of this study was to determine the effects of running-induced fatigue onsome of lower limb muscles activity during stance phase of running. Materials ...
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Background and Aim: Running-induced fatigue is associated with alterations in running mechanics. Mechanisms ofthese alterations are not well known. The aim of this study was to determine the effects of running-induced fatigue onsome of lower limb muscles activity during stance phase of running. Materials and Methods: Twenty male runnersparticipated in this study. Subjects along a 14m runway ran 6 times before and after the fatigue protocol. Surfaceelectromyographic activity of Tibilalis anterior (Ta), Medial gastrocnemius (Mg), Lateral gastrocnemius (Lg), Soleus(Sol), Vastus lateralis (Vl) and Biceps femoris (Bf) was recorded before and after the fatigue protocol. Percentage ofmuscular activity, co-contraction index and time to peak muscle activity was calculated during stance phase of running.Data was analyzes using paired t-test at significant level of pabsorption phase, Mg (p=0.02) and Bf (p=0.02) activity, and Vl-Bf (p=0.02), Vl-Lg (p=0.001) and Ta-Mg (p=0.01) co-contraction index decreased after fatigue. In propulsion phase, after fatigue, Ta (p=0.001) activity decreased while activity of Mg muscle (p=0.01) was increased. In this phase Ta-Mg (p=0.0001) and Ta-Sol (p=0.005) co-contraction index decreased after fatigue. In pre-activation phase, fatigue increased Ta (p=0.01) and Bf (p=0.0001) activity. Also, fatigue increased time to peak activity of Bf, Gm and Gl muscles (p=0.001). Conclusion: Fatigue can make alterations in running muscular mechanism indicating neural system attempt to reduce injury risk during fatigue. Therefore, in order to prevent running related injuries, we recommend considering percentage of muscular activity timing in novice runners.
Asieh Mirzaaghajani; Hasan Alikhani; Zahra Hojjati; Mohammadali Gharaat
Abstract
Background and Aim: Since the use of interval training could be affected on aerobic performance, the effects of twotypes of continuous and high intensity interval training on aerobic performance in elite rowers were discussed in thepresent study. Materials and Methods: Among sixty elite male rowers that ...
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Background and Aim: Since the use of interval training could be affected on aerobic performance, the effects of twotypes of continuous and high intensity interval training on aerobic performance in elite rowers were discussed in thepresent study. Materials and Methods: Among sixty elite male rowers that participated in inter-country rowingchampionship, eighteen rowers (who selected as Iran national team members) divided randomly into two groups(continuous training and high intensity interval training). Rowing ergometer (Concept 2 model) and gas analyzer device was used, moreover simultaneously physiological factors measured (VO2max and VVo2max with gas analayzer, Tmax with chronometer). The training protocol in continuous group was consisted of 10 km rowing for three weeks (10 sessions per week) with 70-75% of maximum heart rate. High intensity interval (HIIT) group was done 8 sessions of continuous training per week plus 2 sessions of HIIT (including 6 sets X 1 minute ergo performance X 100% VVo2max). To analyze data, t-test was used to compare the differences within and between groups and the level of significance was set as prespectively) and VVo2max (p=0.02, p=0.004 respectively) in post-test. Moreover, the Tmax was increased in the HIIT group significantly (p=0.001). The results of independent t-test in VO2max (p= 0.52), VVo2max (p=0.42) and Tmax (p=0.14) did not show any significant differences. Conclusion: These findings showed although both types of training schedules improved VO2max and VVo2max; however improvement rate after HIIT training was no significantly higher. With accounting of only 20 percent of high intensity interval training sessions, a definitive statement about comparing the two types of exercises, further study needs.
Samaneh Ebrahimpour; Khadijeh Irandoust
Abstract
Background and Aim: Ghrelin is a hormone that has the main role in energy regulation and obesity, so it would beimportant to have strategies for monitoring this substrate. The purpose of this study was to investigate the effect ofomega 3 supplement and aerobic exercises on plasma levels of ghrelin and ...
