TY - JOUR
T1 - Association between energy availability and physical activity in older adults
AU - Schrager, Matthew A.
AU - Schrack, Jennifer A.
AU - Simonsick, Eleanor M.
AU - Ferrucci, Luigi
N1 - Publisher Copyright:
Copyright © 2014 by Lippincott Williams & Wilkins.
PY - 2014
Y1 - 2014
N2 - Objective: Age-related declines in physical activity are commonly observed in human and animal populations, but their physiologic bases are not fully understood. The authors hypothesize that a lack of available energy contributes to low levels of activity in older persons.Design: Cross-sectional analyses of relationships between physical activity level and energy availability were performed in 602 community-dwelling volunteers aged 45Y91 yrs from the Baltimore Longitudinal Study of Aging. Energy expenditure was measured at rest and during a maximal 400-m walk for calculation of "available energy." Overall and vigorous physical activity levels were assessed using standardized questionnaires. General linear regression models were used to assess the relationships between available energy and general and vigorous physical activity, and stratified analyses were used to analyze the possible differential association between available energy and physical activity across high and low (peak sustained walking oxygen consumption per unit time, <18.3 ml of oxygen per kilogram per minute) levels of aerobic fitness.Results: Low available energy was associated with low levels of total physical activity (β = 64.678, P = 0.015) and vigorous activity (β = 9.123, P < 0.0001). The direct relationship between available energy and physical activity was particularly strong in persons categorized as having low aerobic fitness between available energy and physical activity with both total (β = 119.783, P = 0.022) and vigorous activity (β = 10.246, P = 0.015) and was independent of body composition and age.Conclusions: The findings from this study support the hypothesis that available energy promotes the maintenance of physical activity in older persons. The findings also run counter to the perception that age-related declines in physical activity are primarily societally or behaviorally driven.
AB - Objective: Age-related declines in physical activity are commonly observed in human and animal populations, but their physiologic bases are not fully understood. The authors hypothesize that a lack of available energy contributes to low levels of activity in older persons.Design: Cross-sectional analyses of relationships between physical activity level and energy availability were performed in 602 community-dwelling volunteers aged 45Y91 yrs from the Baltimore Longitudinal Study of Aging. Energy expenditure was measured at rest and during a maximal 400-m walk for calculation of "available energy." Overall and vigorous physical activity levels were assessed using standardized questionnaires. General linear regression models were used to assess the relationships between available energy and general and vigorous physical activity, and stratified analyses were used to analyze the possible differential association between available energy and physical activity across high and low (peak sustained walking oxygen consumption per unit time, <18.3 ml of oxygen per kilogram per minute) levels of aerobic fitness.Results: Low available energy was associated with low levels of total physical activity (β = 64.678, P = 0.015) and vigorous activity (β = 9.123, P < 0.0001). The direct relationship between available energy and physical activity was particularly strong in persons categorized as having low aerobic fitness between available energy and physical activity with both total (β = 119.783, P = 0.022) and vigorous activity (β = 10.246, P = 0.015) and was independent of body composition and age.Conclusions: The findings from this study support the hypothesis that available energy promotes the maintenance of physical activity in older persons. The findings also run counter to the perception that age-related declines in physical activity are primarily societally or behaviorally driven.
KW - Aerobic Fitness
KW - Aging
KW - Energy
KW - Physical Activity
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U2 - 10.1097/PHM.0000000000000108
DO - 10.1097/PHM.0000000000000108
M3 - Article
C2 - 24800719
AN - SCOPUS:84909646512
SN - 0894-9115
VL - 93
SP - 876
EP - 883
JO - American Journal of Physical Medicine and Rehabilitation
JF - American Journal of Physical Medicine and Rehabilitation
IS - 10
ER -