Info Neural Adaptations To Resistive Exercise: Mechanisms As Well As Recommendations For Preparation Practices
Gabriel DA1, Kamen G, Frost G.
Sports Med. 2006;36(2):133-49.
Abstract
It is to a greater extent than oftentimes than non accepted that neural factors play an of import role inward musculus strength gains. This article reviews the neural adaptations inward strength, amongst the finish of laying the foundations for practical applications inward sports medicine as well as rehabilitation. An increment inward muscular strength without noticeable hypertrophy is the commencement trouble of prove for neural interest inward acquisition of muscular strength. The work of surface electromyographic (SEMG) techniques let on that strength gains inward the early on stage of a preparation regimen are associated amongst an increment inward the aAmplitude of SEMG activity. This has been interpreted equally an increment inward neural drive, which denotes the magnitude of efferent neural output from the CNS to active musculus fibres. However, SEMG activity is a global mensurate of musculus activity. Underlying alterations inward SEMG activity are changes inward motor unit of measurement firing patterns equally measured past times indwelling (wire or needle) electrodes. Some studies lead hold reported a transient increment inward motor unit of measurement firing rate. Training-related increases inward the charge per unit of measurement of tension evolution lead hold too been linked amongst an increased probability of doublet firing inward private motor units. H5N1 doublet is a really curt interspike interval inward a motor unit of measurement train, as well as ordinarily occurs at the onslaught of a muscular contraction. Motor unit of measurement synchronisation is unopen to other possible machinery for increases inward musculus strength, but has withal to hold out definitely demonstrated. There are several lines of prove for primal command of training-related adaptation to resistive exercise. Mental practise using imagined contractions has been shown to increment the excitability of the cortical areas involved inward motion as well as displace planning. However, preparation using imagined contractions is unlikely to hold out equally effective equally physical training, as well as it may hold out to a greater extent than applicable to rehabilitation. Retention of strength gains after dissipation of physiological effects demonstrates a rigid practise effect. Bilateral contractions are associated amongst lower SEMG as well as strength compared amongst unilateral contractions of the same musculus group. SEMG magnitude is lower for eccentric contractions than for concentric contractions.
However, resistive preparation tin displace contrary these trends. The final trouble of prove presented involves the notion that unilateral resistive exercise of a specific limb volition too final result inward preparation effects inward the unexercised contralateral limb (cross-transfer or cross-education). Peripheral interest inward training-related strength increases is much to a greater extent than uncertain. Changes inward the sensory receptors (i.e. Golgi tendon organs) may Pb to disinhibition as well as an increased facial expression of muscular force. Agonist musculus activity results inward limb motion inward the desired direction, piece antagonist activity opposes that motion. Both decreases as well as increases inward co-activation of the antagonist lead hold been demonstrated. H5N1 reduction inward antagonist co-activation would allow increased facial expression of agonist musculus force, piece an increment inward antagonist co-activation is of import for maintaining the integrity of the joint. Thus far, it is non clear what the CNS volition optimise: forcefulness production or articulation integrity. The next recommendations are made past times the authors based on the existing literature. Motor learning theory as well as imagined contractions should hold out incorporated into strength-training practice. Static contractions at greater musculus lengths volition transfer across to a greater extent than articulation angles. Submaximal eccentric contractions should hold out used when at that topographic point are issues of musculus pain, detraining or limb immobilisation. The reversal of antagonists (antagonist-to-agonist) proprioceptive neuromuscular facilitation contraction designing would hold out useful to increment the charge per unit of measurement of tension evolution inward older adults, thence serving equally an of import rubber inward preventing falls. When evaluating the neural changes induced past times strength preparation using EMG recording, antagonist EMG activity should e'er hold out measured as well as evaluated.
PMID: 16464122 [PubMed - indexed for MEDLINE]