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Background and Aim: Ghrelin is a hormone that has the main role in energy regulation and obesity, so it would beimportant to have strategies for monitoring this substrate. The purpose of this study was to investigate the effect ofomega 3 supplement and aerobic exercises on plasma levels of ghrelin and appetite in obese women. Materials andMethods: Among all healthy Lahijan women, 60 non-athlete obese healthy subjects (35-45 yr.) were chosen voluntarily and randomly divided into four groups (aerobic, supplement +aerobic, supplement, control). Training + supplements group and training group were exerted 12-week aerobic program. As well as training + supplements and supplements groups also consumed omega-3 daily 2 capsules. The exercise groups jogged 4 d/wk. at 55% to 65% of maximal reserve heart rate. Plasma ghrelin, appetite, and anthropometrical characteristics were assessed 48 hours following and prior to training and at the end of luteal phase. Dependent t-test and One-Way ANOVA and Tukey tests were used to analyze the data. Results: the results indicated that ghrelin and appetite increased significantly in aerobic and supplement+aerobic groups (p=0.0001), while didn’t change in supplement and control groups. Conclusion: it was concluded that omega-3 supplement has no significant effect on ghrelin and appetite levels whereas aerobic exercise may increase ghrelin and appetite in obese women. This result probably proves this hypothesis that aerobic exercises lead to increased levels of ghrelin and increased calorie intake due to elevated energy expenditure.
Bahloul Ghorbanian; Aghaali Ghasemnian
Abstract
Background & Aim: Tomor necrosis factor alpha (TNF-α; as a pro-inflammatory cytokine) and interlokin-10 (IL-10; asan anti-inflammatory cytokine) have an important role in the development and the prevention of systemic inflammation and incidence of obesity-induced diseases such as CAD, ...
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Background & Aim: Tomor necrosis factor alpha (TNF-α; as a pro-inflammatory cytokine) and interlokin-10 (IL-10; asan anti-inflammatory cytokine) have an important role in the development and the prevention of systemic inflammation and incidence of obesity-induced diseases such as CAD, respectively. The aim of this study was to investigate the effectsof 8-week interval endurance combined training (IECT) on plasma TNF-α, IL-10, insulin resistance, and lipid profiles inoverweight and obese boy adolescents. Materials and Methods: In this semi-experimental study, 28 healthy overweightand obese boy adolescents (16.93 ± 1.89 yr., 88.07 ± 9.98 kg. and 28.35 ± 2.55 kg/m²) were volunteered and randomlyassigned into training (n= 13) and control (n= 15) groups. Exercise protocol was IECT (8 WK, 4 d/wk, 70 min/d). Bloodsamples were taken before and after exercise to assess the variables. Serum levels of TNF-α and IL-10 were measuredby sandwich ELISA method. T-test and Pearson correlation coefficient was employed. The criterion of statistical significance was set as p0.05). Moreover, the amounts of insulin resistance, triglyceride, total cholestrol; low density lipoprotein, low density lipoprotein/high density lipoprotein, total cholesterol/high density lipoprotein, body fat percent, body mass index, and waist circumference were significantly decreased and VO2max significantly increased (p<0.05).Conclusion: It seems that a combination of interval endurance training for 8 weeks can be considered to weight controling, reducing blood lipids and improving aerobic fitness, but to create favorable changes in cytokines, such as TNF-α and IL-10 is not sufficient. Probably, it is more useful with more intensity and volume. To achieve more accurate results, more studies are needed in this area.
Hoda Abdi Hamzekolai; Abbas Ali Gaeini; Mohammad Reza Kordi; Valiolah Dabidi Roshan
Abstract
Background and Aim: There are many studies about the acute effects of anabolic androgenic steroids on thecardiovascular system, however, there is little information on its prolonged effects. The purpose of this study was toevaluate the long-term effects of anabolic - androgenic steroids on cardiovascular ...
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Background and Aim: There are many studies about the acute effects of anabolic androgenic steroids on thecardiovascular system, however, there is little information on its prolonged effects. The purpose of this study was toevaluate the long-term effects of anabolic - androgenic steroids on cardiovascular indices in the former bodybuilders.Materials and Methods: Twenty-three male people were divided into 3 groups: former bodybuilders (n=8), youngcurrent anabolic anderogenic steroid (AAS) users bodybuilders (n=8) and control (n=7) groups. Body composition,hemodynamic cardiovascular stress responses such as systolic and diastolic blood pressure, double product, meanarterial pressure and heart rate was evaluated prior and after an exhaustive test on a treadmill. Results: The one wayANOVA showed no significantly changes between former bodybuilders and control groups before and after exercise(p>0.05). But heart rate (p=0.001), diastolic blood pressure (formers-young, p=0.002 and young-control, p=0.01) anddouble product (young-control, p=0.05 and formers-young, p=0.04) were significantly higher in young current usersgroup as compare to other groups. Conclusion: The results of this study confirmed the reversibility of cardiovascularhemodynamic performance after discontinuation of long-term of using of anabolic androgenic steroids, although morestudy is needed to confirm these findings.
