EVIDENCE OF HOMOLOGOUS AND HETEROLOGOUS EFFECTS AFTER UNILATERAL LEG TRAINING IN YOUTH

The positive effects of unilateral training on contralateral muscles (cross education) has been demonstrated with adults for over a century. There is limited evidence for cross education of heterologous muscles. Cross education has not been demonstrated with children. It was the objective of this study to investigate cross education training in children examining ipsilateral and contralateral homologous and heterologous muscles. Forty-eight male children (10-13 years) were assessed for unilateral, ipsilateral and contralateral lower limb strength, power and endurance (1 repetition maximum (RM) leg press, knee extensors (KE) and flexors (KF) maximum voluntary isometric contractions (MVIC), countermovement jump (CMJ), muscle endurance test (leg press repetitions with 60% 1RM)), and upper body unilateral MVIC elbow flexors (EF) and handgrip strength. An eight-week training program involved two unilateral leg press resistance training groups (high load-low repetitions: 4-8 sets of 5RM, and low load-high repetitions:1-2 sets of 20RM) and control (untrained) group. All muscles exhibited improvements of 6.1% to 89.1%. The trained limb exhibited greater adaptations than the untrained limb for leg press 1RM (40.3% vs. 25.2%; p=0.005), and 60% 1RM leg press (104.1% vs. 73.4%; p=0.0001). The high load-low repetition training induced (pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author