The aim of this study was to investigate whether variation in estrogen levels during the menstrual cycle influences susceptibility to exercise-induced muscle damage after stretch-shortening cycle exercise. Physically active women (n = 18; age = 20.2 ± 1.7 yr) participated in this research. The subjects performed one session of 100 maximal drop jumps on day 1 or 2 of the follicular phase and another identical session on day 1 or 2 of the ovulatory phase; the order of the sessions was randomized. Quadriceps femoris muscle peak torque evoked by electrical stimulation and maximal voluntary contraction, muscle pain, and CK activity were measured before and at various times up to 72 h after exercise. It was found that the high estrogen level during the ovulatory phase might be related to an earlier return to baseline muscle strength after strenuous stretch-shortening cycle exercise in that phase compared with the follicular phase. The estrogen effect appears to be highly specific to the damaged site because the differences in most EIMD markers (CK, soreness, and low-frequency fatigue) between the two menstrual cycle phases were small.
This study investigated the role of gender as a potential predictor of health behaviour and potential moderator of the relationship between emotional intelligence and health behaviour. This cross-sectional study included 1214 students (597 males and 617 females). Data were collected using the Schutte Self-Report Inventory and the Health Behaviour Checklist. Stepwise multiple regression analysis was executed with the components of health behaviour as the dependent variables to examine the predictive value of the emotional intelligence indicators as the independent variables. Gender predicted all categories of health behaviours. Only one indicator of emotional intelligence, appraisal, predicted the Accident Control and Traffic Risk Taking categories. The emotional intelligence indicator of social skills emerged only as a predictor of Wellness Maintenance and Enhancement in university students. Gender moderates the relationship between all emotional intelligence indicators and health behaviour components except the relationship between Appraisal and Substance Risk Taking and the relationship between Utilization and traffic risk taking.
The aim of this study was to assess whether side-to-side differences in morphology and function of the upper limbs in 11-12 year-old male baseball players with throwing-related pain (n=14) were more pronounced than that of age-matched healthy untrained subjects (n=16). Baseball players 1) had played baseball≥4.5 h·wk for ≥ 4 years and (2) suffered from moderate-intensity (3-6 points on 10-point questionnaire scale) throwing-related pain in the shoulder or elbow in at least 2 training sessions within the past month. The range of motion (ROM), function and structure of the elbows and shoulders were assessed using goniometry, isokinetic dynamometry and ultrasonography. While the ROM and eccentric external peak torque of internal shoulder rotation were lower, the thickness of the supraspinatus tendon, the ulnar collateral ligament and articular cartilage of the humeral head were larger in baseball players than controls. There were, however, no significant side-to-side differences in any parameter in either group. In conclusion, it is unlikely that side-to-side differences in shoulder and upper limb structure and function contributed to the throwing-related pain in young baseball players, but low shoulder eccentric external peak torque and range of internal rotation may predispose to throwing-related pain.
Objectives: To determine the effect of leg immersion in cold water after stretch-shortening exercise (SSE) on the time-course of indirect indicators of exercise-induced muscle damage (EIMD). Methods: Twenty healthy untrained men twice performed SSE consisting of 100 drop jumps (DJs) from 0.75 m height performed with maximal intensity with an interval of 20 s between the jumps. DJs were performed with counter-movement to 90 degrees angle in the knee and with immediate maximal rebounds. After SSE the subject's legs immediately, as well as after 4 h, 8 h and 24 h, were immersed into a bath filled with water at 15 ± 1 • C. Quadriceps muscle voluntary contraction force (MVCF) and force evoked by electrostimulation (ESF) at different frequencies and at different muscle length, jump height (H), muscle soreness and creatine kinase (CK) activity in the blood were measured before SSE, immediately after SSE and within 72 h of recovery. Results: After stretch-shortening exercise MVCF, ESF and H were significantly (P < 0.001) decreased and were not restored even after 72 h in the group that did not receive the cooling. Within 24-48 h after SSE the subjects felt great muscle pain and CK activity in their blood was increased (P < 0.001). The cooling significantly accelerated the disappearance of all these indicators, except for low-frequency fatigue, but only within 24-72 h after SSE. Conclusion: Cold water immersion after SSE accelerates the disappearance of the majority of indirect indicators of EIMD.
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