charles matthews

NCI/DCEG

senior investigator

IDATA (Learn more about this study)

IDATA-13

Aug 4, 2017

Influence of exercise or prolonged television viewing days on physical activity and sedentary behaviors in older adults

The emergence of daily sitting time as a risk factor distinct from exercise has prompted physical activity researchers to begin to investigate the health risks and benefits of replacing time spent in one type of behavior for another, and novel behavioral research has begun to leverage time-dependent relationships to increase daily physical activity and improve health. For example, exercising or sitting and watching television for an hour shrinks time available in the waking day for other pursuits, and participation in such behaviors could alter one’s choice of activities in other parts of the day. Although time-use researchers have investigated the trade-offs between sleep and television viewing on use of time for other daily activities, much less is known about how exercise participation or prolonged television viewing on a given day influences time spent in other behaviors and ultimately daily physical activity energy expenditure (PAEE).

For this study, we propose to utilize the Activities Completed Over Time in 24 Hours (ACT24) previous-day recall data, which consists of up to 6 recalls collected over 12-months (one recall every other month) and participant demographic information.

First, we will describe participant characteristics and the amount of time reported (overall) in each of the main time-use categories, as well as the proportion of participants reporting at least one day of exercise (any), prolonged television viewing ( 2 hrs/d), or a work day ( 4 hrs/d). The broad time-use categories will include the following: personal care, household chores, transportation, communication, leisure-time, shopping, caring for others, occupation/work, exercise/sports, lawn and garden, home/auto repair, church/spiritual pursuits, and miscellaneous activities. Next we will describe the sedentary and physical active time and energy expenditure by activity intensity and time-use categories.

To investigate how exercise, prolonged television, and workdays affect physical activity and sedentary time (overall and within time-use categories) we will use mixed linear models with random effects for type of day (i.e., 0,1) as an independent variable to estimate the association between day type and the outcomes of interest (e.g., dependent variables, sleep, waking, active, sedentary time), adjusting for age, sex, season of the year, and day of the week.