Accelerometery-Determined Physical Activity and Functional Fitness in Older Adults

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Chronological age inevitably leads to functional fitness decline, even in healthy older adults. However, daily physical activity (PA) may help to ameliorate age-associated decline in functional fitness. PURPOSE: To determine the effect of amount and/or intensity of physical activity on the functional fitness of older adults. METHODS: Older adults were recruited by public postings. Eligible subjects (Ss) underwent a functional fitness battery and received a Lifecorder (Suzuken Co, Japan) accelerometer to track steps and PA intensity (0=low intensity to 9=high intensity) for 2 consecutive weeks. Steps/day was examined as a categorical variable defined as sedentary (SED)(<5,000), low active (LA)(5,000–7,499), and somewhat active (SA)(7,500–9,999). PA intensity was examined as a categorical variable defined as low intensity (L-I) corresponding to accelerometer level 0 and moderate intensity (M-I) corresponding to accelerometer levels 4,5,6 (3-6 METS). RESULTS: Thirty seven men (n=14, 70yrs) and women (n=23, 71yrs) completed assessments. Men and women were significantly different on chair stand, back scratch, and M-I and were analyzed separately. FEMALES: Average daily step count was 7213 (±2694). Seventeen percent were classified SED, 39% LA, and 43% SA. Fifty-seven percent were classified L-I and 43% M-I. MANOVA indicate a significant main effect (F=2.36, p<05) for steps but not for intensity. Univariate tests indicate difference between SED and LA and between LA and SA for up and go and 12-min walk. MALES: Average daily step count was 5932 (±1494). Twenty-nine percent were classified SED, 50% LA, and 21% SA. Ninety-three percent were classified L-I and 7% M-I. MANOVA indicate a significant main effect (F=2.55, p<05) for steps but not for intensity. Univariate tests indicate difference between SED and LA for up and go and 12-min walk. There was no difference between LA and SA. CONCLUSIONS: Although 30 minutes or more of M-I PA on most days of the week is recommended, Ss spent only 15 min (male 8-min, female 19-min) each day performing M-I PA. For both groups, level of intensity did not affect functional fitness. However, only 1 male participated on M-I activity, while 43% of the women participated in M-I activity. The amount of PA did affect two measures of functional fitness, the up and go and the 12-min walk.