Nonexercise movement in elderly compared with young people

Abstract

-The association between freeliving daily activity and aging is unclear because nonexercise movement and its energetic equivalent, nonexercise activity thermogenesis, have not been exhaustively studied in the elderly. We wanted to address the hypothesis that free-living nonexercise movement is lower in older individuals compared with younger controls matched for lean body mass. Ten lean, healthy, sedentary elderly and 10 young subjects matched for lean body mass underwent measurements of nonexercise movement and body posture over 10 days using sensitive, validated technology. In addition, energy expenditure was assessed using doubly labeled water and indirect calorimetry. Total nonexercise movement (acceleration arbitrary units), standing time, and standing acceleration were significantly lower in the elderly subjects; this was specifically because the elderly walked less distance per day despite having a similar number of walking bouts per day compared with the young individuals. The energetic cost of basal metabolic rate, thermic effect of food, total daily energy expenditure, and nonexercise activity thermogenesis were not different between the elderly and young groups. Thus, the energetic cost of walking in the elderly may be greater than in the young. Lean, healthy elderly individuals may have a biological drive to be less active than the young.nonexercise activity thermogenesis; physical activity monitoring system; sarcopenia THE AGING POPULATION is increasing in size. For example, in the US, by census data in 2005 there were ϳ37 million people aged Ն65 yr. By 2020, it is predicted, there will be ϳ54 million, and by 2050 ϳ87 million people in the US will be age 65 yr and over (10). Worldwide in 2000, there were 606 million people aged 60 yr and above, and it is predicted that by 2050 this will increase to two billion (9). Overall, the population and number of elderly people is increasing worldwide.Free-living nonexercise movement declines with aging in several animal species, including worms, fruit-flies, rats, mice, cats, and dogs (17, 23, 25-27, 37, 39). The decline in nonexercise movement with aging could be important in human science. This is because low levels of overall nonexercise movement may be associated with the loss of muscle associated with aging, termed sarcopenia. The sarcopenia of aging, in turn, is associated with physical disability in the elderly, resulting in increased morbidity (1,15,16,24). Thus, freeliving nonexercise movement is important both for understanding the biology of aging and for its health implications (22).Nonexercise movement has been widely assumed to decrease in humans with aging; however, this has not been objectively assessed. The reason that so little is known about nonexercise movement in the elderly is the difficulty of measuring this variable in free-living people. However, validated tools have recently become available to do this (18 -20), and so we are able to detail free-living nonexercise movement and its components in healthy elderly people.Nonexercise move...

Effects of posture on shear rates in human brachial and superficial femoral arteries

“…It is important to describe brachial and superficial femoral artery SRs in the seated and upright postures because the average American spends two-thirds of his or her day in these postures (10,17). We hypothesized that increases in MSNA associated with upright posture would decrease superficial femoral artery diameter to a greater extent than brachial diameter.…”

“…Based on these observations, these authors noted that wall SRs in the vasculatures of the upper and lower extremities reflected the differences in propensity for atherosclerosis (17,37). Since this proposal of Wu et al (37) is based on brachial and superficial femoral artery SRs measured only in the supine position, this conclusion should be considered cautiously, because the average American spends only one-third of the day in the supine position (10,17). The remaining two-thirds of the day are spent in either the seated or standing postures.…”

“…Resting conditions contribute to the majority of this time spent in the upright posture since the average American spends only 1 h a day walking or running (38). Therefore, measurements of limb vasculature SRs in these postures during rest are critical for a complete understanding of the potential role of shear stress on the heterogeneous distribution of atherosclerosis in the limb vasculatures (10,17).…”

The Role of Free-Living Daily Walking in Human Weight Gain and Obesity

“…We have reported previously that factorial determinations of NEAT from PAMS showed a linear positive relationship with total NEAT calculated from doubly labeled water (corrected ICC ϭ 0.90, P Ͻ 0.001) (7) and with room calorimeter measurements (12,13). This approach was validated using a room calorimeter (12) and doubly labeled water (7,14). Data analysis and statistics.…”

Energy Expenditure Responses To Exercise Training In Older Women

“…Using a NEAT value of 3024 AE 1214 kJÁday À1 reported for older adults (Harris et al 2007), 36 women per group completing the study would provide at least 85% power with an a of 0.05 to detect the estimated difference between groups. Variables were reported as means (AESDs) for normally distributed variables, medians (quartiles) for non-normally distributed variables, or frequencies in percentages.…”