Abbas Meamarbashi; Heydar Joodat; Marefat Siahkouhian
Abstract
Background and Aim: Body building sport is probably most dependent to balanced and scientific nutrition. Therefore,the purpose of this study was to design and evaluation of computerized diet programs on the performance andanthropometric parameters in body builders. Materials and Methods: In a semi-experimental ...
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Background and Aim: Body building sport is probably most dependent to balanced and scientific nutrition. Therefore,the purpose of this study was to design and evaluation of computerized diet programs on the performance andanthropometric parameters in body builders. Materials and Methods: In a semi-experimental study, seven malebodybuilder students were selected. One week of their regular diet analyzed by nutritional evaluation and diet therapysoftware for energy and nutrients. Then, one week balanced diet was designed with the software according to bodybuilders’ dietary and exercise requirements (Energy=3000 kcal, 55-65 percent by carbohydrates, 20-25 percent by fat, 18-20 percent by protein). The effectiveness of the diet was evaluated before and after diet therapy by comparison ofweight, body fat percent, circumferences (waist, hip, arm, thigh and wrist), muscular strength, muscle force, and 24 hurine urea and creatinine concentrations. Daily diet consumption analysis was done by the software. Subjects had theirregular training exercise during both periods (three sessions of weight training per week). To evaluate the effectivenessof balanced diet, dependent t-test was implemented and Pearson's regression also was used to find any relationbetween parameters (p<0.05). Results: The results of this research showed significant increase in the chest, arm, andthigh circumferences as well as standing long jump, vertical jump, hand dynamometry, lift dynamometry, one repetitionmaximum leg press, curl up, and pull-up chest press and a significant decrease in the body fat percent and chestcircumference has seen found (p<0.05). Furthermore, a significant and positive correlation was found between chestand arm circumferences (r=0.80) and between chest and thigh circumferences (r=0.87)(p<0.05). Among functionalparameters, hand grip and lift dynamometer (r=0.75), long and vertical jumps (r=0.82) showed positive correlations.Conclusion: With regard to the results of this research it may conclude that a designed balanced diet in term of energyand macronutrients when considered individual and sporting requirements as well as appropriate training needs is ableto improve body composition, anthropometric parameters and athletic performance without necessary for supplementation.
Mahboobe Ajam Zibad; Hossein TaheriChadorneshin; Seyed Hosein Abtahi Eivary
Abstract
Background and Aim: Studies have reported conflicting results regarding the acute effects of exercise on inflammatory, oxidative stress and muscle damage parameters. Therefore, this study aimed to investigate the effect of acute resistance exercise on serum levels of tumor necrosis factor alpha (TNF-α), ...
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Background and Aim: Studies have reported conflicting results regarding the acute effects of exercise on inflammatory, oxidative stress and muscle damage parameters. Therefore, this study aimed to investigate the effect of acute resistance exercise on serum levels of tumor necrosis factor alpha (TNF-α), as a marker of inflammation, malondialdehyde (MDA), as a marker of oxidative stress, and levels of lactate dehydrogenase (LDH) and creatine kinase (CK), as two markers of muscle damage. Materials and Methods: For this purpose, 20 healthy and inactive women (age, 21.55+1.56 year; BMI, 21.68+3.26 kg/m2) were randomly divided into acute resistance exercise and control groups. The subjects performed one bout of acute resistance exercise with 85% of one-repetition maximum (1RM) at 8 stations (bench press, leg press, seated rows, overhead press, seated leg press, arm extension, arm curls and calf raises), each exercise were done for 3 sets. Blood samples were taken before and immediately after exercise. TNF-α and MDA levels were measured using ELISA method by commercial kits. Moreover, LDH and CK were measured by photometric method. Paired sample t-test and independent t-tests were used to analyzed dependent variable within and between groups, respectively (p<0.05). Results: One bout of acute resistance exercise had significant increases (p=0.001) in serum levels of TNF-α and MDA. Also, serum levels of muscle damage parameters, LDH (p=0.03) and CK (p=0.001), showed significantly increases following acute resistance exercise. Conclusion: One bout of intense resistance exercise is associated with oxidative and muscle damage in inactive women, therefore adoption of training and nutritional approaches are essential when implementing with this kind of exercise.
Azam Behrad; Roya Askari; Mohammad Reza Hamedinia
Abstract
Background and Aim: In the present study two types of endurance training as, high intensity interval training andcircuit resistance training on pulmonary function and body composition were studied among some overweightfemales. Materials and Methods: In this research forty-five qualified females volunteered ...
