Increased non-oxidative and oxidative ATP production via metabolic pathways in skeletal muscle is essential for the maintenance of force and power production during exercise. However, substrate depletion and accumulation of metabolic byproducts are potential causes of fatigue. Reduced PCr availability can limit power production during sprint exercise, whereas carbohydrate depletion is a major limitation to endurance performance. During sprint exercise increased Pi and H+ may contribute to fatigue, and during prolonged strenuous exercise, the accumulation of NH3, reactive oxygen species, and heat can limit performance. Appropriate training programs and nutritional interventions are potential strategies to enhance fatigue resistance and exercise performance.

Lateral bending of the trunk has been specifically identified as a high risk factor for lower back disorders. However, few studies have presented in vivo kinematic data of the trunk while performing functional lateral bending tasks. Five healthy male subjects performed lateral lifting and lowering tasks under loading condition ranging from light (2kg) to 100% of a maximum (ML) at a controlled velocity. Single lowering tasks were also performed at 125% and 150% of ML. Video based movement analysis was used to determine kinematics of the trunk, pelvis, shoulders and neck in the frontal plane. Centre of pressure (COP) data was also obtained from a force platform on which the subjects stood when performing the lifting and lowering tasks. Kinematics of the trunk revealed a smooth and relatively large change in angular displacement (between 69°to 55°) toward the unloaded side during the lifting phase. Trunk angular displacement significantly decreased with increasing lifting load. The trunk was additionally divided into four segments representing the lower and upper lumbar regions and the lower and upper thoracic regions. The greatest displacement in these segments took place at the upper lumbar and lower thoracic regions (ranging from 29°to 22°and 23°to 17°, respectively) with the least displacement occurring in the lower lumbar and upper thoracic regions (approx. 6° and 5°, respectively). Both the upper lumbar and lower thoracic segments showed significant decreases in angular displacement with increasing load. During the single lowering trials the trunk rotated toward the loaded side with slightly less magnitude to that recorded during the lowering phase of the heaviest lifting and lowering conditions. Angular displacements of the upper lumbar and lower thoracic segments also decreased with increasing load in single lowering. Identified changes in the COP displacement were also correlated to increasing lifting and lowering load. The main findings of this study indicate that it is the central sections of the trunk that have the greatest motion during

Objective To make a survey of medication taken by Chinese athletes and a comparison between Chinese athletes and athletes from other countries in order to get information about how to improve Chinese athletes' performance. Method The information came from the forms"Doping Control Sample Collection" in which athletes answered the question: "What medications have you taken in the past 3 days?" The medicines taken by athletes were classified and statistically analyzed.Results 2,330 athletes and 25 kinds of sports were involved in. Medicines were statistically analyzed with 4 classes: profiling of declaration, vitamins and minerals, medicines for treatments, alternative medicine. Conclusion The survey recorded the types of supplements and medications taken by athletes in China in 1999. Chinese athletes took less vitamins and more alternative medicines than athletes from other countries.

Experimental, clinical and epidemiologic studies have provided strong evidence that physical training has beneficial effects on cardiovascular health. Numerous investigations have demonstrated that exercise increases coronary blood flow and myocardial perfusion. Importantly, training also can stimulate angiogenesis and accelerate collateral vessel growth in animal models with coronary artery occlusion. Cardiac adaptation such as increased vascularity or capillary density has been evidenced after regular endurance exercises. More recently, several studies indicate that physical training induces high levels of myocardial heat shock protein and antioxidant protein expression, which may play an important role in myocardial protection against ischemia-reperfusion injury.

Nitric oxide (NO) plays an important pathophysiological role in osteoarthritis and cartilage metabolism. To determine the relationship between NO and the synthesis of type II collagen in cartilage, we measured levels of type II collagen by ELISA and procollagen (II) mRNA by RT-PCR in cultured lapine chondrocytes that were incubated with some kinds of reagents. 0.2mM sodium nitroprusside (SNP, a NO donor) can release high levels of NO, decreasing type II collagen, suppressing the expression of procollagen (II) mRNA (COL2A1).At the same time, chondrocytes showed a large increase in NO synthesis, a decrease in type II collagen and COL2A1 mRNA in response to 100u/ml IL-1. When 1mg/ml N-nitro-L-arginine methyl easter (NAME, an inhibitor of NO synthase) was mixed with IL-1, NO production was inhibited, the amounts of type II collagen recovered partially and COL2A1 mRNA recovered completely.These data indicate NO can inhibit type II collagen synthesis as IL-1 downstream molecule by suppressing procollagen (II) mRNA.

