Metabolic Cost of Daily Activities and Effect of Mobility Impairment in Older Adults

Abstract

OBJECTIVES There is a shortage of information on metabolic costs of daily physical activities in older adults and the effect of having mobility impairments. The primary purpose of this study was to evaluate metabolic equivalent (MET) values on common daily tasks in men and women aged > 70 years compared to normative criteria. A secondary purpose was to determine the effect of having mobility impairments. DESIGN Cross-sectional observational study. SETTING University based research clinic PARTICIPANTS Forty-five participants aged 70 to 90 years of age (mean: 76.3 ± 5.1) volunteered to complete 17 daily activities, each lasting 10 minutes. MEASUREMENTS Oxygen consumption (VO2 = ml•kg−1•min−1) was measured through a mask by a portable gas analyzer and MET values were calculated as measured VO2/3.5 ml•kg−1•min−1. Values were compared to both normative values and between participants with and without mobility impairments. RESULTS Compared to the established normative criteria, measured METs were different in 14 of 17 tasks performed. Compared to measured METs, normative values underestimated walking leisurely (0.87 ± 0.12 METs) walking briskly (0.87 ± 0.12 METs ), and bed making (1.07 ± 0.10 METs ), but overestimated gardening (1.46 ± 0.12 METs) and climbing stairs (0.73 ± 0.18). Participants with impairments had significantly lower METs while gardening, vacuuming/sweeping, stair climbing, and walking briskly. However, when METs were adjusted for performance speed the metabolic costs were 16–27% higher for those with mobility impairments. CONCLUSION Compared to normative values, metabolic costs of daily activities are substantially different in older adults and having mobility impairments increases this metabolic cost. These results may have implications for practitioners to appropriately prescribe daily physical activities for healthy and mobility impaired older adults.

The effect of aging on gait parameters in able-bodied older subjects: a literature review

“…Possible explanations for changes in walking speed and stride parameters with aging in researches included: increase of energy cost of walking [36,[51][52][53]58], compensation for muscle weakness [54], and balance impairments [59]. The decreased stride length in the elderly people coincides with weakness in hip extensors and ankle plantar flexors, reduced push-off phase, increased swing phase, and a reduced ability to propel the body forward during gait [60].…”

“…Deterioration in ankle function during customary walking initiates already at middle-age Knaggs et al [51] Crosssectional study N = 45 E Metabolic energy cost Participants with impairments had significantly lower METs while gardening, vacuuming or sweeping, stair climbing, and walking briskly, although when METs were adjusted for performance speed, the metabolic costs were 16-27 % higher for those with mobility impairments Peterson et al [36] Research study…”

“…All of these studies that measure cost of walking or metabolic energy expenditure during walking showed increase of energy consumption with advancing age [23,31,36,42,[51][52][53][54][55]. In comparison studies, Ortega et al and Dean et al reported that the elderly subjects consumed an average of 20 and 26 % more metabolic energy than younger subjects [31,52], whereas they performed an average of 10 % less individual limb work during walking over the range of speeds [52].…”

Activity-Related Energy Expenditure in Older Adults

“…Paragraph Number 4 Few studies have assessed activity-related energy expenditure (e.g., VO 2 ) in older adults (6,9,12,14,17,19). Although scarce, comparative studies show that the energetic cost (i.e., ml/kg/min) of walking and daily activities is higher in older adults compared to younger adults when both are examined at the same time under similar conditions (7,8,14-16).…”

Objective and subjective methods for measuring physical activity and sedentary behaviour in older adults

“…The sample size was larger than samples in similar studies 76,86,88 , however some activities were selected by only a few participants, jeopardising the accuracy of some mean MET estimates. The activities were performed in the participants' own homes, using their own equipment, and no instructions were given on how to perform the activities, in order to capture the full range of habitual performance.…”