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Background and Aim: In the present study two types of endurance training as, high intensity interval training andcircuit resistance training on pulmonary function and body composition were studied among some overweightfemales. Materials and Methods: In this research forty-five qualified females volunteered and were randomly dividedinto three groups including circuit resistance, high-intensity interval and control groups. Subjects in the training groupwere trained for 8 weeks with 3 time intervals. The resistance group practiced 2 circles, each consisting of 7 stations;each station included 2 sets of 8-15 repetitions, with an intensity of 65-85% 1RM. In the interval group subjects performed training at intensity of 85-95% of maximum heart rate with 8-11 repetitions including 2 minutes running and 2 minutes active resting time between intervals (30-40% HRmax). Before and after the end of the training sessions,spirometry, body composition, muscular strength and endurance and VO2max were taken. Data were analyzed byone-way ANOVA, LSD post hoc and dependent t-test. Results: The results showed no significant difference between study groups concerning forced expiratory volume (FEV1), force vital capacity (FVC), FEV1/FVC, forced expiratory flow 25-75% (FEF25-75%), body weight, body mass index and wait to hip ratio (p< 0.05). Lean body mass significantly increased in the resistance group (p< 0.04) and only resistance training group showed a significant development in FVC compared to baseline values (p< 0.03). Resistance and interval training groups showed a significant decrease in percent body fat (p< 0.008 and poverweight females.
Elnaz Dizaji; Heydar Sadeghi; Raghad Memar
Abstract
Background and Aim: Postural control is very important in most sports, especially karate. It seems that the historyof prolonged karate exercises affect parameters such as the balance in contralateral lower limbs. So, the aim of thisstudy was to compare the postural stability in dominant & non-dominant ...
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Background and Aim: Postural control is very important in most sports, especially karate. It seems that the historyof prolonged karate exercises affect parameters such as the balance in contralateral lower limbs. So, the aim of thisstudy was to compare the postural stability in dominant & non-dominant leg of female kata and kumite national teamwith sensory interference. Materials and Methods: 12 kumite and 8 kata female karate athletes in 2013 national teamparticipated in this study. Medial longitudinal arch of foot were measured using emed platform during barefoot walking.Postural stability was assessed using biodex stability system during unilateral standing with opened-eye and closedeyein stable and unstable surface. Repeated measures analysis of variance was used to compare parameters and thelevel of statistical significance considered if pexamined, there was no significant difference between dominant and non-dominant leg (p>0.05); but when visual’selimination was applied, significant differences have been observed in overall (p=0.02) and mediolateral (p=0.03) stability indices in unstable surface. No difference was found in any of the sensory challenge between two groups (p>0.05). Conclusion: It seems that balance isn't suitable factors for selecting kata or kumite as a talent identification characteristics. because it does not make difference between two groups in higher levels of performance . Also leg’s dominance and resulting unequal use of legs may affect balance that perhaps karate-ka higher balance of non-dominant leg is caused by better proprioception. Finally, perhaps there is a relationship between the negative adaptation of musculo-skeletal system and athletes' repetitive patterns of skills that leads to bridge the gap in understanding, prevention and treatment of this phenomenon.
Akbar Rahimi; Ramin Balouchi; Rasoul Eslami; Mehdi Shahrokhi
Abstract
Background and Aim: Falling is a major health problem among elderly that has significant affect their health and lifequality, but it can be possibly prevented by development of muscle strength. The purpose of this study was to investigatethe relationship between strength of spine extensor muscles with ...
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Background and Aim: Falling is a major health problem among elderly that has significant affect their health and lifequality, but it can be possibly prevented by development of muscle strength. The purpose of this study was to investigatethe relationship between strength of spine extensor muscles with dynamic balance and fear of falling in elderly people.Materials and Methods: 68 elderly men and woman with mean age of 70±5.43 years, height of 157.29±8.59 cm andweight of 70.64±9.63 kg were randomly recruited among volunteers. Dynamometer, biodex stability system and modified MFES questionnaire were used to assess strength of spine extensor muscles, dynamic balance and fear of fallingrespectively. This research was an empirical and causal relationship study, and to elicit the results, Pearson correlationcoefficient was used and significance level was considered if pcorrelation between strength of spine extensor muscles and dynamic balance in anterior-posterior direction (p=0.0001), while no significant correlation was shown between strength of spine extensor muscles and dynamic balance in media-lateral direction (p=0.29). In addition, there was a significant positive correlation between strength of spine extensor muscles and fear of falling (p=0.01). Conclusion: Strength of spine extensor muscles is an effective factor to maintain balance at anterior-posterior direction and fear of falling
