Year:2004 | Volume:- | Issue:18|Papers Count:17

Low back pain reduces the physical and social activities as well as the joy of life. The ‎objective of this study was to assess the importance of the muscle endurance and ‎anthropometry as risk factors in chronic low back pain as well as the necessity for the ‎continuation of the treatment period. Pain, disability, muscle endurance of trunk ‎flexors and extensors, lower limbs extensors and somatotype of all subjects were ‎measured. All the measurements on patients were repeated after a three-month ‎exercise therapy. Results showed that pain and disability decreased after the treatment ‎by 58% and 53%. On average, muscle endurance of patients was 62% lower than that ‎of the normal group. Anthropometry and somatotype of both groups were similar. ‎After the treatment, the muscle endurance of trunk flexors did not improve, while the ‎endurance in extensors significantly improved by 51% (p=0.01) ‎ The muscle endurance in low back pain patients were affected. The applied exercise ‎therapy reduced significantly the pain and disability, and increased the muscle ‎endurance in extensors. the abnormal flexors endurance is a risk factor for repetitive ‎LBP‏.‏

Reaction time (RT) is a very important factor in skilled performance. Precue is one of ‎the effective factors on RT. The results of studies on this factor have shown a ‎reduction in RT as the function of precue; but the majority of these researches have ‎been performed on aiming tasks. The present research was performed to test the ‎hypothesis that RT in a force production task is a function of precued parameters. A ‎mixed 3-functional design was performed on 16 (8 male and 8 female) volunteers: ‎non-athlete, right-handed students aged between 20 and 25. The subjects performed a ‎total of 2400 trials over 5 sessions on successive days (4 blocks out of 120 block-trials ‎per session) under different numbers of precue (0-3) using parameter precuing ‎apparatus. This task required the production of defined isometric force (3 or 6 kg) ‎toward inside or outside, with right or left upper limb acting as quickly and accurately ‎as possible after displaying precue(s) and stimulus. The subjects' RT in different levels ‎of independent variables was analyzed using 3-facotr experiment (number of precued ‎parameters* gender * session) with repeated measurements on 2 of these factors (number of precued parameters and session). The results indicated a significant ‎reduction in RT with an increase in the number of precued parameters (P<0.05). The ‎main effects of gender and session were not significant (P>0.05), but all of the ‎interactions were significant (P<0.05).‎

During a soccer match, players exercised at a relatively high intensity. It is therefore ‎not surprising that fatigue occurs causing performance to fall off in the laer stages o f ‎the match in the second half. Since decision-making as well as technical and tactical ‎aspects are important elements in soccer, towards the end of the match fatigue can ‎cause deteriorations in mental performance. Eric Newsholme et al. 91987) were the ‎first to hypothesize such a role for brain Serotonin (5-HT). Recently hypotheses have been developed and there has been an interest in the ‎possible role of the CNS in fatigue. A few mechanisms have been suggested to cause ‎central fatigue such as changes in neurotransmitters of serotonin, dopamine and ‎acetylcholine. An increase in 5-HT, DA and ACh synthesis and metabolism typically ‎occur in response to an increase in delivery of blood-borne Trp, Tyr and cholin to the ‎brain and central serotonergic, dopaminergic and cholinergic systems activated by ‎stress, exercise, eating, supplementation and medication. Thus fatigue could affect all ‎behavioral and physiological functions that could positively or negatively affect ‎power or endurance of performance. Thirty adult male soccer players were divided ‎into five groups randomly. Placebo group and experimental group whose ingestion ‎flavored water, glucose, BCAAs, lecithin and hydroalchoholic extract of sage, 2.5h ‎before and during soccer-specific intermittent running protocol‏.‏ The peripheral serotonin and dopamine levels were determined through venous blood ‎samples collected throughout the last 2.5 hours, half-time and immediately after ‎soccer-specific intermittent running protocol. Subjects also completed the POMS, ‎CWT, RPE, and measured exercise time to fatigue. Based on our observations that ‎fatigue during soccer-specific intermittent protocol towards the end of the soccer ‎match in adult male soccer players is associated with an increase in barin 5-HT and a ‎reduction of brain dopamine, our working hypothesis is that a low ratio of 5-HT/DA ‎and high ACh level in the brain prevent mental fatigue and subsequently enhance ‎performance in soccer matches. Increased serotonergic activity may induce fatigue ‎through inhibition of the dopaminergic system and or the reduction of motivation to ‎perform. Furthermore, serotonergic activity can affect the hypothalamic-pituitary-‎adrenal axis, thermoregulation, pain, mood, motor coordination and other behaviors or ‎perceptions depending on specific situations such as physical activity‏.‏

This study examined the velocity, acceleration, ground reaction, stopping and take-off ‎forces, energy and power consumption during running in a hundred-meter event. An ‎electronic telemetry system was designed and constructed for kinematic ‎investigations, while video graph being used to analyze kinetic characteristics for ‎each stride. During the constant speed, the ground reaction force, stopping and take-‎off forces, mean energy and power consumption in each stride were also estimated. ‎The performance criterion was time tp each 10m. We have used Microsoft Excel to ‎trace the variation of velocity and acceleration of each subject. Three male sprinters‎ (tops of a national team) volunteered as subjects for the study. The sprinters records ‎were 10.8 second in the 100-meter run. The study demonstrates how the velocity ‎increases widely at the beginning, remains constant for sometime and then decreases, ‎when the runner reaches the end of the run. On the contrary, the acceleration is ‎maximum just at the take-off, decreases to zero when the sprinter reaches his ‎maximum velocity, decelerates to zero when the sprinter reaches his maximum ‎velocity, and then decelerates arriving to the end of run. The results on force ‎measurements showed that the sprinter with larger strides presents larger ground ‎reaction, stopping and take-off forces which agree well with what the other ‎researchers have obtained‏.‏

