Correct, fake and absent pre-information does not affect the occurrence and magnitude of the bilateral force deficit.

The present study examined whether different pre-information conditions could lead to a volitional modulation of the occurrence and magnitude of the bilateral force deficit (BFD) during isometric leg press. Twenty trained male adults (age: 24.5 ± 1.7 years; weight: 77.5 ± 7.1 kg; height: 1.81 ± 0.05 m) were examined on three days within a week. Isometric leg press was performed on a negatively inclined leg press slide. Each participant completed three maximal isometric strength test sessions with different pre-information conditions given in a graphical chart: no pre-information (NPI; first day), false pre-information (FPI; bilateral force > sum of unilateral forces; second or third day) and correct pre-information (CPI; bilateral force < sum of unilateral forces; second or third day) during bilateral, unilateral-left and unilateral-right leg-press. The sum of left- and right-sided force values were calculated for bilateral (FBL = FBL_left + FBL_right) and unilateral (FUL = FUL_left + FUL_right) analyses. Force data for NPI revealed: Mean (SD): FUL_NPI = 3023 N (435) vs. FBL_NPI = 2812 (453); FPI showed FUL_FPI = 3013 N (459) vs. FBL_FPI = 2843 (446) and the CPI revealed FUL_CPI = 3035 (425) vs. FBL_CPI = 2844 (385). The three (no, false, correct) x 2 (FUL, FBL) rANOVA revealed a high significant main effect of Force (F = 61.82, p < 0.001). No significant main effect of the factor Condition and no significant interaction between Force x Condition was observed. The BFD does not rely on the trueness of the given pre-information (no, false, correct). Cognition-based volitional influences on the BFD on supra-spinal level seem negligible. Key pointsBFD is reliable occurring phenomenonAvailable theoretical knowledge does not affect the BFDAlternating sport should include alternating strength exercises.