TY - JOUR
T1 - Contralateral effects of unilateral strength and skill training
T2 - Modified Delphi consensus to establish key aspects of cross-education
AU - Manca, A.
AU - Hortobágyi, T.
AU - Carroll, T. J.
AU - Enoka, R. M.
AU - Farthing, J. P.
AU - Gandevia, S. C.
AU - Kidgell, D. J.
AU - Taylor, J. L.
AU - Deriu, F.
N1 - Funding Information:
Open access funding provided by Università degli Studi di Sassari within the CRUI-CARE Agreement. No funding was received for the performance of this work.
Funding Information:
The authors are indebted to each of the experts who kindly completed the two-round survey: Justin W. Andrushko, Trevor S. Barss, David G. Behm, Timothy J. Carroll, Franca Deriu, Ron L. Diercks, Monika Ehrensberger, Roger M. Enoka, Jonathan P. Farthing, Ashlyn K. Frazer, David A. Gabriel, Simon C. Gandevia, Stuart Goodall, Ashlee M. Hendy, Frances Horgan, Glyn Howatson, Dawson J. Kidgell, Christopher Latella, Nicola A. Maffiuletti, Andrea Manca, Gonzalo Marqu?z, Joel Mason, Kenneth Monaghan, Joanne Munn, Alan J. Pearce, Daniel Simpson, Janet L. Taylor, Azusa Uematsu, Menno Veldman, Shi Zhou, Inge Zijdewind, and Tjerk Zult
Publisher Copyright:
© 2020, The Author(s).
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/1
Y1 - 2021/1
N2 - Background: Cross-education refers to increased motor output (i.e., force generation, skill) of the opposite, untrained limb following a period of unilateral exercise training. Despite extensive research, several aspects of the transfer phenomenon remain controversial. Methods: A modified two-round Delphi online survey was conducted among international experts to reach consensus on terminology, methodology, mechanisms of action, and translational potential of cross-education, and to provide a framework for future research. Results: Through purposive sampling of the literature, we identified 56 noted experts in the field, of whom 32 completed the survey, and reached consensus (75% threshold) on 17 out of 27 items. Conclusion: Our consensus-based recommendations for future studies are that (1) the term ‘cross-education’ should be adopted to refer to the transfer phenomenon, also specifying if transfer of strength or skill is meant; (2) functional magnetic resonance imaging, short-interval intracortical inhibition and interhemispheric inhibition appear to be promising tools to study the mechanisms of transfer; (3) strategies which maximize cross-education, such as high-intensity training, eccentric contractions, and mirror illusion, seem worth being included in the intervention plan; (4) study protocols should be designed to include at least 13–18 sessions or 4–6 weeks to produce functionally meaningful transfer of strength, and (5) cross-education could be considered as an adjuvant treatment particularly for unilateral orthopedic conditions and sports injuries. Additionally, a clear gap in views emerged between the research field and the purely clinical field. The present consensus statement clarifies relevant aspects of cross-education including neurophysiological, neuroanatomical, and methodological characteristics of the transfer phenomenon, and provides guidance on how to improve the quality and usability of future cross-education studies.
AB - Background: Cross-education refers to increased motor output (i.e., force generation, skill) of the opposite, untrained limb following a period of unilateral exercise training. Despite extensive research, several aspects of the transfer phenomenon remain controversial. Methods: A modified two-round Delphi online survey was conducted among international experts to reach consensus on terminology, methodology, mechanisms of action, and translational potential of cross-education, and to provide a framework for future research. Results: Through purposive sampling of the literature, we identified 56 noted experts in the field, of whom 32 completed the survey, and reached consensus (75% threshold) on 17 out of 27 items. Conclusion: Our consensus-based recommendations for future studies are that (1) the term ‘cross-education’ should be adopted to refer to the transfer phenomenon, also specifying if transfer of strength or skill is meant; (2) functional magnetic resonance imaging, short-interval intracortical inhibition and interhemispheric inhibition appear to be promising tools to study the mechanisms of transfer; (3) strategies which maximize cross-education, such as high-intensity training, eccentric contractions, and mirror illusion, seem worth being included in the intervention plan; (4) study protocols should be designed to include at least 13–18 sessions or 4–6 weeks to produce functionally meaningful transfer of strength, and (5) cross-education could be considered as an adjuvant treatment particularly for unilateral orthopedic conditions and sports injuries. Additionally, a clear gap in views emerged between the research field and the purely clinical field. The present consensus statement clarifies relevant aspects of cross-education including neurophysiological, neuroanatomical, and methodological characteristics of the transfer phenomenon, and provides guidance on how to improve the quality and usability of future cross-education studies.
KW - Cross-education
UR - http://www.scopus.com/inward/record.url?scp=85096004015&partnerID=8YFLogxK
U2 - 10.1007/s40279-020-01377-7
DO - 10.1007/s40279-020-01377-7
M3 - Article
C2 - 33175329
AN - SCOPUS:85096004015
SN - 0112-1642
VL - 51
SP - 11
EP - 20
JO - Sports Medicine
JF - Sports Medicine
IS - 1
ER -