The present investigation aims at determining the depression variables among the ‎athlete vs. non-athlete male and female high school students. It is a descriptive design ‎and has been carried out as a filed study. The participants comprised 800 students, ‎‎400 of which were male and female athlete students and the rest (i.e. 400) were non-‎athlete male and female students. To determine the depression variables, the ‎investigator applied DAS questionnaire for data collection. Results manifested that ‎except for love, there is significant differences between the athlete and non-athlete ‎students in terms of depression variables such as approval, success, perfectionism, ‎justification, definite power, and freedom to vote‏.‏

Based on mitochondrial aging theory, oxidative stress plays a major role in aging and ‎age related degenerative diseases. Since oxygen consumption and ROS (reactive ‎oxygen species) rate increase during aerobic exercise, we supposed that heavy aerobic ‎training can lead to enhance mtDNA deletion. Two experimental groups of adult male ‎Wistar 14848 rats with 2 month-age were trained by running on a treadmill for 3 ‎months (5day/wk, E40: N=10, 40 m/min, 20 min, E20: N=10, 20 m/min, 40 min, ‎and slob=6%). mtDNA deletion of soleus muscle in these groups were compared with ‎that in two control groups (Con1: N=10, aged 2 months and Con2" N=10, aged 5 ‎months) and two sedentary groups that participated only in aerobic exercises at the ‎end of the study (CE40: N=10, 40m/min, 20min, CE20: N=10, 20 m/min, ‎‎40 min, and slob=6%). Multiplex PCR products based on the agar (2%) indicated that ‎mtDNA deletion (4.6kb0 induced by heavy aerobic training in E40 group. This ‎deletion was not shown in other groups. This result was confirmed by sequencing ‎analysis‏.‏

The present study was conducted to compare function of some muscles of shoulder: ‎biceps, deltoid, pectorals major and triceps) in pull-up, push-up and modified pull-up ‎tests. Subjects included fourteen 12 year old healthy boys, with average height of ‎‎148±3.23 cm and weight of 39.23±2.4 kg with maximum of a 6 month-athletic period.‎ Function of each muscle in shoulder (biceps, deltoid, pectorals major and triceps) was ‎recorded by lead and electrical current circuit during the test. Statistical analysis using ‎SPSS: PC was performed. ANOVA was employed to test the differences (P<0.05).‎‏ ‏In of pull-up in standing position, biceps and triceps obtained maximum rate of ‎activity muscles. Also, pectorals major and deltoid muscles in push-up were more ‎active than the other muscles. It was concluded that pull-up and push up have similar ‎effects on the activity of the above muscles.‎

The aim of the present study was to examine and compare happiness in athletic and ‎non-athletic women. 120 female university students (60 athletes and 60 non-athletes) ‎were randomly assigned to two groups and Oxford Happiness Inventory (reliability ‎and validity has been shown in Iran) was used. The results showed that athletic ‎women were in higher level at the five scales (mental health, self-esteem, efficiency, ‎satisfaction and positive mood). Also, there was a significant difference between level ‎of happiness in two groups (P=0.001).‎

In this research 25 male physical education students (age: 22.4 Y., weight: ‎‎66.58±7.53 kg, height: 171±5.16 cm) participated. All subjects performed leg ergometer (Wingate protocol) and Rast Filed test. The finding of this research ‎absolute Wingate Rast Test (R=0.85, P<0.05). No significant relationship was found ‎between estimated manpower in Rast test and retest (R=0.87, P<0.05). Significant ‎relationship was found between estimated peak power Wingate test resistance optimal ‎work load (0.087, 0.075 kp/w); (R=0.99, P<0.05). No significant difference was found ‎between change in CPK enzyme after and before Wingate test (T=0.60, P<0.55). ‎Significant difference in CPK enzyme after Rast test (T=-4.16, P<0.002) showed ‎significant change in LDH enzyme after and before Wingate test (T=2.28, P<0.045) ‎and significant change in LDH enzyme after Rast test (T=-0.67, P<0.513). No ‎significant difference was found between intensive performance (0% HRR) in ‎Wingate and Rast Test (T=-0.51, P<0.167). The results indicate that Rast test has ‎validity and reliability to estimate the anaerobic capacity‏.‏

Modern methods for practice performable in general classes of body training are very ‎useful, achieving the goals of physical fitness programs such as an increase ‎in the power of heart, respiratory system, blood vessels and improvement of aerobic ‎potential. Surveys of the past reveal that the practices designed on the basis of for ‎tifying an energy instrument cause an increase in the output of that instrument, but the ‎question is raised whether the practices prepared to strengthen an energy instrument ‎are able to overshadow another energy system during a short time. Therefore, a study ‎was carried out on the effects of 6 successive weeks of practice inaerobically on the ‎aerobic power of non-athlete male students‏.‏