Numerous studies on serum enzymes derived from skeletal muscle, such as CH, AST, LDH, are also being reported in the field of sports medicine. In this article, I would like to summarize the findings on “physical exercise and serum enzymes” studied up to the present. Secondly, I will evaluate the usefulness and limits as indicators of condition and muscle fatigue in athletes. The amount of change and time course of Ch, AST, LDH and myoglobin responses were markedly different in 5-km, marathon and triathalon races, and in trained and untrained subjects. Trained subjects showed peaks of these enzymes one day after endurance running, and untrained subjects had a typical biphasic variation after endurance running. The typical change in untrained subjects might reflect a series of different histopathological changes, including muscle damage, repair and regeneration of muscles. In participants of women's marathon races, higher ranking prize winners showed lower levels before and lower increases in Ch activity after the mice than the other participants. higher serum CIA activity above 300 mU/ml accompanied by increases in serum myosin light chain I (MLC I) concentration (above 2.5 ng/ml) without increases in troponin T and CN-MIA were observed during marathon, triathalon, 100-km and 250 km ultra marathon races. The athletes who showed a higher serum CK activity above 500 mU/ml at the pre-race stage felt subjective fatigue and sonic dropped out from the race. Normal persons who had a lower Ch activity below 40.50 mU/ml indi cated lower levels of serum HDL-C and physical fitness (VO2max) . On the contrary, persons who showed a higher CR level of 100-200 mU/ml or more had higher levels of IIDL-C and VO2max. Measurement of serum CK activity might provide useful information for checking health and physical fitness levels in normal persons, and also the physical and subjective conditions of athletes.
The purpose of this study was to investigate the relationship between low back pain (LBP) any physical characteristics in university wrestlers. We especially focused on radiological abnormalitie (RA) in their lumbar regions. Physical characteristics and isokinetic trunk muscle strength of the 55 male university wrestlers were measured. MRI was used to evaluate the cross-sectional areas of trunk muscles between lumbar spine 3 and 4 (L3/4) . Evaluations of LBP were based on the diagnose of orthopedic surgeons and the questionnaire test. According to this evaluation, we assigned all wrestlers into two groups as the LOP group and the no LOP group. Furthermore, four groups were defined by having RA based on X-ray and MRI diagnose. We obtained the following results. In comparison between the LOP group and the no LOP group, the trunk muscle extension flexion strength ratio of the LOP was significantly lower than that of the no LOP group. In addition, the LOP without RA group showed significant low strength of their trunk extensors in comparison with the no LOP without RA group. We considered that the relative low strength of trunk extensors should have some effect on LBP in university wrestlers.
‹Objective› In previous animal studies, it has been observed that ovarian hormones centrally alter baroreflex modulation of cardiovagal nervous control. If this central action of ovarian hormones is observed in human females, non-baroreflex modulation of cardiovagal nervous control should change with the menstrual cycle. The hypothesis in this study was that cardiovagal nervous response to facial cold stimuli (non-baroreflex modulation) changes throughout menstrual cycle.‹Subjects and methods› Eight young healthy women with a normal menstrual cycle participated in this study. The menstrual cycle was divided into 5 phases (menstrual, follicular, ovulatory, early luteal and late luteal) . Resing ECG RR intervals, cardiovagal nervous activity (by heart rate variability), RR intervals and cardiovagal nervous response to facial cold stimuli were measured during each menstrual phase. RR intervals and cardiovagal nervous response to facial cold stimuli were evaluated paying attention to the “quantity” and “quickness” of the changes.‹Results› There were no phase differences in resting RR intervals and cardiovagal nervous activity. Quantity of RR intervals and cardiovagal nervous response and quickness of. RR intervals to facial cold stimuli did not change throughout the menstrual cycle. The speed of cardiovagal nervous response to facial cold accelerated in the follicular phase, and to the contrary, slowed down in the early luteal phase, ‹Conclusion› These data suggest the speed of cardiovagal nervous response mediated non-baroreflex mechanism changes throughout the menstrual cycle.
The purpose of this study was to examine the effect of the different visual and vestibular inputs on EMG response of ankle muscles during movement to absorb impact in sliding down a slope. Thereby, our research focused on the relationship between preactivation (PA) in central program and stretch reflex induced by dorsiflexion immediately after impact. The subjects were nine healthy males. Movements were conducted using a special sliding apparatus. Conditions included sliding down a lower 15°slope with eyes open (Low) and with eyes closed (Low-Closed), and a higher 20°slope with eyes open (High) . PA prior to impact indicated the co-contraction of the medial gastrocnemius (MG) and tibialis anterior (TA) . PA levels in those muscles were significantly higher during High than during Low-Closed (p<0.05) . In contrast, PA of the coleus (Sol) was low in all test conditions. After impact, however, the stretch reflex of Sol during Low-Closed was greater than other test conditions. Because muscle stretch velocities and PA levels of Sol among all test conditions remained unchanged, these results suggest that different visual inputs could change the response of stretch reflex by modulations in reflex gain.
The purpose of this study was to analyze morphological and functional changes in the left ventricular muscle mass and vessel diameters of the arteries in young competitive athletes of various sports and evaluate the correlation between the heart and arterial vessel under the training environment in this latter half of the growth period. The subjects were 51 male college student athletes (mean age, 19.6±0.4 years) of 6 competitive sports (archery, weight lifting, swimming, short-distance races, middle-distance races, and long-distance races) . The diameters of the right and left common carotid arteries, right and left radial arteries, right and left foot dorsal arteries, and the aorta and the left ventricular muscle mass (LVM) were measured by Doppler echocardiography. To minimize the influences of the physique and body weight associated with growth and sport types, all data obtained by measurement were corrected by body surface area. The sum of the diameters of all the above arteries (total arterial diameter : TAD) was obtained to evaluate its correlation with the left ventricular muscle mass. The diameter of the foot dorsal artery was significantly higher in the long-distance runners than in the sprinters (P<0.05) . The diameter of the radial artery according to the 6 types of sport was the highest for weight lifting, followed in order by archery, longdistance races, middle-distance races, swimming, and short-distance races, showing a significant difference between weight lifting and short-distance races (P<0.05 ) . TAD was high for generalized endurance sports and correlated with the left ventricular muscle mass (r=0.893) . Thus, the arterial diameters significantly differed among competitive sports and were particularly increased for endurance exercise. The diameters of the local arteries used for local exercise were also increased. When TAD as a new parameter and its ratio per body surface area were calculated, there was a high correlation between the heart (left ventricular muscle mass) and the arterial diameter. These results suggest that exercise adaptation can he evaluated in the arterial system in svstemic circulation as well as the nervous and muscular systems.