Cross education is modulated by set configuration in knee extension exercise

OBJECTIVES: The main aim of this study was to determine the effects of set configuration during five weeks of unilateral knee extension resistance training on untrained knee extensors performance. METHODS: Thirty-five subjects were randomly assigned to traditional training (TTG; n=14), rest-redistribution (RRG; n=10) and control group (CON; n=11). TTG and RRG groups trained the dominant knee extensors twice a week with the 10-repetition maximum (RM) load. TTG performed four sets of eight repetitions with three min-rest between sets and RRG 32 repetitions with 17.4 seconds of rest between each one. Before and after interventions, anthropometry, muscle thickness (MT), pennation angle (PA), 1RM, number of repetitions with 10RM pretest load (N10RM), maximum propulsive power (MPP) and maximum voluntary isometric contraction (MVIC) were measured. RESULTS: 1RM of the untrained leg increased only in the TTG group (p<0.001, 10.3% compared with Pre-test). 1RM, MPP and N10RM increased in the trained leg in both TTG (p<0.001) and RRG (p<0.001). No changes occurred in MT or PA. CONCLUSIONS: These results suggest that, when it is not possible to perform bilateral exercises (e.g., leg injury), traditional set configurations should be recommended to improve maximal voluntary force in the untrained leg.