Showing 14 results for Power
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Volume 9, Issue 1 (3-2011)
Abstract
In order to compare the acute effects of OR and Megabasic (two energy drinks)
by a placebo, 24 volunteer male athletes (age: 24.3±2.03 yrs, height
173.56±7.02cm and weight 75.43±3.07kg) participated in two consecutive
RAST tests by 40 min rest interval in between within 3 randomly divided groups.
There were six times blood sampling (before and also 2 and 4 min after than
both tests) in order to analyze blood lactate and PH levels (Gas analyzer) and
also the anaerobic indices (Peak, mean and mean power) was calculated. The
data corresponding to each group’s blood factors was compared by ANOVA for
repeated measurements (post hoc: Bonferoni), their changes between two
consecutive RAST tests was compared by ANOVA (post hoc: LSD) and
anaerobic power data for each group was compared using pair sample t test at
0.05 significance level. Results: Significant changes were observed in blood
lactate and PH levels during repeated measurements in both RAST tests at all
groups (p<0.05). There were also significant differences in the amount of the
changes in between the measurements between groups (p<0.05). Additionally,
Peak and min power only significantly increased in second RAST test rather
than first one and mean power also significantly decreased in both energy drink
groups between the first and second RAST tests (p<0.05). Conclusions:
Consumption of the OR can affect anaerobic power during short term repeated
interval activities. However, there are evident differences in between multiple
brands of energy drinks with regard to the amount of the modifications in the
changes at both blood lactate and PH levels, in spite of this fact that there is
any consensus in this field because of the lack of comprehensive researches.
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Volume 9, Issue 2 (10-2011)
Abstract
This study is aimed to evaluate the effect of 4 weeks swimming training with
chest wall restriction on aerobic power, cardio-respiratory functions and
swimming performance of elite female swimmers. 24 elite female swimmers
volunteered to participate in this study and were randomly divide into two
groups: Control (swimming training without chest wall restriction) and
experimental group (swimming training with chest wall restriction). Both groups
were in a monthly swimming program (they trained 3 times a week for a total of
4 weeks). They swam almost 3.5 to 4 km/d with 70 – 85% of HRmax. Aerobic
power, pulmonary parameters, time to exhaustion and swimming performance
were measured. To analyze data, student t test was used. The results showed
that Time to exhaustion increased in group training with chest wall restrictor
(P=0/012). T-20 test results showed improvements in experimental group. No
significant difference was observed in VO2max, MVV, FVC, and FEV1/FVC in
two groups. Also there was no significant difference between the groups.
Therefore, the results showed that using chest elastic band in order to impose
more stress on respiratory muscles during exercise leads to some adaptations
in these muscles and it is associated with some improvements in exercise
performance.
Rasol Rezaei, , , ,
Volume 11, Issue 6 (10-2013)
Abstract
Abstract
The aim of this study was designing a specific upper body anaerobic power test for wrestlers and determining validity, reliability and objectivity of the designed test. In order to assess the anaerobic power of wrestlers on the basis of upper body Wingate test, Twenty two wrestlers (age=23/40±3/20 year, height=173/13±6/97 cm, weight=74/55±3/88 kg) of Tehran wrestling team (most of them were Asian champion) were participated in this study. Mean, maximum and minimum of anaerobic power and fatigue indices assessed by both tests. In order to analysis the correlation between power indices and physiological indices (blood lactate and heart rate), Pearson correlation has been used, and the differences between blood lactate after 2 min in both tests assessed. The result indicated that there was significant correlation between maximum (p=0/001 r=0/739), mean (p=0/001 r=0/670) and minimum (p=0/01 r=0/650) of power and fatigue indices (p=0/003 r=0/610) obtained by designed test and Wingate test. The result showed that there was significant correlation between heart rate immediately after doing both tests (p=0/001, r=0/705) and also the result show that there was not significant correlation between blood lactate after 2 min. of doing both tests (p=0/07 r=0/353). Statistical analyses also showed no difference between the blood lactate after 2 min of doing both tests. Analyzing the validity of designed test, revealed that there was significant correlation between max (p=0/000 r=0/840), mean (p=0/000 r=0/861) and minimum (p=0/000 r=0/830) power and fatigue indices (p=0/000 r=772) after performing twice of designed test. In analysis objectively of the designed test, the result revealed that there was significant correlation between max (p=0/000 r=0/832), mean (p=0/000 r=0/858) and minimum (p=0/000 r=0/805) power and fatigue indices (p=0/000 r=0/832) which was done by two different tester. It can be concluded that in respect to Wingate upper body test, the designed test in this study is valid and reliable test to measure the anaerobic power of wrestlers.
