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Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an average of 1.83% (SD = 0.96; p less than 0.05). This improvement was inversely related to an increase in maximal voluntary contraction torque (r = -0.89, p less than 0.05) and poorly correlated with changes in the contractile kinetics of the quadriceps muscle (r range from 0.36 to -0.46). These findings suggest that sprint performance is poorly predicted by muscle intrinsic properties and that a neural adaptation appears to explain most of the observed functional adaptations. (Contains 2 tables and 1 figure.)

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Copyright of Transformations in Business & Economics is the property of Vilnius University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

The article presents a study that attempts to establish the dynamics of maximal voluntary contraction force, height of drop jump and electrically evoked quadriceps muscle force at different stimulation frequencies during and after stretch-shortening exercise (SSE). In this study, healthy untrained men were participated. The research concluded that the time-course of voluntary and electrically evoked muscle performance during and after SSE is different.

Abstract: Healthy untrained men (age 20.4±1.7years, n =20) volunteered to participate in an experiment in order to establish dynamics of indirect symptoms of skeletal muscle damage (ISMD) (decrease in maximal isometric voluntary contraction torque (MVCT) and torque evoked by electrostimulation at different frequencies and at different quadriceps muscle length, height (H) of drop jump (DJ), muscle soreness and creatine kinase (CK) activity in the blood) after 100 DJs from 0.75m height performed with maximal intensity with an interval of 20s between the jumps (stretch-shortening exercise, SSE). All ISMDs remained even 72h after SSE (P <0.01–0.001). The muscle experienced greater decrease (P <0.01) in torque evoked by electrostimulation (at low stimulation frequencies and at short muscle length in particular) after SSE than neuromuscular performance (MVCT and H of DJ) which demonstrated secondary decrease (P <0.01) in neuromuscular performance during the first 48h after SSE. Within 24–72h after the SSE the subjects felt an acute muscle pain (5–7 points approximately) and the CK activity in the blood was significantly increased up to 1200 IU/L (P <0.001). A significant correlation between decrease in MVCT and H of DJ 24–48h after SSE on the one hand and muscle soreness registered within 24–48h after SSE on the other was observed, whereas correlation between the other indirect symptoms of skeletal muscle damage was not significant. [Copyright &y& Elsevier]