In the field. Physiologic responses to arm crank exercise with and without hand grasping

This study was designed to determine the relative contribution of the static forearm contractile component to physiologic responses elicited during arm crank ergometry (ACE). Nine able-bodied males completed continuous, incremental ACE tests to exhaustion with and without hand grasping. Use of quadriplegic cuffs enabled the subjects to perform ACE without maintaining a voluntary grip on the hand crank. Peak oxygen uptake (V̇O₂), minute ventilation (V̇(E), heart rate (HR), blood lactate (La), and power output (PO) were not significantly different (p > .05) between the two modes of ACE. Rating of perceived exertion (RPE) was slightly, but significantly, lower during ACE without hand grasping than with grasping. In addition, at four submaximal PO levels, V̇O₂, V̇(E), HR, La, and RPE responses were similar during ACE with and without hand grasping. These data demonstrate that a diminished static hand grasping component does not alter either submaximal or peak physiologic or submaximal perceived exertion responses during ACE. Apparently, static forearm contractions employed to sustain a grip on the hand crank do not contribute significantly to either central command or peripheral afferent input to cardiorespiratory control centers or peak upper-body aerobic metabolic demand.