Jalil Ataei, Dr Mohammad Reza Dehkhoda, Dr Hamid Rajabi, Dr Naeima Khajavi, Sara Zarea Karizak,
Volume 12, Issue 8 (10-2014)
Abstract
The purpose of this study was to compare effect of 4 weeks of strength training in two ways of accommodation and constant resistant methods on maximum strength and power of trained athletes. Sixteen Wushu athletes and wrestlers chosen from Tehran’s clubs with a mean age of 20.50 ±2.00years, height 174.34 ± 6.53cm, weight 70.22 ± 10.50 Kg, and body fat percent, 12.87 ±. 4. 23 participated in this study. After the initial testing of the variables of maximum strength (1RM), upper body power (medicine ball to throw, cm) lower body power (vertical jump, watt) Body fat percent (Skin Fold three point), limb circumference (cm) and Weight (kg), divided in two equal groups. Each group has done resistance strength training program for 4 weeks, three sessions per week, with 85% of their 1RM, with three sets and 5 repetitions with Squat and bench press exercises. But in case of accommodation group, 20% of their 1RM was used by chain through the full range of motion. At the end of the training, re-test of dependent variables were performed under similar conditions. Covariance analysis was used to compare the progressof power and strength between the two groups. This study showed that weight (p=0.391), limb circumferences (P=143), fat (P=0.413), the upper body power (P=0.267), lower body power (P=0.252) and the maximum upper body strength (P=0. 803) there was no significant difference between groups, but in case of maximum strength of lower body (P=0.04) there was significant difference between the two groups. In analyzing the results, although most variables did not show significant difference, but the effects sizeanalyzing of groups showed that in upper body power (ES=0.62), lower body power (ES= 0.64),upper body strength (ES=0.13)and lower body strength (ES=1.84), the results were in favor of accommodation group. This difference in the maximal strength in accommodation group were (62.15% in the upper body, 68.38% lower body) and in constant strength group (86.14% in the upper body, 84.21% in the lower body) respectively. Also the effect size of power for accommodation group were (97.6% upper body, 61.6% lower body) and in constant group (16.4% upper body, 67.4% lower body), respectively. This study showed that in order to increase maximal strength and power, accommodation training method is more effective than traditional constant training.
Abbas Keyhanian, Dr Khosro Ebrahim, Dr Hamid Rajabi, Dr Seyed Mohammad Marandi,
Volume 13, Issue 9 (4-2015)
Abstract
The aim of this study was to Compare the effect of resistance training with active and passive rest on aerobic
and anaerobic fitness in soccer players. For this purpose 16 players of Foolad Mobarakeh Sepahan club,
accidentally were divided into rest and active group (Height 177.78±6.68 cm, Weight 64.88±7.97 kg, age
18.22±0.83 years ,and percent fat 20.47±1.8) and rest passive group(Height 178.57±6.99 cm, Weight 64±
6.6kg, age 18±0.81 years ,and percent fat 20.05±1.7). The tests were performed in this order: maximal oxygen
consumption, maximal strength, Tmax, muscular endurance, Hoff and RAST test in the pre and post test. The
exercises were done for 8 weeks and twice week with 10 exercises of 30 to 50 percent of maximal strength
with this difference that the active rest group performed 3 sets of 20 repetitions exercise in 30 seconds that rest
interval between 30 seconds was completed with 2 sets of 10 repetitions exercise in 30 second. The passive
group performed 4 sets of 20 repetitions exercise in 30 seconds that rest interval between 30 seconds was
completed with 3 sets passive rest. After determining the normality by Kolmogorov-Smirnov test and
homogenous variance test, independent and dependent t-tests with a significant level of α ≥ 0.05 were used.
