Sport science Research Center

Tehrān, Iran

Sport science Research Center

Tehrān, Iran

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Liu T.-H.,Taipei Physical Education College | Chang C.-K.,Sport Science Research Center
Journal of Exercise Science and Fitness | Year: 2010

Supplementation of β-hydroxy-β-methylbutyrate (HMB) has been suggested to help increase muscle mass or reduce body fat in resistance-trained subjects and patients in catabolic states. The aim of this preliminary study was to investigate the effect of oral supplementation of 3 g·day-1 HMB for 3 days on body composition and exercise performance in well-trained female judo athletes during energy restriction. Eight female judo athletes were matched for body weight and divided into HMB and control groups. All subjects consumed food containing 20kcal·kg-1 with carbohydrate 3.6g·kg-1, protein 1.33g·kg-1, and fat 0.03g·kg-1 each day. Body weight and body fat percentage were significantly decreased in the HMB group, but remained unchanged in the control group after the study period. Muscle mass and the anaerobic performance of the lower and upper body were unchanged in both groups. The HMB group showed significant increases in total cholesterol, blood urea nitrogen, and uric acid after the study period. The control group did not show any significant changes in all blood parameters. This study suggested that short-term supplementation of HMB during energy restriction may help to reduce body fat but has no effect on lean body mass or exercise performance in female athletes. © 2010 Elsevier (Singapore) Pte Ltd. All rights reserved.


Hsieh K.-C.,Charder Electronic Co. | Lu H.-K.,Sport Science Research Center | Chen C.-H.,Tunghai University
African Journal of Biotechnology | Year: 2011

The criterion validity of foot-to-foot (ZF-F) by bioelectrical impedance analysis (BIA) in a standing position measuring models was referenced by dual-energy X-ray absorptiometry (DEXA) and hand-tofoot (ZH-F). In order to cross match analysis, both of the ZH-F and ZF-F measuring by BIA were performed in the same event to the identical subject, simultaneously. 105 males (7 to 70 years old) and 108 females (7 to 67 years old) were measured by BIA and DEXA. The ZF-F value was 481.85 ± 63.37 ohm in male and 554.35 ± 74.97 ohm in female. The ZH-F value was 586.82 ± 81.56 ohm in male and 703.28 ± 97.70 ohm in female. Regression equations for ZF-F and ZH-F were ZF-F = 0.926 ZH-F - 63.093, (R = 0.85) in male and ZF-F = 0.909 ZH-F - 86.673 (R = 0.86) in female. The fat free mass (FFM), measured by DEXA was 49.42 ± 10.03 kg in male and 34.52 ± 4.45 kg in female. The correlation (R value) for ZF-F to DEXA was 0.93 and for ZH-F was 0.96 in male, and 0.85 and 0.87 in female, respectively. The high correlation between ZH-F and ZF-F vs. whole body DEXA in both male and female renders it applicable to develop the clinical instrument by foot-to-foot measuring models by BIA in standing position. © 2011 Academic Journals.


Chen C.-M.,National Chi Nan University | Chang C.-K.,Sport Science Research Center | Yeh C.-Y.,National Chi Nan University
International Journal of Public Health | Year: 2012

Objective Previous studies on the relationship between sleep duration and bodymass index (BMI) have shown inconsistent results by using estimation strategies within the framework of ordinary least squares (OLS). This study examined the relationship between sleep duration and BMI by using quantile regression to account for the potential heterogeneous effect of sleep duration on BMI in different BMI categories. Methods The data of 2,392 adults were from the 2005 Panel Study of Family Dynamics in Taiwan. The dependent variable was BMI of the respondents. Both OLS and quantile regression models were used for comparison. Results The OLS model does not show significant relationship, while the quantile regression model shows a U-shaped relationship between sleep duration and BMI beyond the 90th percentile in men (BMI = 28.69) and an inverse U-shaped relationship at the 30th percentile of BMI in women (BMI = 21.37). Conclusions Quantile regression can provide information that may be masked by OLS in analyzing the relationship between sleep duration and BMI. Sleep modification with the aim to obtain the optimal sleep duration may help to reduce BMI in obese men. © Swiss School of Public Health 2011.


Wu C.-L.,National Chung Hsing University | Chang C.-M.,Institute of Athletics | Hung W.,Sport Science Research Center | Fang S.-H.,Institute of Athletics | Chang C.-K.,Sport Science Research Center
Journal of the International Society of Sports Nutrition | Year: 2011

