Raymond Hernandez, MS, OTR/L; Division of Occupational Science and Occupational Therapy, School of Dentistry, University of Southern California, Los Angeles, California, USA; Jeffrey S. Gonzalez, PhD; Albert Einstein College of Medicine, Bronx, NY; Elizabeth Pyatak, PhD, OTR/L; Division of Occupational Science and Occupational Therapy, School of Dentistry, University of Southern California, Los Angeles, California, USA

Purpose/Objectives
To examine if daily rest and/or leisure frequency moderate the within-person relationship between strenuous (high demand) activities and perceived workload.

Background
We aim to advance understanding of factors affecting whole day workload. Workload is often studied because of its wide applicability and relationship to health and well-being (Bowling et al., 2015). Excessive engagement in strenuous, or high demand activities (Hernandez et al., 2020), and the associated workload are theoretically associated with negative health outcomes (Rau et al., 2010; Sterling & Eyer, 1988). Typically, only workload from work is investigated (Bakker & Demerouti, 2007; Meijman & Mulder, 1998). However, non-work strenuous activities such as caregiving can also be significant sources of workload.

We hypothesized that engagement in more strenuous activities in a day would give rise to greater whole day workload ratings, and that the frequency of rest and leisure activities would moderate their relationship. Both rest and leisure are often cited forms of recovery from work (Sonnentag & Fritz, 2007), so we expected both to moderate the relationship between strenuous activity and workload such that more rest/leisure would weaken the relationship between strenuous activities and workload ratings.

Methods
We analyzed data from 45 workers aged 18 to 75 with type one diabetes (T1D). Nearly 45% of all Americans suffer from at least one chronic condition (Raghupathi & Raghupathi, 2018) and approximately 11% of the US population has diabetes (Centers for Disease Control and Prevention, 2020), so we expect study results to be applicable to a large portion of the general adult population. In brief, participants completed a baseline survey battery, 14 days of ecological momentary assessment (EMA) data collection with 5-6 surveys per day, and a follow-up survey battery.

Survey questions were derived from prior EMA studies or validated global measures. Our whole day workload items were based on the National Aeronautics and Space Administration Task Load Index (NASA-TLX) (Hart & Staveland, 1988). The frequencies of strenuous, restful, and leisure activities relative to the total number of EMA surveys taken in the day were derived from an item asking participants what activity they were doing immediately before each momentary (EMA) prompt.

Mixed-effects modeling was done using the “lme4” package in R (Bates et al., 2007) to account for the nested nature of the data (multiple days nested in an individual). Strenuous activity frequency was the focal predictor, specifically its within-person component. Whole day workload was the dependent variable, and only the intercept was specified as a random effect. Rest and leisure frequency were tested separately as potential moderators.

Findings
Neither rest nor leisure were found to be significant moderators of the relationship between strenuous activity frequency and whole day workload across work and non-work days (p=.099 and p=.0635 for interaction terms, respectively), so we explored the possibility that rest and leisure may only act as moderators on workdays, as prior literature had discussed them as sources of recovery from work (Sonnentag & Fritz, 2007). Three- way interaction terms (within-person strenuous activity frequency, rest/leisure frequency, and workday vs non-workday) were tested for rest and leisure. Only rest was found to have a significant interaction term (beta=-77.58, p=.0187), indicating a different moderation effect for workdays versus non-workdays. Specifically, on non-work days rest did not act as a moderator (interaction term beta=33.66, p=.2978). On workdays however, higher rest frequency decreased the magnitude of workload associated with increases in strenuous activity frequency (interaction term beta=-42.72, p=.0159). This finding is illustrated using “pick-a-point” graphing (Montoya, 2019) as shown in Figure 1, with the dotted line representing the relationship between strenuous frequency and workload when rest frequency is one standard deviation below average, and the solid line depicting the relationship when rest is one standard deviation above average.

Discussion
Both rest and leisure have been described in prior literature as sources of recovery from work (Sonnentag & Fritz, 2007), so leisure’s non-significance as a moderator on workdays may initially seem unexpected. Many leisure activities however, such as playing video games, may have high associated demands (Hernandez et al., 2020) and thus may not promote recovery. Study results suggest that to reduce workload, some workers may benefit by substituting part of their leisure time with rest.

Additional evidence may be needed to demonstrate that our results apply to a general population of working adults. Individuals in our sample all have type 1 diabetes and were experiencing the COVID pandemic during data collection.

Conclusions
Rest, but not leisure, was found to be a significant moderator of the relationship between strenuous frequency and workload for workdays only. Higher rest on workdays decreased the impact of strenuous activity frequency on the magnitude of perceived workload. Workers experiencing excessive workload may benefit from being advised to substitute part of any leisure time they may have with rest.

Tags: Applicable to all occupations/industries, Applied research, Basic research, Sleep and Fatigue, Theoretical and Conceptual Issues in Job Stress, Workplace Stress; Outcomes; and Recovery