The results indicate that after the training period, a significant difference was found in all variables exceptfatigue index in active rest group. But in passive rest group there were a significant difference in variables AT,
vVo2max, Tmax, performance of Hoff test, bench press muscular endurance and leg press strength from pre
test to post test. The results between groups indicated that there was a significant difference between two
groups in Vo2max, Tmax, AT, vVo2max, leg press muscular endurance, and mean power in benefits of active
rest group. Finally, the results showed that the resistance training with active rest causes improvements in
aerobic and anaerobic fitness of soccer players in comparison to resistance training with passive.
Mr Mahmood Khodabakhshi, Dr Ahmad Ebrahimi Atri, Dr Seyed Ali Akbar Hashemi Javaheri, Mr Hosein Ashoori, Mr Naser Farokh Roo, Mr Vahi Khodabandeh Loo,
Volume 13, Issue 10 (10-2015)
Abstract
One of the most important success factors in most athletic competitions, receiving aerobic power (speed,
agility and jumping) high. Basketball is a great combination of short and long term activities that depend on
aerobic fitness. Anaerobic fitness of many players during the match determines tactical the performance.
The purpose of the present study to investigate the effects of strength exercises on anaerobic power and
some the variables related Traband it. The subjects consisted of 30 basketball players Young, randomly into
two equal groups of 15 subjects (experimental and control) were randomly assigned to 6 weeks and 3
sessions the Exercises were done in a week. To analyze the data, independent samples T-test and paired
sample T-test used at a significance level p ≤ 0/05. Later for six weeks of exercises, significant differences
between the records obtained from the anaerobic power the variables (speed, agility, vertical jump) were
observed between the two groups. The present study showed that the strength exercises with the variables
Traband improve anaerobic power in young basketball players and And according to the results of seem to
exercises Traband useful method for improving performance of the anaerobic the athletes.
Mohamad Hadi Ghasemi, Mohamad Fashi,
Volume 16, Issue 15 (9-2018)
Abstract
The aim of present study was comparison of advanced physical fitness profile between Olympic soccer team members of Iran according to playing position. 29 Invited soccer players to the 17th national Olympic soccer team of Iran dispatched to 17th Asian Olympics Games, Incheon 2014 )mean age of 20.39± 2.01 yrs(, divided into five group of goalkeepers, defenders, midfield players, wingers and attackers according to playing position participated in the study. Body composition parameters (including body mass index, body fat percentage), isokinetic force (peak torque, agonist/antagonist ratio, work fatigue, total work of extension and flexion), aerobic power by analysis of respiratory gases and anaerobic power and fatigue index by Wingate test were packaged for data collection. Descriptive statistics (i.e., mean ± standard deviation) and inferential statistics (i.e., one way ANOVA with Hopkins post hoc after subtracting data of pre- post) used for analysis data. While it was unbelievable the findings did not show any significant difference between five groups of present study. It seems that Olympic soccer team players of Iran has not prepared in a conditioning principle and based on playing position for participate in 17th Asian games. Moreover it supposed that national players spent most of the preparation periods & specific based conditioning workouts on their clubs, hence due to the short time of conditioning in the national camps trainings, players have not dispatched to the games with favorable preparation.
Mansour Eslami, Mohsen Nazari,
Volume 16, Issue 15 (9-2018)
Abstract
All sustained physical activities subject the body to various levels of fatigue. This is especially evident when running, which is one of the most popular forms of exercise and may be described as a reduction in maximum force production and power output . the purpose of this study was to investigate the effect of running in an exerted state on knee muscles power absorption and work during the stance phase of running. Sixteen healthy physical education male students with an average age 22 and SD 2.27 years and height 177 and SD 5.47 cm and mass 72.6 and SD 8.4 kg participated in this study voluntary. Kinetic and kinematic data recorded by using of video camera and force plate. The negative and positive power and work of muscles operating on knee has calculated using inverse dynamic equations in MATLAB2010 Software. Paired sample T test was done to statistical analysis in SPSS 2010 software (p≤0.05). The results of this study indicated that negative peak power and work significantly decreased 33.78% and 22.6% respectively. Although the positive peak power significantly decreased (p≤0.05), positive work didn’t change significantly (p=0.644). The results of this research indicated that the absorbing function of the muscles is decreased following fatigue and may be led to increase the injury risk of running.
