Neuromuscular Adaptations To Training
Neuromuscular Adaptations toTrainingBaechle Chapter 4, pp. 143-151,Powers & Howley pp. 253-255
Lecture Overview Neural AdaptationsSkeletal Muscle AdaptationsConnective Tissue AnatomyConnective Tissue Adaptations
Key Concepts of PhysiologyAdaptations to Exercise Training Each person responds differently to each trainingprogram. The magnitude of the physiological or performancegain is related to the size of an athlete’s adaptationalwindow. The amount of physiological adaptation depends onthe effectiveness of the exercise prescriptions usedin the training program. Training for peak athletic performance is differentfrom training for optimal health and fitness. There is a psychological component to training.
Neural Adaptations Increases in strength due to short term(eight to twenty weeks) training are theresult of neural adaptations.Neural adaptations can include improvedsynchronization of motor unit firing andimproved ability to recruit motor units toenable a person to match the strengthelicited by electrical stimulation.
“Size Principle”With heavy resistance training, all muscle fibers get bigger becausethey are all recruited in consecutive order by their size to producehigh levels of force. In advanced lifters, the central nervous systemmight adapt by allowing these athletes to recruit some motor unitsnot in consecutive order, but by recruiting larger ones first to helpwith greater production of power or speed in a movement.
Recruiting Order
Type of Training Adaptations to resistance training are specific to the typeof exercise performed. Moreover, resistance training hasno meaningful impact on aerobic power. Although aerobic endurance training increases aerobicpower, it does not enhance muscle strength or size. Infact, intense aerobic endurance training can actuallycompromise the benefits of resistance training.
Stimulating Muscular Adaptationsthrough Resistance Training For Strength For Muscle Size High loads, few repetitions, full recoveryperiods.Moderate loads, high volume, short tomoderate rest periods.For Muscular Endurance Low intensity, high volume, little recoveryallowed.
Skeletal Muscle nce trainingSize of musclefibersIncreaseNo changeNumber of musclefibersNo changeNo changeMovement speedIncreaseNo changeStrengthIncreaseNo changeAerobic capacityNo changeIncreaseAnaerobic capacityIncreaseNo change
Skeletal Muscle AdaptationsVariableResults followingresistance trainingResults following aerobicendurance trainingFiber sizeIncreasesNo change or increasesslightlyCapillary densityNo change or reasesFast heavy-chainmyosinIncreases in amountNo change or decreasesin amountType II musclefiber subtypeconversionAlmost all to Type IIaWith sprint interval, amajority to Type IIaMuscle fibers
Muscle Fiber Size Hypertrophy: The process of hypertrophyinvolves both an increase in the synthesis of thecontractile proteins actin and myosin within themyofibril and an increase in the number ofmyofibrils within a muscle fiber. The newmyofilaments are added to the external layers ofthe myofibril, resulting in an increase in itsdiameter.Hyperplasia: Some studies report that elitebody-builders have more fibers/motor unit thanthe average person.
Alteration of Muscle Fiber Types Both endurance and resistance exercisetraining have been shown to promote afast-to-slow shift in skeletal muscle fibertypes.However, this shift is often small andgenerally results in a conversion of TypeIIb fibers to Type IIa fibers.
Muscle Fiber Reponses
Neuromuscular Interplay
Responses of Physiological Variables
Collagen Fiber Anatomy
Bone Architecture
Connective Tissue AdaptationsVariableResults followingresistance trainingResults following aerobicendurance trainingConnective tissueLigament strength May increaseIncreasesTendon strengthMay increaseIncreasesCollagen contentMay increaseVariableBone densityNo change or increasesNo change or increases
Adaptations to Tendon Specific changes within a tendon that contributeto the increase in its cross-sectional area andstrength in response to a functional overloadinclude an increase in collagen fibril diameter, a greater number of covalent cross-links within a fiber ofincreased diameter, an increase in the number of collagen fibrils, and an increase in the packing density of collagen fibrils.
Stimulating Connective TissueAdaptations Tendons, Ligaments, Fascia Exercise of low to moderate I does not markedlychange the collagen contentHigh I loading results in a net growth of the involvedtissuesCartilage Weight-bearing forces and complete movementthroughout the range of motion seem tot be essentialto maintaining tissue viability.Moderate aerobic exercise seems adequate forincreasing cartilage thickness. Strenuous exercisedoes not appear to cause degenerative joint disease.
Bone Modeling Forces that reach or exceed a threshold stimulusinitiate new bone formation in the areaexperiencing the mechanical strain.To stimulate bone formation: Use exercises that directly load particular regions ofthe skeletonUse structural exercisesProgressively overload the musculoskeletal system, &progressively increase the load as the tissues becomeaccustomed to the stimulusVary exercise selection, changing the distribution ofthe force vectors to continually present a uniquestimulus for new bone formation
Bone Modeling
Type of Training Adaptations to resistance training are specific to the type of exercise performed. Moreover, resistance training has no meaningful impact on aerobic power. Although aerobic endurance training increases aerobic power, it does not enhance muscle strength or size. In fact, intense aerobic endurance training can actually
18. Adaptations are passed down from parents to their offspring. 19. Birds possess adaptations, such as wings, feathers, and a light skeleton, which enable them to fl y. 20. Plants possess adaptations as well, which enable them to produce food energy from the sun. 21. And alligators possess adaptations which enable them to be strong swimmers 22.
shorter-acting neuromuscular blocking drugs and widespread use of neuromuscular monitoring. 9 Part of this might be related to the recognition that the threshold for complete neuromuscular recovery is a train-of-four ratio of 0.9, instead of the tradit
the neuromuscular function. Muscle strength is reduced during hypothermia, both in the presence and in the absence of neuromuscular blocking drugs. A 2ºC reduction in body temperature may double the duration of neuromuscular blockade. A reduction in muscle strength must be expect
between neuromuscular blocking agents and neuromuscular dys-function acquired in critical illness; limitations include studies with a high risk of bias and a disproportionate contribution from stud-ies examining patients for critical illness polyneuropathy/critical ill-ness
i. Pick a few animal species (examples provided below) to illustrate Sonoran Desert adaptations; include a brief description of characteristics, the animal’s adaptations to its habitat, and adaptations related to migration route, frequency of migration, and reason for migration. ii. E
This lesson was adapted from an animal adaptations lesson created by Kimberly Koopman at Kalaheo High School in Kailua, Hawaii. Many thanks to Hilary Devlin and Megan Chaisson for their contributions to this lesson. Common aquatic animal adaptations: Physical adaptations: - Gills -
Introduction: Different stress factors and plant growth Reactions and adaptations to drought stress Growth forms and morphological adaptations Phenological behaviour Physiological adaptations - Photosynthesis - Transpiration and leaf conductance - Water potential Reactions and adaptations to flood stress
2. AngularJS looks in the template for the ngApp directive which designates our application root. 3. Loads the module associated with the directive. 4. Creates the application injector 5. Compiles the DOM treating the ngApp directive as the root of the compilation AngularJS: beginner's Guide - part 1
