The purpose of the study was to evaluate the accuracy of direct observation (DO) to estimate MET level and intensity category during laboratory-based and free-living activity in older adults. Older adults engaged in unstructured laboratory and free-living activity. Participants wore a portable metabolic system to measure energy expenditure and were directly observed. DO recorded MET-level point estimates. 32,401 in-laboratory and 87,715 free-living data points (9 participants, 67% male, 71.0 ± 6.9 years, 27.1 ± 4.3 kg·m–2) were included in final analysis. Results revealed 45.4% of in-laboratory and 61.1% of free-living mean DO activities fell within 0.5 METs of the measured MET values. DO accurately classified intensity category 45.0% of the time in-laboratory and 50.9% of free-living observations. DO-estimated activity cost resulted in low point estimate accuracy however there was low variability between the mean measured and estimated METs. This suggests, dependent on the desired outcome, DO could provide a viable option for activity assessment, however, the low point estimate accuracy presents a need for further research to continue to refine the approach to increase accuracy.
Whitney A. Welch, Ann M. Swartz, Chi C. Cho and Scott J. Strath
Jeremy A. Steeves, David R. Bassett, Eugene C. Fitzhugh, Hollie Raynor, Chi Cho and Dixie L. Thompson
Physical activity (PA) is enjoyable, but there are barriers to participation. TV viewing is highly enjoyable with limited barriers. Exercising while viewing TV may impact enjoyment, exercise self-efficacy, and barriers to PA, compared with exercising without TV.
58 sedentary, overweight adults were randomized to 1 of 2 PA prescriptions: one that increased PA during TV viewing (TV Commercial Stepping), and another that focused solely on PA (Walking). Random effects models tested changes in enjoyment of TV and PA, exercise self-efficacy, and barriers to PA across time (baseline, 3, and 6 months) and PA prescription during a 6-month PA intervention.
At baseline, TV was more enjoyable than PA. Over the 6-month intervention, enjoyment of TV viewing did not change, but enjoyment of PA and exercise self-efficacy significantly increased, while barriers to PA significantly decreased for both groups compared with baseline (P < .05).
While enjoyment of TV viewing remained constant, PA became more enjoyable, confidence to exercise increased, and barriers to being active were reduced for previously sedentary adults participating in a behavioral PA intervention. These findings highlight the importance of encouraging inactive adults to engage in some form of PA, whether it occurs with or without TV viewing.