Many athletes need to participate in multiple events in a single day. The efficient post-exercise glycogen recovery may be critical for the performance in subsequent exercise. This study examined whether post-exercise carbohydrate supplementation could restore the performance in the subsequent simulated wrestling match. The effect of branched-chain amino acids and arginine on glucose disposal and performance was also investigated. Nine well-trained male wrestlers participated in 3 trials in a random order. Each trial contained 3 matches with a 1-hr rest between match 1 and 2, and a 2-hr rest between match 2 and 3. Each match contained 3 exercise periods interspersed with 1-min rests. The subjects alternated 10-s all-out sprints and 20-s rests in each exercise period. At the end of match 2, 3 different supplementations were consumed: 1.2 g/kg glucose (CHO trial), 1 g/kg glucose + 0.1 g/kg Arg + 0.1 g/kg BCAA (CHO+AA trial), or water (placebo trial). The peak and average power in the 3 matches was similar in the 3 trials. After the supplementation, CHO and CHO+AA trial showed significantly higher glucose and insulin, and lower glycerol and non-esterified fatty acid concentrations than the placebo trial. There was no significant difference in these biochemical parameters between the CHO and CHO+AA trials. Supplementation of carbohydrate with or without BCAA and arginine during the post-match period had no effect on the performance in the following simulated match in wrestlers. In addition, BCAA and arginine did not provide additional insulinemic effect. © 2011 Jang et al; licensee BioMed Central Ltd.


Wu C.-L.,National Chung Hsing University | Shih M.-C.,China Medical University at Taichung | Chang C.-K.,Sport Science Research Center
Journal of the International Society of Sports Nutrition | Year: 2010

The supplementation of sodium bicarbonate (NaHCO3) could increase performance or delay fatigue in intermittent high-intensity exercise. Prolonged tennis matches result in fatigue, which impairs skilled performance. The aim of this study was to investigate the effect of NaHCO3supplementation on skilled tennis performance after a simulated match. Nine male college tennis players were recruited for this randomized cross-over, placebo-controlled, double-blind study. The participants consumed NaHCO3(0.3 g. kg-1) or NaCl (0.209 g. kg-1) before the trial. An additional supplementation of 0.1 g. kg-1NaHCO3or 0.07 g. kg-1NaCl was ingested after the third game in the simulated match. The Loughborough Tennis Skill Test was performed before and after the simulated match. Post-match [HCO3 -] and base excess were significantly higher in the bicarbonate trial than those in the placebo trial. Blood [lactate] was significantly increased in the placebo (pre: 1.22 ± 0.54; post: 2.17 ± 1.46 mM) and bicarbonate (pre: 1.23 ± 0.41; post: 3.21 ± 1.89 mM) trials. The match-induced change in blood [lactate] was significantly higher in the bicarbonate trial. Blood pH remained unchanged in the placebo trial (pre: 7.37 ± 0.32; post: 7.37 ± 0.14) but was significantly increased in the bicarbonate trial (pre: 7.37 ± 0.26; post: 7.45 ± 0.63), indicating a more alkaline environment. The service and forehand ground stroke consistency scores were declined significantly after the simulated match in the placebo trial, while they were maintained in the bicarbonate trial. The match-induced declines in the consistency scores were significantly larger in the placebo trial than those in the bicarbonate trial. This study suggested that NaHCO3supplementation could prevent the decline in skilled tennis performance after a simulated match. © 2010 Wu et al; licensee BioMed Central Ltd.


Chao J.-J.,National Pingtung University of Science and Technology | Chuang C.-L.,Jen Ai Hospital | Lu H.-K.,Sport Science Research Center | Wu M.-C.,National Pingtung University of Science and Technology | Hsieh K.-C.,Charder Electronic Co.
Scientific Research and Essays | Year: 2011

To establish the appropriate predictive equations of body segments by bioelectrical impedance analysis (BIA) in Taiwan elite male football players, 26 disciplined players at first grade in collegiate league have been recruited in this study. The measurement data by our newly developed predictive equation was compared with Tanita BC-418 to confirm the greater performance in prediction of body composition in our equation. The actual analyzed data of segments body composition by dual-energy X-ray absorptiometry (DXA) was taken as reference one. Both of the correlation coefficients of whole body fat free mass (FFM) measured by DXA between BC-418 as well as that of our newly developed predictive equation were over 0.95. However, the correlation coefficients of upper limb, lower limb and truck FFM measured by predictive equation highly correlated to that of the reference DXA were 0.75, 0.76 and 0.89, respectively. They all were better than that of BC-418 measurement. In summary, the greater performance in prediction of segments body composition in our developed predictive equation by BIA measurement has shown the possibility of application for monitoring athlete body composition especially the limb and trunk. © 2011 Academic Journals.


Hsieh L.-C.,Kaohsiung Municipal United Hospital | Chow C.-J.,National Kaohsiung Marine University | Chang W.-C.,Kaohsiung Municipal United Hospital | Liu T.-H.,Taipei Physical Education College | Chang C.-K.,Sport Science Research Center
Asia Pacific Journal of Clinical Nutrition | Year: 2010

Malnutrition and muscle loss are common in bed-ridden elderly nursing home residents. Supplementation of β-hydroxy-β-methylbutyrate (HMB) has been shown to prevent muscle loss in several catabolic conditions. The aim of this study was to investigate the effect of HMB supplementation on body composition and protein metabolism in bed-ridden elderly nursing home residents receiving tube feeding. The subjects were randomly assigned to HMB (n=39, 2 g/d) or control group (n=40). Anthropometry measurements, blood sampling, and 24-hr urine collection were performed on the day before and 14 days after the start of the study. A subgroup of subjects (HMB: n=19, control: n=20) continued the study for another 14 days. Changes in body weight and BMI were not significantly different between the groups after 14 or 28 days after controlling for baseline BMI. Blood urea nitrogen significantly decreased in the HMB group, while it remained unchanged in the control group after 14 days. Urinary urea nitrogen excretion significantly decreased in the HMB group, while it showed a trend of increase in the control group after 14 and 28 days, respectively. Changes in blood urea nitrogen and urinary urea nitrogen excretion were significantly different between the groups after controlling for baseline BMI. This study suggested that HMB supplementation for 2-4 weeks could reduce muscle breakdown in bed-ridden elderly nursing home residents receiving tube feeding.


