94. ACUTE FATIGUE LEVELS ARE IMPROVED BY BRIEF STANDING BREAKS IN PROLONGED SITTING AMONG OLDER POSTMENOPAUSAL WOMEN.

Introduction

Fatigue is a prevalent symptom experienced in older adults. Prolonged sitting is associated with increased fatigue and adverse mental health. Emerging evidence shows that breaking up sitting time with light activity breaks or stands may reduce fatigue in sedentary workers and individuals with type 2 diabetes. However, little is known regarding the effect of breaking up sitting time on the acute fatigue levels in postmenopausal women. This study aimed to investigate the effect of interrupting sitting time with different standing interventions on the acute fatigue levels in older postmenopausal women.

Methods

This two-site, three-condition randomized controlled crossover trial, the Rise for Health - Lab study, enrolled postmenopausal women with overweight or obesity (n=79; mean ± SD age 67 ± 7 years and BMI 32.52 ± 5.15 kg/m2). Participants completed three 5-hr conditions in a clinical laboratory setting: frequent sit- to- stands (STS – 2-minute stand every 15 minutes), hourly standing breaks (HSB – 8-minute stand every hour), and prolonged sitting (control) in a randomized order, separated by a minimum 7-day washout period before crossover. The secondary outcome of fatigue was assessed hourly using the 18-item Lee Fatigue Scale, which yields a total fatigue score as well as fatigue and energy subscale scores. The net incremental area under the curve (iAUC) was investigated via linear mixed models to evaluate each interruption modality versus the control condition. The significance level was set as 0.025 to account for multiple comparisons (e.g., 2 intervention conditions vs. control).

Results

Seventy-six participants completed at least one study visit and were included in the analysis. After adjusting for site, STS significantly reduced mean iAUC fatigue subscale scores by 81% (-24.8, SE: 10.8, p=0.02) and mean iAUC total fatigue scores by 93% (-25.3, SE: 9.3, p=0.008) compared to the control. STS improved iAUC energy subscale score by 156% (26.4, SE: 10.6, p=0.01) compared to the control. The HSB condition was not associated with significant differences in the iAUC fatigue subscale score (p=0.26), iAUC energy subscale score (p=0.21), or iAUC total fatigue score (p=0.18) compared to the control condition.

Conclusions

Frequently breaking up prolonged sitting with brief standing breaks may reduce acute fatigue in postmenopausal women with overweight or obesity. These findings may provide geriatric practitioners and caregivers with a practical and feasible non-pharmacological option for the treatment of fatigue in older adults.