Within the choice of exercises, you can choose exercises that are performed unilaterally (performed with a member at a time) or bilateral (exercise performed with the corresponding members simultaneously). Several studies have reported significant differences in maximum loads compared between types of exercise (OWINGS and Grabiner, 1998; VAN DIEEN, Ogita and De HAAN, 2003; KURUGANTI and MURPHY, 2008; Ohtsuki, 1983; ODA and Moritani, 1996; Schantz et al., 1989), where the sum of the maximum loads of both members, the sum of the loads in unilateral contractions exceeds the load carried in bilateral contraction. This is called bilateral deficit.
This phenomenon can occur in both large muscle groups as in small, regardless of sex and physical condition of the individual (Ohtsuki, 1983; HOWARD and Enoka, 1991; KURUGANTI and MURPHY, 2008). The factor that can be considered the most influential in the occurrence of bilateral deficit is the neural limitation in the cerebral cortex during bilateral maximal contractions (OWINGS and GRABNER, 1998; Ohtsuki, 1983). In a twitch when one of the hemispheres is in action, it decreases the activation of the opposite hemisphere, causing less force production (VAN DIEEN, Ogita and De HAAN, 2003). Thus, in unilateral exercises, due to only one hemisphere to be active, can cause recruitment Maximo fiber and therefore maximum strength.