Effects of Cognitive Engagement on Physical Performance and Perceived Workload During Isometric Exertions of Index...

ObjectiveThe influence of varying cognitive loading was examined at a moderate level of 25% maximum voluntary contractions (MVC) in a static task.BackgroundRepetitive low-intensity tasks can lead to fatigue, eventually reducing task performance. This study explores the benefits of providing additional cognitive loading during breaks and while performing intermittent tasks on fatigue progression.MethodsIntermittent isometric abductions of the index finger were performed by six male and female subjects for four experimental conditions including passive rest and added cognitive load in the form of an arithmetic task. Both subjective and objective measures of discomfort, muscle activity, physical and mental task performance, muscle capacity, and task demands were compared across genders and conditions.ResultActive breaks with cognitive engagement reduced fatigue compared to passive rest in terms of muscle activity, capacity, and physical demand. Moreover, moderate cognitive demand in concurrence with physical task showed most favorable results as subjects showed lowest perceived fatigue (1.66/10), physical demand (30/100), and muscle activity (0.184 volts) as well as highest muscle capacity retention (92.4%). Further addition of concurrent cognitive demand at a high level showed similar perceived fatigue (1.67/10) and physical demand (32/100) but demonstrated higher muscle activity (0.239 volts) and lower muscle capacity retention (89.9%).ApplicationsFindings demonstrate importance of tailoring cognitive demands based on gender and occupational settings, with moderate mental tasks during breaks offering the most favorable results overall, enhancing recovery and reducing muscle activity without compromising task performance.