Interaction of physical and mental work

Effects of Combining Occupationally Relevant Physical and Cognitive Tasks. A Systematic Review

OBJECTIVES

Physical and cognitive tasks occur together in many occupations. Previous reviews of combined tasks have mainly focused on their effects in a sports context. This review investigated to which extent combinations (concurrent or alternating) of occupationally relevant physical and cognitive tasks influence responses reflecting biomechanical exposure, stress, fatigue, performance, and well-being.

METHODS

We searched Scopus, Pubmed, Cinahl, and Psychinfo for controlled experiments investigating the effects of combinations of occupationally relevant physical and cognitive tasks in participants aged 18 to 70. In total, we identified 12 447 records. We added recent papers that had cited these studies (n = 573) to arrive at a total of 13 020 publications. After screening for relevance, 61 studies remained, of which 57 were classified to be of medium or high quality. Of the 57 studies, 51 addressed concurrent tasks, 5 alternating tasks, and 1 both concurrent and alternating tasks.

RESULTS

Most studies of concurrent physical and cognitive tasks reported negative effects, if numerically small, on indicators of biomechanical exposure, fatigue, and performance, compared to a physical task alone. Results were mixed for stress indicators, and well-being was too little studied to justify any conclusions. Effects depended on the tasks, including their intensity and complexity. Alternating physical and cognitive tasks did not appear to influence outcomes much, compared to having passive breaks in-between physical tasks.

CONCLUSIONS

The reviewed evidence indicated that concurrent physical and cognitive work tasks have negative, yet small effects on biomechanical indicators, fatigue and performance, compared to performing the physical task alone, but only if the physical task is intense, and the cognitive task is complex. Alternating between physical and cognitive tasks may have similar effects as breaking up physical tasks by passive breaks, but studies were few. Future studies should address ecologically valid combinations of physical and cognitive tasks, in particular in controlled field studies devoted to the long-term effects of combined work.

Effects of mento-physical exercises on mental fatigue of shift work

Objectives. This study aims to investigate whether mento-physical exercises can decrease mental fatigue during shift work. Methods. Research subjects including the control room staff of an urban train system were chosen randomly, for whom mental fatigue was assessed before and after rest breaks for control and experimental groups. A new protocol was applied in the experimental group, including breathing exercises, isometric and isotonic exercises, and progressive relaxation during the inter-shift break. A designed questionnaire and the Stroop test were used to evaluate fatigue and the reaction time, respectively. Results. Pre and post-test results showed that mental, visual and physical fatigue and reaction time decreased by 14.48, 49.22, 26.85 and 8.35% in the control group and 36.42, 48.48, 76.37 and 20.56% in the experimental group, respectively. Conclusions. At the 5% α level, Student's t test showed that mento-physical exercises effectively decreased mental and physical fatigue as well as reaction time in the experimental group compared to the control group.

Compensation for Adolescents' School Mental Load by Physical Activity on Weekend Days

INTRODUCTION AND OBJECTIVE

Increasing mental load and inadequate stress management significantly affect the efficiency, success and safety of the educational/working process in adolescents. The objective of this study is to determine the extent that adolescents compensate for their school mental load by physical activity (PA) on weekend days and, thus, to contribute to the objective measurement of mental load in natural working conditions.

METHODS

A cross-sectional study was conducted between September 2013 and April 2014. A set of different methods was employed-self-administered questionnaire (IPAQ-long questionnaire), objective measurements-pedometers, and accelerometers (ActiTrainers). They was distributed to 548 students from 17 high schools. Participants' mental load was assessed based on the difference between PA intensity and/or physical inactivity and heart rate range.

RESULTS

The participants with the highest mental load during school lessons do not compensate for this load by PA on weekend days.

CONCLUSIONS

Adolescents need to be encouraged to be aware of their subjective mental load and to intentionally compensate for this load by PA on weekend days. It is necessary to support the process of adopting habits by sufficient physical literacy of students, as well as teachers, and by changes in the school program.