Majid Jalili, Farzad Nazem, Akbar Sazvar,
Volume 16, Issue 16 (12-2018)
Abstract
Aerobic power (VO2max) is an important indicator of the health and physical fitness. Executive problems in direct VO2max measurement has led to developing sub-maximal aerobic power prediction equations. The purpose of present study was to develop native aerobic power prediction equation based on 6-Minute Walk Test (6MWT) and body composition indices in children. In 192 healthy children (8 to 12 years) VO2max was objectively measured by Bruce treadmill protocol with gas analysis. The 6MWT was performed according to ATS guidelines. Also, anthropometric measurements were measured according to standard methods. Multiple regression analysis was used to design aerobic power (ml/kg/min) prediction equation. Accuracy of native VO2max prediction equation was assessed by Pearson correlation and Bland-Altman approach between measured and predicted VO2max. Significant correlation was observed between direct VO2max and independent variables (r=0.25-0.734). Aerobic power of the boys could be predicted by weight and 6MWT according to the following equation: VO2max(ml/kg/min)= 5.359 + (0.067 × 6MWD m) – (0.286 × Weight kg) (r2=0.743, SEE=2.74 ml/kg/min, p≤0.001). Strong correlation was observed between measured and predicted VO2max (r=0.861, P≤0.001). In addition, Bland and Altman plots demonstrated a high degree of consistency between measured and predicted VO2max. Exercise and fitness coaches by utilization of native aerobic prediction equation based on the 6MWT and weight could be able to assess the aerobic power of the boys and to evaluation of the effects of exercise training on cardio-respiratory fitness.
H Rajabi, P Motamedi, D Zabihi,
Volume 18, Issue 19 (7-2020)
Abstract
The purpos of this study was to determine the effect of twelve session of high intensity cycle training with blood flow restriction on aerobic and anaerobic performance of active student men. To this purpose, 24 valentear active students men from physical eduction faculty of kharazmi university aged 19-23 years old, students (mean ± SD weight: 67.89±6 kg, height: 173.92±5.41cm, and BMI: 22.7±6.84kg/m2) divided into three groups of blood flow restriction (BFR) (n=8), none blood flow restriction(NBFR) (n=8) and control group (n=8). The exercise consisted of cycling at 80% Wmax for ten 1-min bouts, with a 2-min rest between bouts with 50% Wmax (total time, 30 min). Before and after implementation of the training protocol, Astrand Test to check the aerobic performance and Wingate test to check anaerobic performance was conducted. To data analysis, the independent t-test, analysis of variance test and post hoc test (LSD) was used. Results indicated that two weeks of high intensity cycling with and without blood flow restriction does have a significant impact on VO2max(p=0.000) and Wmax(p=0.000) and time to exhaustion (p=0.001). The results indicate a further increase in aerobic performance components, in exercise with blood flow restriction training group compared to the unrestricted blood flow training group. The results olso indicated that tow weeks of cycle training with occlusion does not have a significant impact on peak anaerobic power(p=0.064), average anaerobic power(p=0.058) and minimum anaerobic power(p=0.826). In general, the results showed a partial restriction of blood during cycling interval training have affect on aerobic adaptations, but does not affect on anaerobic adaptations.
Dr Shirin Yazdani, Prof Nader Farahpour,
Volume 19, Issue 21 (9-2021)
Abstract
Background and Objective: although it is documented that the spine and hip alignments alter in scoliosis subjects, but the effect of these changes on the lower extremities’ biomechanics have not been well understood yet. So, the aim of this study was to compare hip, knee and ankle joint’s power generation and absorption during gait in patients with adolescent idiopathic scoliosis (AIS) and healthy controls. Methods: Using motion analysis system with 4 Vicon-460 cameras and two Kistler force plates, the kinematics and kinetics of gait was assessed in twenty girls with AIS and 20 matched healthy controls, then the power of the right and left hip, knee and ankle joints in sagittal plane was calculated. Data was analyzed using ANOVA statistical method with significance level of α<0.05. Results: Results showed that in scoliosis group, the peak power absorption of the right knee was significantly 12.5% smaller than that in control group (p=0.01). But, peak power generation and absorption of the hip and ankle joints in both right and left limbs were not statistically differed between the two groups (p>0.05). Conclusion: scoliosis is associated with the smaller power absorption of the knee joint at convex side. This might be linked with unilateral alterations of the joints' moment, joint forces, and the related muscle activity which might impose asymmetrical force to the hip and cause curve progression.
