فصلنامه علوم زیستی ورزشی
پیاپی 24 (بهار 1394)

High intensity workout provokes damage in muscles with an effect on muscle physiology and function. Today, serum levels of creatine and aspartate aminotransferase are widely used as biochemical markers of muscle damage in order to determine the functional status of muscle tissues in both pathological and physiological conditions. This study investigated the effect of a futsal match on some biochemical markers of muscle damage such as creatine (Cr) and aspartate aminotransferase (AST). 20 professional female futsal players (mean ± SD: age 20.9±2.02 yr, height 1.63±0.05 m, weight 59.25±8.92 kg) participated in this study. The subjects were divided into experimental and control groups. 10 participants took part in a futsal match and 10 subjects did not participate in the match as the control group. 10 cc of blood were collected from both groups before, immediately after (first posttest) and 24 hours after the match (second posttest) to measure Cr and AST and were analyzed by biochemical methods. Analysis of variance with repeated measures and Bonferroni post hoc test were used for data analysis. The results showed a significant increase in AST immediately after the match (P≤0.05). But there was no significant difference between the groups. Cr showed a significant difference immediately after the match between the two groups (P≤0.05), that is to say it increased 21% in the first posttest in the experimental group compared with the control group. It can be concluded that a futsal match can increase serum concentrations of Cr and AST that represents the risk of muscle damage in female futsal players.

The purpose of present study was to examine the effect of caffeine consumption on substrate metabolism and time to exhaustion during exercise and one hour after exercise in athletic female. Eleven female athlete students (age 23±1.54 years, body weight 56.09±5.99 kg, and aerobic power 40.21±1.01ml/kg/min) volunteered and were randomly divided into three groups of control,placebo (starch capsule), and caffeine (5 mg/kg), in a crossover design. Exercise protocol included exhausting running on treadmill with 70% of intensity of maximal heart rate. Subjects’ respiratory gases were collected at 30 minutes before exercise in prostrate position, during exercise, and one hour after exercise-as EPOC. The amounts of fat oxidation, carbohydrate and energy expenditure were measured by indirect calorimeter.The data was analyzed using the Kolmogrov – Smirnov, ANOVA with repeated measures and LSD post-hoc tests, at significance level of P≤0.05. The results showed that with caffeine consumption carbohydrate oxidation was significantly increased (p<0.05), but there was no significant effect on fat oxidation (p>0.05). Furthermore, caffeine consumption had no significant effect on substrate metabolism EPOC (p>0.05), while it significantly increased time to exhausion (p>0.05). Therefore, female athletes can increse/improve the time to exhausion by consumption of caffeine supplements (5 mg /kg) 1 hour before exercise.

The aim of the present study was to investigate the response of plasma visfatin to resistance exercise intensity and its relationship with insulin resistance, growth hormone and IL-6. After familiarization and determining their maximum strength (1-RM), 15 healthy young subjects (age: 26.2±4.1 yr, weight: 75.1±9.1 kg) performed three resistance exercise sessions at intensities of 30%, 55% and 80% of 1-RM with equal volumes randomly with a one-week interval. Blood samples were collected before and immediately after the exercise and analyzed to measure glucose, insulin, growth hormone, interlukin-6 (IL-6) and visfatin. Results showed no significant differences among the responses of plasma visfatin, interlukin-6 and insulin resistance index to three different resistance exercise intensities (P>0.05). Irrespective of intensity, a session of resistance exercise had a significant effect (P<0.001) on all variables except for visfatin. No significant relationships were found among all measured variables (P>0.05). Based on the findings of the present study, it could be concluded that resistance exercise intensity was not an effective factor for the response of visfatin, IL-6 and insulin resistance index which might be due to small differences in energy cost of resistance exercise at different intensities but equal volumes. Since there was no significant relationship between visfatin and insulin resistance in response to resistance exercise, this adipokine cannot be involved in insulin resistance during exercise.

The evaluation and comparison of somatotype with elite athletes is a method to predict the chances of success in sports particularly in the Olympic sport of wrestling. The aim of the present study was to describe the somatotypic profile of 9-13-year-old boys in northern, mountainous and desert areas with a territorial planning approach and an emphasis on the geographical areas potential for wrestling. The present study was descriptive and field study. The statistical population consisted of those volunteer boys aged between 9 and 13 who participated in summer leisure programs of Basij Sport Organization. The sample included 717 boys (206 subjects from northern areas, 241 subjects from mountainous areas and 270 subjects from desert areas) who were selected from Kurdistan, Kermanshah, Ilam, Lorestan, Mazandaran, Gilan, Gorgan, Markazi, Qom and Kerman provinces. According to the guidelines on ISAK, selected anthropometric variables were measured and somatotypes were calculated by Heath-Carter method. Data were analyzed using ANOVA and x2 tests. Results of ANOVA showed significant differences in all three components of endomorph (F=33.99, P<0.001), ectomorph (F=4.18, P=0.016) and mesomorph (F=15.06, P<0.001) among three geographical areas of northern (wet), west (mountain), central and southern (desert). The most frequent somatotype was endomorphic-mesomorph in northern areas (x2=176.2, P<0.001, n=60), mesomorph-ectomorph in mountainous areas (x2=117.9, P<0.001, n=50) and endomorphic-mesomorph in the desert areas (x2=202.8, P<0.001). The finding of the present study showed that the northern and desert areas may be more talented in heavier categories of wrestling because of their higher percentage of endomorphic-mesomorph somatotype

