سال:1390 | دوره: | شماره: |تعداد مقالات:11

Exercise induced asthma (EIA) is a transient increase in airway resistance after intensive exercise and can be measured as a decline in forced expiratory volume in one second (FEV1). The condition is due to increased training load and inhalation of cold and dry air. Several studies have shown that eucapnic voluntary hyperpnea challenge test (EVH test) is a very sensitive and specific diagnostic method. EVH test develops EIA by hyperventilation of dry gas and the test achieves the same airway obstruction as training in cold and dry air. The test is better than the previously used methacholine challenge test.

Purpose: Obesity is a common nutritional problem in both developed and developing countries. The aim of this study was to determine the prevalence of overweightness and obesity using both bioelectrical impedance analysis (BIA) and body mass index (BMI). Methods: In this cross-sectional study, 288 healthy college students were selected. Socio-economic status questionnaires were completed and subjects’ anthropometric features were measured by a trained nurse. BMI was calculated and body fat mass (BFM) and body fat percent (BF%) were obtained using BIA method by hand­-to-hand Omron BF-500 set.Results: Mean age of the subjects was 21.1±1.7 years. Based on BMI, 2.6% of males and 2.2% of females were obese while 15.7% and 9.6% were diagnosed to be overweight respectively. The correlation between BMI values and BFM were 0.883 and 0.908 in males and females respectively (P<0.001). Furthermore, BF% had a significant correlation with BMI in both males and females (P<0.001).Conclusions: Our survey demonstrated a lower prevalence of obesity and overweightness in college students compared with Iranian general population, especially in females. Additionally, BIA method was shown to be closely correlated with and as much valuable as BMI in regard to detection of obesity.

Purpose: Although the contribution of physique and body composition in soccer performance was recognized, these parameters of physical fitness were not well-studied in adolescent players. Aim of this study was to investigate physique and body composition across adolescence.Methods: Male adolescents (N=297 aged 12.01-20.98 y), classified into nine one-year age-groups, child (control group, N=16 aged 7.34-11.97 y) and adult players (control group, N=29 aged 21.01-31.59 y), all members of competitive soccer clubs, performed a series of anthro­pometric measures (body mass, height, skinfolds, circumferences and girths), from which body mass index (BMI), percentage of body fat (BF%), fat mass (FM), fat free mass (FFM) and somatotype (Heath-Carter method) were calculated.Results: Age had a positive association with FM (r=0.2, P<0.001) and FFM (r=0.68, P<0.001), and a negative association with BF (r=-0.12, P=0.047). Somatotype components changed across adolescence as well; age was linked to endomorphy (r=-0.17, P=0.005), mesomorphy (r=0.14, P=0.019) and ectomorphy (r=-0.17, P=0.004). Compared with age-matched general population, participants exhibited equal body mass, higher stature, lower body mass index and lower BF.Conclusions: During adolescence, soccer players presented significant differences in terms of body composition and physique. Thus, these findings could be employed by coaches and fitness trainers engaged in soccer training in the context of physical fitness assessment and talent identification.

Purpose: Aerobic exercise has been identified as the main treatment for type 2 diabetic patients. Such an exercise, however, is usually repined by some of patients who suffer from lack of stamina. Therefore, whole body vibration has recently been introduced as a passive intervention. The present study aimed at comparing how aerobic exercise and whole body vibration affect glycaemia control in type 2 diabetic males. Methods: Thirty diabetic males were divided into three groups, namely aerobic exercise (AE), whole body vibration (WBV), and control. Aerobic exercise schedule consisted of three walking sessions a week, each for 30-60 minutes and in 60-70% of maximum stock heartbeat. Vibration exercise was composed of 8-12-min stand-up and semi-squat positioning in frequency of 30 Hz and amplitude of 2 mm. Concentrations of fasting glycosylated hemoglobin, fasting glucose, and insulin were measured in the beginning of the trial, after the fourth week, and after the eighth week.Results: After 8 weeks of exercise, no significant difference was detected in concentrations of fasting glycosylated hemoglobin and insulin between the groups (P=0.8, P=0.1). There were no significant differences in any of the variables between AE and WBV (P>0.05). But a more significant decrease in fasting glucose was observed in exercise groups (AE and WBV) compared with control group (P=0.02).Conclusions: The present study showed that AE and WBV identically stimulate metabolic system. Thus, it can be concluded that type 2 diabetic patients lacking stamina for aerobic exercise can opt for vibration exercise as an effective substitute.

