The Faculty of Sports Sciences at University of Isfahan, established in 2001, has emerged as a national leader in sports education and research, offering comprehensive programs in physical education, sports physiology, sports management, and sports psychology, while operating state-of-the-art sports facilities and laboratories.
British Journal of Sports Medicine (03063674)36(5)pp. 354-359
Objective: To assess the exposure of players to injury risk during English Premier League soccer matches in relation to selected factors. Methods: Injury risk was assessed by rating the injury potential of playing actions during competition with respect to (a) type of playing action, (b) period of the game, (c) zone of the pitch, and (d) playing either at home or away. In all, 10 games from the English Premier League 1999-2000 were chosen for analysis. A notation system was used whereby 16 soccer specific playing actions were classified into three categories: those inducing actual injury, those with a potential for injury (graded as mild, moderate, or high), and those deemed to have no potential for injury. The pitch was divided into 18 zones, and the position of each event was recorded along with time elapsed in the game, enabling six 15 minute periods to be defined. Results: Close to 18 000 actions were notated. On average (mean (SD)), 1788 (73) events (one every three seconds), 767 (99) events with injury potential (one every six seconds), and 2 (1) injuries (one every 45 minutes) per game were recorded. An overall injury incidence of 53 per 1000 playing hours was calculated. Receiving a tackle, receiving a "charge", and making a tackle were categorised as having a substantial injury risk, and goal catch, goal punch, kicking the ball, shot on goal, set kick, and heading the ball were all categorised as having a significant injury risk. All other actions were deemed low in risk. The first 15 minutes of each half contained the highest number of actions with mild injury potential, the last 15 minutes having the highest number of actions with moderate injury potential (p<0.01). The first and last 15 minutes of the game had the highest number of actions with high injury potential, although not significant. More actions with mild injury potential occurred in the goal area, and more actions with moderate and high injury potential occurred in the zone adjacent to the goal area (p<0.001). There was no significant difference between home and away with regard to injury potential. Conclusions: Playing actions with high injury risk were linked to contesting possession. Injury risk was highest in the first and last 15 minutes of the game, reflecting the intense engagements in the opening period and the possible effect of fatigue in the closing period. Injury risk was concentrated in the areas of the pitch where possession of the ball is most vigorously contested, which were specific attacking and defending zones close to the goal. Injury potential was no greater in away matches than at home.
Rahnama, N., Reilly, T., Lees, A., Graham-smith p.,
Journal of Sports Sciences (1466447X)21(11)pp. 933-942
Fatigue represents a reduction in the capability of muscle to generate force. The aim of the present study was to establish the effects of exercise that simulates the work rate of competitive soccer players on the strength of the knee extensors and knee flexors. Thirteen amateur soccer players (age 23.3 ± 3.9 years, height 1.78 ± 0.05 m, body mass 74.8±3.6 kg; mean ± s) were tested during the 2000-2001 soccer season. Muscle strength of die quadriceps and hamstrings was measured on an isokinetic dynamometer. A 90 min soccer-specific intermittent exercise protocol, incorporating a 15 min half-time intermission, was developed to provide fatiguing exercise corresponding in work rate to a game of soccer. The exercise protocol, performed on a programmable motorized treadmill, consisted of the different intensities observed during soccer match-play (e.g. walking, jogging, running, sprinting). Muscle strength was assessed before exercise, at half-time and immediately after exercise. A repeated-measures analysis of variance showed significant reductions (P < 0.001) in peak torque for both the quadriceps and hamstrings at all angular velocities (concentric: 1.05, 2.09, 5.23 rad.s-1; eccentric: 2.09 rad.s-1). The peak torque of the knee extensors (KE) and knee flexors (KF) was greater before exercise [KE: 232±37, 182±34, 129±27, 219±41 N.m at 1.05, 2.09 and 5.23 rad.s-1 (concentric) and 2.09 rad.s-1 (eccentric), respectively; KF: 126±20, 112±19, 101±16, 137±23 N.m] than at half-time (KE: 209±45, 177±35, 125±36, 214±43 N.m; KF: 114±31, 102±20, 92±15, 125±25 N.m) and greater at half-time than after exercise (KE: 196±43, 167±35, 118±24, 204±43 N.m; KF: 104±25, 95±21, 87±13, 114±27 N.m). For the hamstrings: quadriceps ratio, significant changes were found (P<0.05) for both legs, the ratio being greater before than after exercise. For fast:slow speed and left:right ratios, no significant changes were found. We conclude that there is a progressive reduction in muscle strength that applies across a range of functional characteristics during exercise that mimics the work rate in soccer.