Researchers and coaches are constantly looking for the most effective ways to enhance athletic performance. The aim of this study was to investigate the response of strength, power and muscle endurance to resistance training with different rest intervals. 16 male volunteers were selected and divided randomly into two groups. Group A (n=8, age 22±2.55 yr, height 174.20±6.14 cm, weight 64.20±6.33 kg) performed resistance training with constant rest intervals (120 sec.) and group B (n=8, age 22±3.54 yr, height 176.40±6.50 cm, weight 64.60±6.38 kg) with incremental rest intervals (90, 120, 150 sec.) 3 days per week for 6 weeks. To determine strength, power and muscle endurance, 1RM, bench press, throwing medicine ball and maximum repetition of bench press with 30% of 1RM tests were used respectively. Blood samples were collected 3 minutes before and 2 minutes after the 17th session to measure blood lactate. Paired samples and independent samples t tests were used for data analysis (α<0.05). Results showed that strength, power and muscle endurance significantly increased in both groups (P<0.05), but group B showed a greater percentage change in all tests. Blood lactate significantly increased after the resistance training compared with the rest interval but this increase was less in group B. It can be concluded that resistance training with progressive rest intervals is more important for increasing strength, power and muscle endurance compared with constant rest intervals.

The most important physiological role of apelin as a novel adipokine is co- relation with insulin hormone. The aim of this study was to investigate the effects of 12 weeks combined training on plasma apelin and insulin resistance index in overweight females. Therefore, 40 non athlete and over weight female students (BMI, 25-30), were selected and divided randomly in two experimental and control groups, equally. Training program was done seven days a week for 12 weeks. The endurance training program, which was performed four sessions per week, included intermittent running and walking. Two sessions per week were assigned to progressive resistance training consisted of circuit trainings. One session per week was also allocated to handball training. Blood samples were taken in fasting state from all subjects. Plasma apelin and insulin concentrates were determined by ELISA test. The statistical analyze of research was done by Repeated ANOVA (2×2), at the significance level of p

The aim of this study was to investigate the effect of acute resistance exercise with different movement orders on fatigue parameters (serotonin and RPE test) in non-athlete men (normal weight and obese). 26 male university students were purposively selected and assigned to obese (n-11) and normal weight groups (n=15). In the first session, half of the subjects (both obese and normal) randomly performed resistance protocol A (resistance exercise from large to small muscles) and the rest of the subjects performed resistance protocol B (resistance exercise from small to large muscles). The second session was three days later with reverse protocols. In each session, subjects performed 3 sets to exhaustion for 9 movements with 10RM. In each session, blood samples were collected before, immediately after and 30 min. after the exercise. Results using ANOVA with repeated measures showed that serum serotonin concentration significantly increased in both obese and normal groups (P<0.05) immediately after the protocol B (not protocol A) and returned to the baseline after 30 min of recovery. However, resistance exercise order had no effect on serum cortisol changes. In addition, both groups had higher RPE during resistance protocol B (P>0.05) although the difference was not significant compared with the protocol A. Overall, the findings of this study showed that when the resistance movements are preceded by small muscles, greater fatigue will happen, but obesity is ineffective in this regard, although obesity was associated with milder cortisol changes.

Animal studies have reported very useful properties including weight loss and improved body composition for conjugated linoleic acid (CLA). However, there is limited information about the combined effect of resistance training and CLA supplementation. Therefore, the effect of CLA supplementation and resistance training on body composition, serum leptin and muscle strength in non-athlete men was examined in this study. In a quasi-experimental trial with double-blind design, 23 non-athlete men were randomly assigned to two groups: training + supplement (n=11), and training + placebo (n=12). Both groups performed 6 weeks (3 sessions per week) of resistance training program based on the Kramer (2004) protocol. The experimental group received 3 capsules (1000 mg) of CLA supplement and the control group ingested 3 capsules of placebo (olive oil) per day. Muscular strength, body composition and serum leptin were measured in the beginning and at the end of the study. Data were analyzed using dependent and independent t tests. Based on the findings, CLA + resistance training supplementation significantly decreased fat mass and serum leptin and significantly increased non-fat mass compared with placebo + resistance training (P˂0.05) while the lower and upper body strength of both groups were not significantly different. According to the results, it can be stated that resistance training combined with CLA supplementation can improve body composition and decrease serum leptin in non-athlete men. But it does not necessarily lead to a significant improvement in lower and upper body strength.

The aim of this study was to investigate the effect of different age groups and protocol type on respiratory function in men following a progressive aerobic exercise protocol. 37 healthy males (mean age of 12.7±1.7, 34.3±4.9,52±5.7 yr) were selected voluntarily. At first, the leg ergometer was used with constant 50 rpm and the initial intensity of 50 watts and 25 watts were added every two minutes. After an hour of rest, hand ergometer test was carried out with the same intensity and forced vital capacity and expiratory volume were measured by spirometry before and immediately after the ergometers. Data were analyzed using two-way analysis of variance, ANOVA, paired t test and Tukey post hoc test at P<0.05. The results showed that age and protocol type had a significant effect on FVC and FEV1, that is to say FVC level was significantly lower in young subjects than the elderly and middle-aged subjects (P<0.05) and it was higher in the middle-aged than the elderly (P<0.05) following leg and hand ergometers. In addition, FEV1 was significantly higher in the middle-aged than the elderly following the ergometers (P<0.05) and lower in the young subjects than the elderly and middle-aged (P<0.05). The interactive effect of age and exercise protocol type on respiratory parameters was determined. In addition, it became clear that the leg ergometer increased FVC in young subjects and improved FEV1 in all three age groups, but hand ergometer improved only FEV1 in young and middle-aged subjects.