Energy Metabolism and Fatigue in Human Skeletal Muscle During Maximal Exercise and Recovery with Special Reference to Type I and II Fibres PDF Download

Author: Anna Casey
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Anna Casey
Publisher:
ISBN:
Category :
Languages : en
Pages : 121

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Author: Craig Williams
Publisher: Routledge
ISBN: 1134053517
Category : Science
Languages : en
Pages : 529

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Book Description
When human muscle fatigues, athletic performance becomes impaired. For those individuals suffering muscle or metabolic diseases the effects of muscle fatigue can make everyday tasks difficult. Understanding the scientific processes responsible for skeletal muscle fatigue is therefore central to the study of the physiology of sport, exercise and health. Written by a team of leading international exercise scientists, this book explores the mechanisms of muscle fatigue and presents a comprehensive survey of current research on this important topic. Examining the wide variety of protocols, assessment methods and exercise models used to study muscle fatigue, the book explores the differential effects of fatigue as influenced by: age gender fitness and training the use of ergogenic aids medical conditions including cerebral palsy, muscular dystrophy and glycogenosis. Human Muscle Fatigue covers both clinical and applied approaches in sport and exercise physiology and devotes an entire section to the conceptual framework underpinning research in this area, helping readers from a wide range of backgrounds to engage with the topic. Accessible and detailed, this book is a key text for students and practitioners working in exercise and sports science, medicine, physical therapy and health.

Author: Karin Söderlund
Publisher:
ISBN:
Category :
Languages : en
Pages : 50

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Author: Ruth Porter
Publisher: John Wiley & Sons
ISBN: 047071512X
Category : Medical
Languages : en
Pages : 432

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The Novartis Foundation Series is a popular collection of the proceedings from Novartis Foundation Symposia, in which groups of leading scientists from a range of topics across biology, chemistry and medicine assembled to present papers and discuss results. The Novartis Foundation, originally known as the Ciba Foundation, is well known to scientists and clinicians around the world.

Author: Mark Hargreaves
Publisher: Human Kinetics
ISBN: 9780736041034
Category : Energy metabolism
Languages : en
Pages : 320

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A comprehensive reference for biochemists, sport nutritionists, exercise physiologists, and graduate students in those disciplines. Provides information on the metabolic processes that take place during exercise, examining in depth the mobilization and utilization of substrates during physical activity. Focuses primarily on the skeletal muscle, but also discusses the roles of the liver and adipose tissue. Annotation copyright by Book News, Inc., Portland, OR

Author: Pierre Marconnet
Publisher: S. Karger AG (Switzerland)
ISBN:
Category : Medical
Languages : en
Pages : 260

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Author: Stuart R. Gray
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Increasing the temperature of the exercising muscle, passively or actively, leads to alterations in the contractile properties of the muscle, importantly an increase in power output. There is limited information, however, regarding the metabolic changes, if any, occurring within the muscle at higher temperatures and how these are related to the contractile changes occurring within the muscle and how such changes may, or may not, affect the efficiency of the working muscles. The greater power output produced during maximal sprint cycling, after a passive increase in Tm, was associated with an increase in the rate of anaerobic ATP turnover and muscle fibre conduction velocity. Further investigation revealed that this greater anaerobic ATP turnover within the muscle was the result of a greater activity of type HA fibres in the cadence range of 160-180 revs. min−1. When the external power output of the muscle remains constant during more prolonged cycling exercise, performed at 60 revs. min−1, there was also a greater rate of anaerobic ATP turnover in the first 2 min of exercise, with no differences in the remainder of exercise after passive elevation of Tm. There were no differences in the aerobic energy contribution or the kinetics of the V02 response between T. conditions. These changes led to a decrease in mechanical efficiency in the first 2 min of exercise, which was associated with a tendency for a greater PCr degradation in type I fibres. When T. was elevated via prior intense exercise there was decrease in mechanical efficiency, during 6 min of heavy exercise, at both 60 and 120 revs. min−1. There was also a greater "absolute" primary amplitude and decrease in the slow component after prior exercise, with the response being greater at 120 revs. min−1. The present research has demonstrated that whilst an increase in T. leads to a greater power output, during maximal exercise, mechanical efficiency is reduced as exercise progresses beyond a few seconds. Furthermore, at faster pedal rates T. affects type IIA fibres whilst at slower pedal rates (60 revs. min−1) there appears to be a preferential effect on type I fibres, highlighting the velocity specific effect of Tm.

Author: Aurora Foster
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Skeletal muscle fatigue is the contraction-induced decline in whole muscle force or power, and can be greater in older versus young adults. Fatigue primarily results from increased metabolism elevating phosphate (Pi) and hydrogen (H+), which alters myosin-actin interactions; however, which steps of the myosin-actin cross-bridge cycle are changed and their reversibility are unclear. PURPOSE: This study sought to: 1) Examine the effects of elevated Pi and H+ on molecular and cellular function, and 2) Test the ability of deoxyadenosine triphosphate (dATP), an alternative energy to adenosine triphosphate (ATP), to reverse the contractile changes induced with high Pi and H+. METHODS: Maximal tension (force/cross-sectional area), myofilament mechanics and myosin-actin cross-bridge kinetics were measured in 214 single fibers (104 type 1) from the vastus lateralis of eight (4 men) healthy, sedentary older adults (71±1.3 years) under normal (5 mM Pi, pH 7.0), simulated fatigue (30 mM Pi, pH 6.2) and simulated fatigue with dATP conditions. RESULTS: Tension declined with high Pi and H+ in slow- (type I, 23%) and fast-contracting (type II, 28%) fibers due to fewer strongly bound myosin heads (28-48%) and slower cross-bridge kinetics (longer myosin attachment times (ton) (18-40%) and reduced rates of force production (18-30%)). Type I myofilaments became stiffer with high Pi and H+ (48%), which may have partially mitigated fatigue-induced tension reduction. Elevated Pi and H+ with dATP moderately improved force production similarly in both fiber types (8-11%) compared to high Pi and H+ with ATP. In type I fibers, high Pi and H+ with dATP returned the number of myosin heads strongly bound and ton to normal, while the rate of force production became faster than normal (16%). In type II fibers, high Pi and H+ with dATP did not change the number of myosin heads bound, but cross-bridge kinetics were 16-23% faster than normal. CONCLUSION: These results identified novel fiber-type specific changes in myosin-actin cross-bridge kinetics and myofilament stiffness that help explain fatigue-related force reduction in human single skeletal muscle fibers as well as an alternative energy source that partially to fully reverses contractile changes of elevated Pi and H+ that occur with fatigue.

Author: Francis D. Carlson
Publisher: Prentice Hall
ISBN:
Category : Science
Languages : en
Pages : 184

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