Neural Adaptations to Resistance Training

AbstractIt has long been believed that resistance training is accompanied by changes within the nervous system that play an important role in the development of strength. Many elements of the nervous system exhibit the potential for adaptation in response to resistance training, including supraspinal centres, descending neural tracts, spinal circuitry and the motor end plate connections between motoneurons and muscle fibres. Yet the specific sites of adaptation along the neuraxis have seldom been identified experimentally, and much of the evidence for neural adaptations following resistance training remains indirect. As a consequence of this current lack of knowledge, there exists uncertainty regarding the manner in which resistance training impacts upon the control and execution of functional movements. We aim to demonstrate that resistance training is likely to cause adaptations to many neural elements that are involved in the control of movement, and is therefore likely to affect movement execution during a wide range of tasks.We review a small number of experiments that provide evidence that resistance training affects the way in which muscles that have been engaged during training are recruited during related movement tasks. The concepts addressed in this article represent an important new approach to research on the effects of resistance training. They are also of considerable practical importance, since most individuals perform resistance training in the expectation that it will enhance their performance in related functional tasks.

[1]  J. Donoghue,et al.  Learning-induced LTP in neocortex. , 2000, Science.

[2]  D. McCrea Can sense be made of spinal interneuron circuits , 1992 .

[3]  J. Jürimäe,et al.  Cross-sectional and longitudinal uses of isoinertial, isometric, and isokinetic dynamometry. , 1996, Medicine and science in sports and exercise.

[4]  T. Sears,et al.  Short‐term synchronization of intercostal motoneurone activity. , 1976, The Journal of physiology.

[5]  R. Porter,et al.  Corticospinal Function and Voluntary Movement , 1993 .

[6]  J. Semmler,et al.  Motor unit discharge and force tremor in skill- and strength-trained individuals , 1998, Experimental Brain Research.

[7]  T. Jones,et al.  Motor Skills Training Enhances Lesion-Induced Structural Plasticity in the Motor Cortex of Adult Rats , 1999, The Journal of Neuroscience.

[8]  J. Bloedel Functional heterogeneity with structural homogeneity: How does the cerebellum operate? , 1992 .

[9]  J C Rothwell,et al.  Comparison of regional cerebral blood flow with transcranial magnetic stimulation at different forces. , 1996, Journal of applied physiology.

[10]  J. Donoghue,et al.  Strengthening of horizontal cortical connections following skill learning , 1998, Nature Neuroscience.

[11]  Leslie G. Ungerleider,et al.  Functional MRI evidence for adult motor cortex plasticity during motor skill learning , 1995, Nature.

[12]  E. Thorndike,et al.  The influence of improvement in one mental function upon the efficiency of other functions. II. The estimation of magnitudes. , 1901 .

[13]  M Hallett,et al.  Studies of neuroplasticity with transcranial magnetic stimulation. , 1998, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[14]  R M Enoka,et al.  Neural adaptations with chronic physical activity. , 1997, Journal of biomechanics.

[15]  Günter Tidow,et al.  Relative activity of hip and knee extensors in sprinting - implications for training , 1995 .

[16]  R. Carson,et al.  Resistance training enhances the stability of sensorimotor coordination , 2001, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[17]  S. Petersen,et al.  The effects of practice on the functional anatomy of task performance. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[18]  W J Kraemer,et al.  Changes in agonist-antagonist EMG, muscle CSA, and force during strength training in middle-aged and older people. , 1998, Journal of applied physiology.

[19]  S. Cormier,et al.  Transfer of learning: Contemporary research and applications. , 1987 .

[20]  R. D'ambrosia,et al.  Muscular coactivation , 1988, The American journal of sports medicine.

[21]  J. Stephens,et al.  Mirror movements studied in a patient with Klippel‐Feil syndrome. , 1990, The Journal of physiology.

[22]  R. Stein,et al.  Synchronization of human motor units: possible roles of exercise and supraspinal reflexes. , 1975, Electroencephalography and clinical neurophysiology.

[23]  R. Enoka Neural strategies in the control of muscle force , 1997, Muscle & nerve. Supplement.

[24]  E. Fetz,et al.  Neural mechanisms underlying corticospinal and rubrospinal control of limb movements. , 1991, Progress in brain research.

[25]  KM Jacobs,et al.  Reshaping the cortical motor map by unmasking latent intracortical connections , 1991, Science.

[26]  James R. Bloedel,et al.  Coordinate transformation and limb movements: There may be more complexity than meets the eye , 1992, Behavioral and Brain Sciences.

[27]  D. Brooks,et al.  Motor sequence learning: a study with positron emission tomography , 1994, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[28]  M. Kinsbourne Asymmetrical function of the brain , 1978 .

