TY  - JOUR
A1  - Henschke, Jakob
A1  - Zecher, Mahli Megan
A1  - Mayer, Frank
A1  - Engel, Tilman
T1  - Contralateral repeated bout effect following preconditioning exercises
T2  - Sport sciences for health
N2  - Background Recent studies indicate the existence of a repeated bout effect on the contralateral untrained limb following eccentric and isometric contractions. Aims This review aims to summarize the evidence for magnitude, duration and differences of this effect following isometric and eccentric preconditioning exercises. Methods Medline, Cochrane, and Web of science were searched from January 1971 until September 2020. Randomized controlled trials, case-control studies and cross-sectional studies were identified by combining keywords and synonyms (e.g., "contralateral", "exercise", "preconditioning", "protective effect"). At least two of the following outcome parameters were mandatory for study inclusion: strength, muscle soreness, muscle swelling, limb circumference, inflammatory blood markers or protective index (relative change of aforementioned measures). Results After identifying 1979 articles, 13 studies were included. Most investigations examined elbow flexors and utilized eccentric isokinetic protocols to induce the contralateral repeated bout effect. The magnitude of protection was observed in four studies, smaller values of the contralateral when compared to the ipsilateral repeated bout effect were noted in three studies. The potential mechanism is thought to be of neural central nature since no differences in peripheral muscle activity were observed. Time course was examined in three investigations. One study showed a smaller protective effect following isometric preconditioning when compared to eccentric preconditioning exercises. Conclusions The contralateral repeated bout effect demonstrates a smaller magnitude and lasts shorter than the ipsilateral repeated bout effect. Future research should incorporate long-term controlled trials including larger populations to identify central mechanisms. This knowledge should be used in clinical practice to prepare immobilized limbs prospectively for an incremental load.
KW  - musculoskeletal physiological phenomena
KW  - muscle damage
KW  - adaptation
KW  - Crossover
KW  - muscle soreness
KW  - isometric contraction
Y1  - 2021
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/58419
SN  - 1824-7490
SN  - 1825-1234
VL  - 18
IS  - 1
SP  - 1
EP  - 10
PB  - Soringer Italia
CY  - Milan
ER  -