Objective To observe the articular cartilage injuries complicated with the rupture of anterior cruciate ligament(ACL)in 21 athletes and 43 non-athletes,and investigate the cause and the pattern of cartilage of knee following the ACL rupture in those patients.Methods The pathologic change,location,degree of cartilage lesion were observed. The relationship between the incidence, occurrent time,degree of cartilage injury and ACL rupture,injured degree of cartilage and the course of ACL rupture were studied.Results The incidence of cartilage injury were 75% in all patients, 66.7% in athletes and 79%in non-athletes. Incidence of cartilage injury in non-athletes was significantly higher than that in athletes (P<0.01).Incidence of serious injury of cartilage in the course more than 1 year was significantly higher than that less than 1 year (P<0.01),but there were no statistical difference between the two groups.Conclusion The incidence of articular cartilage injury following ACL rupture were significantly raised in athletes and non-athletes. The longer the ACL ruptured, the more serious the cartilage injured. Results indicated that articular cartilage injuries in the ACL rupture knee were mainly caused by the instability of knee.

20 normal males were examined by BIODEX isokinetic test and rehabilitation system,and data collected were used to observe the influence of angle and time on the isokinetic concentric constriction of knee joint. It was found that angle and time, especially angle factor obviously affected the testing results.

To understand the present situation of sport participation in community residents of Shanghai，study infecting factors to the regular sport participation rate and evaluate recognition degree of the relationship of sport and chronic disease，we carried out questionnaire survey indoors among the permanent residents,aged 35～74,in East Nanjing Road community, including survey on chronic disease and sport participation situation. The material was statistically analyzed and the related factors were proved by x2 test. The results showed that in 1457 permanent residents,470 regularly participat in sport, and were classified as sport population. The prevalence was 32.3%.The gender, age, education level, occupation and chronic disease had statistical significance (P<0.05) and they were probably infecting factors of the regular sport participation rate. Currently,the regular sport participation rate in community is relatively high and the purpose of sport participation was evident, however, the age structure of sport population was imbalance. The sport participation in residents was individualized and without proper scientific instruction.

To study the effect of physical fitness exercise prescription on the cardiac function of collegians, three different exercise prescriptions on the collegians extra-curriculum exercises to develop their strength, cardiac function and overall physical fitness separately and one control were applied. The results show that after 8 weeks training, the rest HR of all exercise groups decreased while SV(stroke volumn), SI (stroke index), CO (cardiac output)and CI (cardiac index) increased significantly. Furthermore, the results also show that VPE (ventricular pumping effectiveness) and VPEI (ventricular pumping effectiveness index) of exercise groups increased while MSP(mean systolic pressure), MDP(mean diastolic pressure) and MAP (mean arterial pressure) decreased at variant degree. From the study it is not difficult to see that doing exercise prescription can develop the collegians' cardiac-function significantly. Comparing these three exercise prescriptions show that doing endurance exercise prescription can get the best effect on developing the cardiac-function, but doing the comprehensive-developing exercise prescription can get more comprehensive effect on cardiac and vascular function. Another result from comparing the control group shows that the females are easier to get the physiological function descent than the males if they do not do exercises actively. In conclusion, it is worth to extend physical fitness exercise prescription in collegians' extra-curriculum exercise because of the simple condition, scientific method and significant effect.

Three hundred and sixty five male senior citizens were divided into experimental group(183 men)and control group(182 men).Exercise in experimental group was carried out with individual prescription for one year and the exercise in control group was in accordance to subjects' habitual interest. The results after 1 year showed that the anthropometric parameters between two groups revealed no significant difference, while the functional parameters were significantly improved in experimental group as compared with that in control group(p＜0.05 or 0.01).It was suggested that for senior citizens, exercise under prescription could significantly improve body function as compared with that without prescription.