Tsai M.-L.,Institute of Athletics | Li T.-L.,National Taiwan Sport University | Chou L.-W.,China Medical University at Taichung | Chang C.-K.,Sport Science Research Center | And 2 more authors.
Journal of Strength and Conditioning Research | Year: 2012

The aim of this study was to investigate the cumulative effects of intensive resistance training on salivary immunoglobulin A (SIgA) and cortisol responses in elite male weightlifters. Eleven elite male Taiwanese weightlifters were trained through 3 training stages before a national weightlifting competition, and this was followed by a 2-week recovery stage. Resting saliva samples were collected once in each of the 4 stages. Salivary concentrations of total protein (TP), SIgA, lactoferrin, and cortisol were measured. The results showed that (a) salivary TP concentrations were not significantly affected; (b) resting levels of SIgA, the ratio of SIgA to TP (SIgA/TP), cortisol, and the ratio of cortisol to TP (cortisol/TP) were significantly higher in the training stages than in the recovery stage; (c) a positive correlation was revealed between the ratios of SIgA/TP and cortisol/TP; and (d) the resting salivary lactoferrin concentrations and the ratio of lactoferrin to TP (lactoferrin/TP) were significantly lower in stage 1 than in the recovery stage. The findings in this study suggest that prolonged, intensive resistance training exerts cumulative effects on SIgA and cortisol responses in elite weightlifters. © 2012 National Strength and Conditioning Association.


Ahmadizad S.,Shahid Beheshti University | Bassami M.,Sport Science Research Center
Clinical Hemorheology and Microcirculation | Year: 2010

The purpose of this study was to investigate the effects of time of day on responses of the main determinants of blood rheology to acute endurance exercise. Ten healthy male subjects (age, 26.9±5.5 yr) performed two bouts of running at 65% of VO2peak for 45min on a motorised treadmill in the morning (08:00h) and evening (20:00h), which were followed by 30 min recovery. The two exercise trials were performed in two separate days with 7 days intervening. Haemorheological variables were measured before, immediately after exercise and after recovery. Haematocrit, haemoglobin and RBC count were increased significantly (p < 0.01) after 45min running in both morning and evening trials and normalised following recovery, irrespective of time of day. Plasma viscosity increased significantly (F2,18 = 12.4, p < 0.01) following sub-maximal exercise in both trials and returned to pre-exercise level at the end of recovery. Baseline values (p < 0.05) but not responses of plasma viscosity to exercise were significantly affected by time of day. Neither a significant main effect of exercise nor a significant (p > 0.05) time-of-day effect was found for plasma proteins. It was concluded that sub-maximal running at 08:00 or 20:00 h does not induce different responses in the main determinant of blood rheology. © 2010 - IOS Press and the authors. All rights reserved.


Negahban H.,Ahvaz Jundishapur University of Medical Sciences | Etemadi M.,Ahvaz Jundishapur University of Medical Sciences | Naghibi S.,Sport Science Research Center | Emrani A.,Tehran University of Medical Sciences | And 3 more authors.
Gait and Posture | Year: 2013

The aim was to examine the effects of muscle fatigue of knee extensor and hip abductor muscles on dynamic standing balance of patients with patellofemoral pain syndrome (PFPS) compared to their healthy matched controls. Thirty participants (15 with PFPS, 15 controls) were recruited. Isolated muscle fatigue of two muscles was induced isokinetically in three separate sessions (one practice and two testing sessions) with a rest interval of at least 72. h. In each testing session, fatigue protocol of only one muscle group was performed for the both legs with a rest time of 30. min. After determining peak torque, participants were encouraged to perform continuous maximal concentric-eccentric contraction of the target muscle until the torque output dropped below 50% of peak value for 3 consecutive repetitions. Immediately after the completion of the fatigue protocol, balance testing of participants was undertaken during single leg standing using the Biodex stability system. Balance stability measures included the overall, anteroposterior and mediolateral stability indices (OSI, APSI and MLSI, respectively). Patients exhibited decreased balance stability in the sagittal plane (higher APSI) when compared to controls. Isolated muscle fatigue of the knee extensors and hip abductors reduced balance stability in both study groups. Fatigue of hip abductors was associated with greater balance instability (higher OSI and APSI) than fatigue of knee extensors. © 2012 Elsevier B.V.

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