Background: Breaking up sedentary behavior with standing or walking can decrease discomfort, fatigue, and sleepiness. However, less is known about acceptability and impact of resistance exercise breaks on these outcomes. Therefore, we evaluated the acceptability of resistance exercise breaks and their influence on discomfort, physical and mental fatigue, and sleepiness during occupational sitting.
Methods: Workers completed two 4-hour conditions in random order: prolonged sitting (SIT) and sitting with hourly resistance exercise breaks (REX). All outcomes were measured at baseline and every hour thereafter with five total breaks. Linear mixed models evaluated overall condition effects and differences at each hour. Cohen's d estimated magnitudes of effect. Acceptability was assessed via questionnaire after the REX condition and reported as percentages.
Findings: Fourteen adults (age: 53.4 ± 9.5 years, body mass index [BMI]: 30.9 ± 4.8 kg/m2) were enrolled. Although ratings of discomfort, fatigue, and sleepiness were typically lower during REX as compared with SIT, overall outcomes were not significantly different between conditions (p > .05). However, a significant reduction in mental fatigue at hour 4 in favor of the REX condition (β = -0.48 log-points, p < .05, d = 0.37) was observed. Program acceptability questions revealed the majority (>50%) of participants reported a "4" or "5" on a 5-point Likert-type scale for all questions, indicating high acceptability for implementation.
Conclusions/application to practice: Resistance exercise breaks had high acceptability and provided preliminary evidence of improving ratings of mental fatigue. More research is needed to better understand the role of resistance training to reduce sedentary behavior.
Keywords: discomfort; fatigue; prolonged sitting; sedentary behavior; sleepiness.