The relationship of objectively measured sedentary time (ST), frequency of breaks in ST, and lower extremity function (LEF) was investigated in a diverse sample aged ≥ 70 years (n = 217). Physical activity (PA) was assessed by accelerometry deriving moderate-vigorous PA (MVPA) minutes per registered hour (MVPA min · hr−1), registered ST (ST min · hr−1), and breaks in ST min · hr−1 (breaks · hr−1). LEF was assessed by the Short Physical Performance Battery. Univariate associations with overall LEF were MVPA (r = .523), ST (r = −.499), and breaks (r = .389). Adjusted linear regression including MVPA min · hr−1, ST min · hr−1, and breaks · hr−1 explained 41.5% of LEF variance. Each additional break · hr−1 was associated with 0.58 point increase in LEF. Breaks and MVPA had strongest independent associations with LEF. Promoting regular breaks might be useful in maintaining or increasing LEF and later life independence. This novel finding is important for the design of effective lifestyle interventions targeting older adults.
Mark G. Davis, Kenneth R. Fox, Afroditi Stathi, Tanya Trayers, Janice L. Thompson and Ashley R. Cooper
Tanya Trayers, Debbie A. Lawlor, Kenneth R. Fox, Jo Coulson, Mark Davis, Afroditi Stathi and Tim Peters
Associations of objectively measured physical activity (PA) with objectively measured lower limb function in adults age 70 and older were studied. Lower limb function was assessed using the Short Physical Performance Battery (SPPB) and PA by an accelerometer providing mean daily counts per minute (CPM), mean daily steps and minutes of moderate or vigorous PA (MVPA) per day. A minority (32 [13%]) scored low (≤6 out of a maximum of 12) on the SPPB, but only 3 (1%) achieved recommended PA levels. Adjusting for confounders, the odds ratio of low SPPB (≤6) comparing those in the lowest one third to highest two thirds of mean CPM was 55 (95%CI: 6, 520); for mean steps per day it was 23 (95%CI: 4, 137) and for minutes of MVPA per day 56 (95%CI: 6, 530). Low levels of PA are common and are associated with poor levels of lower limb function in older adults.