[29]  S. Wise,et al.  Mechanisms of use-dependent plasticity in the human motor cortex. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[30]  G. Margaritondo,et al.  Reactivity of Au with ultrathin Si layers: A photoemission study , 2001 .

[31]  T. Carroll,et al.  Resistance training frequency: strength and myosin heavy chain responses to two and three bouts per week , 1998, European Journal of Applied Physiology and Occupational Physiology.

[32]  S. Farmer,et al.  Central nervous pathways underlying synchronization of human motor unit firing studied during voluntary contractions. , 1991, The Journal of physiology.

[33]  Stephen M. Rao,et al.  The evolution of brain activation during temporal processing , 2001, Nature Neuroscience.

[34]  D. V. von Cramon,et al.  Motor-learning-related changes in piano players and non-musicians revealed by functional magnetic-resonance signals , 1999, Experimental Brain Research.

[35]  D. Costill,et al.  The Effects of Constant External Resistance Exercise and Isokinetic Exercise Training on Work‐induced Hypertrophy , 1988 .

[36]  R. Enoka,et al.  Motor-unit synchronization increases EMG amplitude and decreases force steadiness of simulated contractions. , 2000, Journal of neurophysiology.

[37]  S. Riek,et al.  The influence of joint position on the dynamics of perception-action coupling , 1998, Experimental Brain Research.

[38]  R. Enoka,et al.  Strength training can improve steadiness in persons with essential tremor , 2000, Muscle & nerve.

[39]  B. Timson Evaluation of animal models for the study of exercise-induced muscle enlargement. , 1990, Journal of applied physiology.

[40]  Karl J. Friston,et al.  Motor practice and neurophysiological adaptation in the cerebellum: a positron tomography study , 1992, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[41]  J. R. Rosenberg,et al.  Load-independent contributions from motor-unit synchronization to human physiological tremor. , 1999, Journal of neurophysiology.

[42]  Pa Kirkwood,et al.  SYNAPTIC CONNECTIONS TO INTERCOSTAL MOTONEURONS AS REVEALED BY AVERAGE COMMON EXCITATION POTENTIAL , 1978 .

[43]  J. Adams Historical review and appraisal of research on the learning, retention, and transfer of human motor skills. , 1987 .

[44]  F. Haddad,et al.  highlighted topics Plasticity in Skeletal, Cardiac, and Smooth Muscle Invited Review: Effects of different activity and inactivity paradigms on myosin heavy chain gene expression in striated muscle , 2000 .

[45]  R M Enoka,et al.  Training-related enhancement in the control of motor output in elderly humans. , 1994, Journal of applied physiology.

[46]  D G Sale,et al.  Neural adaptation to resistance training. , 1988, Medicine and science in sports and exercise.

[47]  T. Moritani,et al.  Neural factors versus hypertrophy in the time course of muscle strength gain. , 1979, American journal of physical medicine.

[48]  R. Thayer,et al.  Acute and Chronic Response of Skeletal Muscle to Resistance Exercise , 1994, Sports medicine.

[49]  Masao Ito Mechanisms of motor learning in the cerebellum 1 1 Published on the World Wide Web on 24 November 2000. , 2000, Brain Research.

[50]  K. Häkkinen,et al.  Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in middle-aged and elderly people , 2000, European Journal of Applied Physiology.

[51]  Jing Z. Liu,et al.  Brain activation during human finger extension and flexion movements , 2000, Brain Research.

[52]  R M Enoka,et al.  Strength training improves the steadiness of slow lengthening contractions performed by old adults. , 1999, Journal of applied physiology.

[53]  S. J. Martin,et al.  Cortical plasticity: It's all the range! , 2001, Current Biology.

[54]  J. Rothwell,et al.  Inhibitory action of forearm flexor muscle afferents on corticospinal outputs to antagonist muscles in humans , 1998, The Journal of physiology.

[55]  C. Marsden,et al.  The functions of the basal ganglia and the paradox of stereotaxic surgery in Parkinson's disease. , 1994, Brain : a journal of neurology.

[56]  E Cafarelli,et al.  Adaptations in coactivation after isometric resistance training. , 1992, Journal of applied physiology.

[57]  M. Hallett,et al.  Rapid plasticity of human cortical movement representation induced by practice. , 1998, Journal of neurophysiology.

[58]  D. McCrea Supraspinal and segmental interactions. , 1996, Canadian journal of physiology and pharmacology.

[59]  C. Capaday,et al.  Intracortical connections between motor cortical zones controlling antagonistic muscles in the cat: a combined anatomical and physiological study , 1998, Experimental Brain Research.

[60]  S. Petersen,et al.  Changes in brain activity during motor learning measured with PET: effects of hand of performance and practice. , 1998, Journal of neurophysiology.

[61]  M Swash,et al.  Changes in motor unit synchronization following central nervous lesions in man. , 1993, The Journal of physiology.