Purpose: To determine whether a fifteen-minute water immersion treatment affects the normal ankle joint position sense (JPS) at the middle range of dorsiflexion and plantar flexion actively and passively.Methods: Thirty healthy female volunteers aged between 18 and 30 years were treated by a 15-minute cryotherapy (6±1oC). The subject’s skin temperature over antromedial aspect of dominant ankle was measured by the Mayomed device before, immediate and 15 minutes after water immersion. Ankle JPS was tested trough the pedal goniometer at 3 stages similar to the skin temperature. ANOVA (a=0.05) was performed on each of variables using SPSS 19.0 software.Results: Skin temperature was seen to decrease after water immersion but subjects did not return to pre-test skin temperature after 15 minutes (P<0.001). The research found no significant difference in JPS at middle range of dorsiflexion and plantar flexion actively and passively before and after cryotherapy.Conclusions: These findings suggest that 15-minute water immersion at 6oC dose not significantly alter the middle range of plantar flexion/ dorsiflexion JPS at the ankle and is not deleterious to JPS.

Purpose: This study was designed to compare the effects of two different relaxation techniques, namely progressive muscle relaxation (PMR) and autogenic relaxation (AGR) on moods of young soccer players.Methods: Sixteen adolescent athletes (mean age: 14.1±1.3) received either PMR or AGR training. Using Profile of Mood States-Adolescents, their mood states were measured one week before relaxation training, before the first relaxation session, and after the twelfth relaxation session.Results: Mixed ANOVA revealed no significant interaction effects and no significant main effects in any of the subscales. However, significant main effects for testing sessions were found for confusion, depression, fatigue, and tension subscales. Post hoc tests revealed post-intervention reductions in the confusion, depression, fatigue, and tension subscale scores.Conclusions: These two relaxation techniques induce equivalent mood responses and may be used to regulate young soccer players’ mood states.

Purpose: To translate long form, interview-administered International Physical Activity Questionnaire (IPAQ) from English to Persian and evaluate its validity, reliability and reproducibility.Methods: A forward-backward translation procedure was followed to develop the Persian version of the IPAQ. A total of 218 respondents (53.7% women, aged 22-76 yr) completed the Persian version in Tehran, Iran. To examine the test-retest reliability, 48 healthy volunteers completed the IPAQ twice during a 7-day period. The PA indicators derived from the IPAQ were assessed for reliability and were compared with aerobic fitness and body mass index (BMI) for construct validity.Results: In general, the questionnaire was received well and all domains met the minimum reliability standards (intra-class correlation [ICC]> 0.7), except for Leisure-time physical activity (PA). Aerobic fitness showed a weak positive correlation with all of the PA results derived from the IPAQ. A significant correlation was observed between the IPAQ data for total PA and both aerobic fitness (r=0.33, P<0.001) and BMI (r=0.26, P<0.001). Performing a known group comparison analysis, the results indicated that the questionnaire was discriminated well between the subgroups of the study samples expected to be different in their physical activity.Conclusions: The Persian version of the long form, interview-administered IPAQ had an acceptable reliability and validity for assessing total PA in our Iranian sample of individuals. It may be a useful instrument for generating internationally comparable data on PA.

I would like to commend Dr Farzin Halabchi and colleagues regarding their excellent review article of “Sudden cardiac death in young athletes”. The identification of underlying cardiovascular disease is a primary screening objective of physicians who care for athletes. I would like to take this opportunity to clarify some points made in the article and make some suggestions for future screening and research.There is a lot of debate regarding the use of electrocardiogram (ECG) as a universal screening tool for cardiac diseases in the preparticipation physical exam (PPE). Italy has employed this and has shown a significant decrease in their athletes' mortality from sudden cardiac death (SCD).

The article by Halabchi et al. provides a comprehensive, thoughtful and balanced analysis of the literature on sudden cardiac death (SCD) in young athletes. The article is unique in providing a special perspective for Asia as contrasted with those in Europe and the United States. This aspect is extremely important to recognize for the management of young athletes in different parts of the world.In the United States, the history and physical examination has been the standard of cardiovascular screening for competitive athletes, although several studies have questioned the efficacy of the screening history and physical examination  alone in identifying athletes at risk for cardiovascular adverse events.

It is a great pleasure to receive two valuable comments about our article regarding sudden cardiac death (SCD) in young athletes from two well known experts working in the field of preparticipation evaluation and prevention of sports injuries. We, as authors, generally agree with both authors' comments. However, some considerations should be re-emphasized here.

Respecting the recent promotion of sports medicine in different communities as a new field in medicine, involvement of medical students in sport medicine research similar to other medical research fields seems to be necessary. In this letter, we describe our experience regarding establishment of a student research committee in Sports Medicine Research Center (SMRC) of Tehran University of Medical Sciences. Fortunately, many medical students joined to this committee. These students can guarantee the successful future of this new branch of medicine.