Dr Heydar Sadeghi, Mohsen Ali Darchini, Hossein Nabavi Nik,
Volume 19, Issue 22 (12-2021)
Abstract
Core stability (CS) is a popular term that has evolved into a fundamental concept the much rehabilitation, performance training and preventative programs. The purpose of this study is considering the relationship between CS power and endurance with performance of adolescence athletes. 12 male swimmers participated in the study. McGill Protocol, the core stability power, MBESTT and 30/60 sit-up test were used to measure the CS endurance and power, respectively. Participants' performance was measured as the specific (stroke-index, 100m crawl stroke) and general performance (standing-broad-jump (SBJ), vertical Jump, 9.1 m sprint, shuttle-run, flexibility and seated medicine-ball toss tests). The Pearson correlation coefficient was used to determine the relationship between the CS power and endurance with general and specific athletes' performance. The results showed only significance relationship between trunk flexion with SBJ and seated medicine-ball toss, and flexibility and total CS power score with flexibility. Also, negative significance relationship found between left lateral flexion with shuttle-run test and trunk flexion with stroke-index. The findings of this study showed a weak correlation between CS with specific and general athletes' performance. Based on our findings, there is no necessity for focusing on swimming training programs.
Ms Sepideh Samavati Sharif, Phd Abbas Ferjad Pezeshk, Phd Mohammad Yousefi,
Volume 19, Issue 22 (12-2021)
Abstract
This study aimed to determine the role of strength, expulsive power and range of motion of lower limb muscle on the fencing performance of elite florists. In this study, eight elite fencers’ participated. Kinetic variables measured using force plate and kinematic variable measured using motion analysis system. The squat jump test used to measure the compulsive power of the lower extremity muscles of the fencers. The Drop-jump test used to measure the lower strength of the muscles of the lower extremity muscles. Descriptive statistics (mean and standard deviation) used to describe the data and Pearson correlation coefficient used for determine the relationship between data (P≤0.05). The results of this study showed there is a significant relationship between squat jump power and mechanical energy and drop jump height with lunge speed and also between ankle range of motion with peak force and impulse in the anterior direction (P<0.05). Given the results of this study, coaches should have a special attention on the strength and explosive power of plantar flexor muscles.
Mr Mojtaba Sadeghi, Dr Hamid Rajabi, Dr Farzad Nazem,
Volume 21, Issue 25 (9-2023)
Abstract
The purpose of this study was determine the effect of upper body plyometric training on anaerobic power and record of 25 meters front crawl performance in 10 years old swimmer boys. 16 swimmer boys chosen voluntarily (The mean age was 9.9 ± 0.7 years ، weight 45.9 ±9 kg , Height 149.8 ± 5 cm، BMI is 19.20 ± 3 Kg / m 2 ) And Subjects divided into two groups of training (n=8) and control(n=8).Before and after the implementation of the protocol investigate test 25 meters front crawl performance at the distance 10, 20 and 25 metrs and the number of hand strocke to check the performance of the swimming also anaerobic hand wingiting test function was evaluated. To analyze data, used the covariance test.The results showed six weeks upper body plyometric training Performance Indicators an hands Front crawl Including Peak power increased Significantly (18%) but the average power increase (7%) was not significant (p>0.05). Also, Swimming performance at of 10 meters) 8% (,10 to 20)6%( and 25 meters distance( 3/80%) growth in compare to control group that was significant(p <0.05) As well as in the number of hand strocke, Plyometric training group although had growth in swim 10 meters (11%), 10-20 meters (7.5%) and in 25 meters distance (5.33%) but the isnt significance (p>0.05). results indicate that six week upper body plyometric traning to an increase and improvement in the measured parameters, and can be used as a complementary training method in young swimmers.
