Abstract
The purpose of this study was two-fold: (a) to further examine the efficiency of a novel protocol for differentiating maximal from submaximal effort of the knee extensors; and (b) to test the effect of effort performance order: maximal-submaximal vs. submaximal-maximal on the outcome, namely analyze an aspect of internal validity of the protocol. Thirteen women and 17 men took part in the study. They were randomly assigned to one of two groups. Group 1 performed a set of four intermittent maximal (MAX) concentric-eccentric contractions at 30 and 180°/s which was followed by an identical set but at a submaximal level. In the latter set, subjects were asked to exert a submaximal level of force they could best reproduce (BREP). Group 2 performed the same sets but in a reverse order. Results have indicated: (1) no significant differences between the groups, hence prior exposure to maximal effort did not affect the differentiating capacity of the protocol; (2) no significant differences between absolute variability of the MAX and BREP conditions; (3) the DEC parameter defined as the difference in the eccentric/concentric force ratios at the high and low test velocities was highly effective (P < 0.001) in differentiating the MAX from the BREP conditions.