Mathematical modeling and optimization of snatch technique based on dynamic synthesis is the main purpose of this study. The barbell trajectory is proposed as the main index which was evaluated experimentally by several researchers who introduced optimum trajectory according to percentage of their owners' success. We believe that in optimizing the barbell trajectory we should consider the mechanical principles. Therefore we use a five-link biomechanical model to evaluate its behaviour and to predict the optimum barbell trajectory which minimizes the specific mechanical criterion by using genetic algorithm (GA) which is theoretically and empirically proven to provide a robust search in complex spaces, thereby offering a valid approach to problems requiring efficient and effective searches. Comparing the results of this model and experimental observations of other researchers, we show an improvement to introduce a good predictive model. Using this model can help the coaches to improve the performance of weightlifters.
Gazzetta Medica Italiana Archivio per le Scienze Mediche (03933660)167(5)pp. 221-229
Aim. This study was designed to investigate the effect of continuous training on C-reactive protein (CRP), which is the most sensitive inflammatory marker for predicting of cardiovascular disease. Methods. This study was conducted on obese, female wistar14848 rats (325.6±4.93 g and 21 months old). A pilot study was carried out to investigate the difference in CRP between the obese (226.75±5.12 g and 4 months old) and thin (168.13±5.6 g and 4 months old) young rats, and also between the obese (325.6±4.93 g and 21 months old) and thin (246.87±4.79 g and 21 months old) rats (each group included 8 rats). Then, 32 rats were divided randomly into control and experimental groups and in each group the related sub-groups were chosen randomly. An experimental training programme was carried out for five days a week at a definite treadmill speed for 12 weeks. Blood samples were drawn at three phases of pretraining, mid-training and post-training. High-sensitivity CRP was measured with an immunoturbidimetric method. Results. Repeated-measures ANOVA showed that the reduction in CRP levels was not significant (P=0/08) in the fast six weeks but CRP decreased significantly (P<0.0001) after 12 weeks. Conclusion. It can be concluded that the decline in this inflammatory marker after a period of continuous training attenuated the atherogenesis process.
Rahnama, N., Younesian, A., Mohammadion, M., Bambaeichi e., E.
Journal Of Research In Medical Sciences (17357136)14(6)pp. 335-341
BACKGROUND: The association between the lipid profiles level and the incidence and severity of coronary heart disease (CHD) is very pronounced in epidemiological studies, and an inverse relation between physical fitness and the incidence of coronary heart disease has been observed in many studies. The aim of this study was to investigate the impact of a soccer match on lipid parameters of professional soccer players. METHODS: Twenty two professional soccer players participated in the study. Blood (10ml) for determination of lipid profiles was obtained at rest and immediately after a 90 minute soccer match. Lipid parameters were measured using Boehringer Mannheim kits and Clinilab and BioMerieux analyser. RESULTS: The results of this study showed that the triglyceride was significantly higher before the match than afterwards (159.09 ± 58.2 vs. 88.63 ± 34.1 mg/dl, p < 0.001), whereas the low-density lipoprotein (LDL) was lower before the match than after it (98.04 ± 28.9 vs. 112.31 ± 30.5 mg/dl). Moreover, there were no significant differences in cholesterol concentration (171.4 ± 30.28 mg/dl vs. 173.18 ± 32.75 mg/dl) and high-density lipoprotein (HDL) concentration (34.04 ± 5.58 mg/dl vs. 34.4 ± 4.6 mg/dl) between before and after the match. CONCLUSIONS: Although the soccer competitive match has no favourable acute effect on lipid profiles, the lower rate of LDL, cholesterol and triglyceride as well as the higher level of HDL in players suggest a beneficial effect of regular soccer training on arthrosclerosis and perhaps on CHD risk as well.
The barbell trajectory of snatch weightlifting has been investigated by several researchers. They suggested three optimal trajectory patterns (type A, B and C). But, there is no agreement for introducing the best overall trajectory. One probable reason would be this idea that the selected criterion used by the previous researchers might not be appropriate. Therefore we used a mathematical approach to judge between the conflicts. We made a multi-segments biomechanical model to evaluate the snatch motions while considering the selected mechanical cost. This method is an appropriate tool for coaches to examine several trajectories for making a good decision.
International Journal Of Preventive Medicine (20088213)1(2)pp. 124-130
Objectives: Supervised exercise cardiac rehabilitation programs have been suggested to all patients specially patients with postmyocardial infarction (MI) for many years. However, limited information is available on the usefulness of exercise rehabilitation programs in chronic MI. The aim of this study was to evaluate the outcome of supervised exercise training on MI patients by measuring both physical and physiological factors. Methods: This was a semi-experimental randomized study. Itincluded seventy two (35 cases, 37 controls) post-MI patients aged 40 to 67 years. They were randomly selected from those with MI based on WHO criteria who were referred to cardiac rehabilitation unit of Isfahan Shahid Chamran cardiovascular research center. After initial measurements including weight, height, functional capacity, diastolic blood pressure (DBP) and systolic blood pressure (SBP) in both resting and exercise states, patients were randomized into either the training group (n=35) or the control group (n =37). The training group had supervised aerobic training program, three times a week, with 60-70% of the maximal heart rate (HR) reserve for two months. After the training program was completed, all measurements were repeated in both groups. Data were analyzed using one-way analysis of variance (ANOVA) with repeated measures. Results: Patients in exercise group showed statistically significant improvement in resting HR (81.27±7.75 bpm vs. 74.17±10.11bpm, p≤0.001), resting SBP (125.92±9.30 mmHg vs. 123.54±6.82 mmHg, p≤0.01), SBP peak (150.22±7.12 mmHg vs. 133.54±6.82 mmHg, p≤0.001), HR peak (132.51±3.06 bpm vs. 142.00±3.14bpm, p≤0.001), and exercise capacity (8.49±1.18 METs vs. 9.42±1.19 METs, p≤0.01). Conclusions: The results from the study showed that a 2-month exercise rehabilitation program in post-MI patients is useful for improving both blood pressure and exercise capacity and should be encouraged more commonly.
