Effects of intense exercise on the physiological and mental condition of female university judoists during a training camp

To clarify the physical and mental fatigue caused by intense exercise and the relationship between the two types of fatigue, we examined changes in anthropometric and biochemical variables, neutrophil function, and the Profile of Mood States (POMS) questionnaire in 13 female university judoists attending a one-week training camp. Blood glucose, total cholesterol, haemoglobin, leukocyte count, IgG, and phagocytic activity all decreased after the training camp compared with baseline (P < or = 0.046). Aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and neutrophil oxidative burst activity increased after the training camp (P < or = 0.007). Of the POMS scores, that for Fatigue increased after the training camp (P = 0.041) and that for Vigour decreased (P = 0.042). The changes in several POMS scores correlated with the changes in blood biochemical variables. In particular, the change in Total mood disturbance was negatively associated with changes in myogenic enzymes (P < or = 0.032). Our results suggest that intense exercise during training camps for female judoists leads to the appearance and accumulation of mental and physical fatigue, which are related to each other.     

LQ preview state feedback with output regulation constraint

This paper addresses the output regulation problem for a class of preview control systems, and derives a state feedback law which suppresses the steady-state error caused by the excitation from polynomial or sinusoidal exogenous inputs. Recently, the output regulation condition for the broader class of distributed parameter systems is characterized via the operator regulator equation. We show that a solution of the operator regulator equation specialized to the preview control system is obtained by solving the matrix regulator equation, and provide the state feedback law which attenuates the transient error optimally with respect to an LQ (Linear Quadratic) performance index.     

Mechanical energy generation and transfer in the racket arm during table tennis topspin backhands

The ability to generate a high racket speed and a large amount of racket kinetic energy on impact is important for table tennis players. The purpose of this study was to understand how mechanical energy is generated and transferred in the racket arm during table tennis backhands. Ten male advanced right-handed table tennis players hit topspin backhands against pre-impact topspin and backspin balls. The joint kinetics at the shoulder, elbow and wrist of the racket arm was determined using inverse dynamics. A majority of the mechanical energy of the racket arm acquired during forward swing (65 and 77% against topspin and backspin, respectively) was due to energy transfer from the trunk. Energy transfer by the shoulder joint force in the vertical direction was the largest contributor to the mechanical energy of the racket arm against both spins and was greater against backspin than against topspin (34 and 28%, respectively). The shoulder joint force directed to the right, which peaked just before impact, transferred additional energy to the racket. Our results suggest that the upward thrust of the shoulder and the late timing of the axial rotation of the upper trunk are important for an effective topspin backhand.