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Physical activity moderates the effect of sedentary time on an older adult's physical independence
Author(s) -
HetheringtonRauth Megan,
Magalhães João P.,
Júdice Pedro B.,
Ara Ignacio,
Rosa Gil B.,
Correia Inês R.,
Mañas Asier,
Sardinha Luís B.
Publication year - 2021
Publication title -
journal of the american geriatrics society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.992
H-Index - 232
eISSN - 1532-5415
pISSN - 0002-8614
DOI - 10.1111/jgs.17141
Subject(s) - medicine , moderation , physical activity , physical therapy , sedentary behavior , sedentary lifestyle , gerontology , demography , independence (probability theory) , psychology , social psychology , sociology , statistics , mathematics
Background/objectives Moderate‐to‐vigorous physical activity (MVPA) and breaks in sedentary time (BST) have been proposed as viable solutions to improve an older adult's physical independence, whereas sedentary time (ST) has been associated with detrimental effects. We sought to assess the joint effects of ST, BST, and MVPA on the physical independence of older adults and determine whether and to what extent the ST relationship with physical independence is moderated by MVPA and/or BST. Design Cross‐sectional. Setting Laboratory of Exercise and Health, Faculty of Human Kinetics. Participants Older adults (≥65 years old) from the national surveillance system in Portugal ( n = 821). Measurements Physical activity and ST were assessed by accelerometry. Physical independence was assessed using a 12‐item composite physical function (CPF) questionnaire. Multiple linear regression was used to model the outcomes. Results Higher ST was related to lower CPF score ( β = −0.01, p < 0.0001), whereas higher MVPA was related to better CPF score ( β = 0.02, p < 0.0001). BST was not related to physical independence after accounting for MVPA and ST ( β = 0.03, p = 0.074). MVPA had a moderating effect on the relationship of ST with CPF score ( p < 0.0001), where MVPA ≥36.30 min/day ameliorated the significant inverse relationship between ST and CPF. Engaging in ≥107.78 of MVPA resulted in ST having a significant positive relationship with CPF score. No moderation effect was found for BST ( p > 0.05). Conclusion Regardless of the time spent in MVPA and BST, ST was inversely related to CPF. However, MVPA was found to be a moderator of the relationship between ST and physical independence, such that engaging in at least 36 min/day of MVPA may blunt the negative effects of ST. At high levels of MVPA (≥108 min/day), having some ST may actually provide some benefit to an older adult's ability to maintain physical independence.