Sadeghipour, H.R., Rahnama, A., Salesi, M., Rahnama, N., Mojtahedi, H.
International Journal Of Preventive Medicine (20088213)1(4)pp. 242-246
Objectives: The aim of this study was to investigate the relation between C-reactive protein (CRP) with physical fitness, physical activity, obesity, and selected cardiovascular risk factors in schoolchildren. Methods: Forty-four boy schoolchildren (mean ± SD: age 10.25 ± 0.75 years, height 144 ± 0.2 cm, body weight 46.1 5± 4.59 kg, body mass index 22.16 ± 2.16 kg/m2) voluntarily participated in this study. Physical fitness and physical activity were assessed using the 20-meter fitness test. Adiposity was estimated using body mass index. Blood samples were taken after an overnight fast and measured for CRP, LDL, HDL and cholesterol. Pearson's correlation was calculated to determine the relations between these factors. Results: Mean (SD) CRP concentration was 1.07 (0.82) mg/l. A significant correlation was observed between CRP and VO2max (r=-0.45, P= 0.001), body mass index (r=0.55, P=0.000) and cholesterol (r=-0.35, P=0.04). No significant relation was found between CRP and physical activity, LDL and HDL (P> 0.05). Moreover, significant associations were observed between body mass index and VO2max (r=-0.33, P=0.02) and physical activity (r=-0.43, P=0.04). Conclusions: Body mass index was the most powerful predictor of serum concentrations of CRP in schoolchildren. It may be an important factor to control body weight to prevent an increase in serum CRP in children and to help the primordial prevention of chronic diseases.
Journal of Isfahan Medical School (10277595)28(106)pp. 143-148
Background: Rate of injuries among female athletes is higher than male. Cyclic sex hormones fluctuation during the menstrual cycle might play an important role in this respect. The aim of this study was to investigate the rate of female athletes' injuries in different phases of menstrual cycle. Methods: Athletes from twenty clubs participated in Iran league competition (2006-2007) were studied. Information of menstrual cycle and athletes' injuries was collected using injury report form completed by athletes and team physicians. Findings: The rate of injuries, ligament injury and also anterior cruciate ligament injuries were significantly higher in luteal phase, compare to ovulation and follicular phases (P < 0.01). When data were analysed based on the duration of each phase, more injuries were observed in the ovulation phase. Conclusion: There is circamenstrual variation in female athlete's sport injuries. So, for minimising rate of injury, female athletes should avoid from dangerous situations in training and competition during ovulation phase.
Journal of Isfahan Medical School (10277595)28(108)pp. 327-338
Background: The purpose of this study was to compare four resistant training protocols on level of human growth hormone secretion in beginner male athletes. Methods: In a semi-excremental study, 12 healthy male subjects were chosen randomly among beginner athletes with mean age: 22.3 ± 2.2 years, height: 178.5 ± 4.03 cm, weight: 73.9 ± 3.02 kg and body mass index: 23.26 ± 1.1 kg/m2. Bilateral knee extension exercise used as the exercise movement. Each of athletes was participated in four training protocols and concentration of human growth hormone was measured before and immediately after each exercise. Interval between executing each of exercise protocols was one week. Before implementing the exercise protocol, 1RM of bilateral knee extension was measured. Protocol 1 included 5 set at 90% of 1RM, with 3-min rests until tired. In second, third and fourth protocols, after doing last set (fifth set) and 30-seconds of rest, an additional set with 50%, 30% and 20% of 1RM until tired was performed. The obtained data were analyzed using analysis of variance (ANOVA) with repeated measures for differences among training protocols, Scheffe post hoc comparison and students paired t-test for differences between correlated means. Findings: The executing second protocol (T50) and third protocol (T30), increased human growth hormone concentrations after exercise significantly (P < 0.001); whereas firs protocol (T1) and fourth protocol (T20) caused no significantly change in human growth hormone concentrations after exercise (P > 0.05). Conclusion: The results of present research showed that adding a set of 50% or 30% of 1RM until tired to a training program done by high intensity and low repetition will increase amount of hormone secretion significantly after exercise.
