<b><i>Background/Aims:</i></b> Walking speed (WS) is an objective measure of physical capacity and a modifiable risk factor of morbidity and mortality in the elderly. In this study, we (i) determined effects of 3-month supervised aerobic-strength training on WS, muscle strength, and habitual physical activity; (ii) evaluated capacity of long-term (21 months) training to sustain higher WS; and (iii) identified determinants of WS in the elderly. <b><i>Methods:</i></b> Volunteers (F 48/M 14, 68.4 ± 7.1 years) completed either 3-month aerobic-strength (3 × 1 h/week, <i>n</i> = 48) or stretching (active control, <i>n</i> = 14) intervention (study A). Thirty-one individuals (F 24/M 7) from study A continued in supervised aerobic-strength training (2 × 1 h/week, 21 months) and 6 (F 5/M 1) became nonexercising controls. <b><i>Results:</i></b> Three-month aerobic-strength training increased preferred and maximal WS (10-m walk test, <i>p</i> < 0.01), muscle strength (<i>p</i> < 0.01) and torque (<i>p</i> < 0.01) at knee extension, and 24-h habitual physical activity (<i>p</i> < 0.001), while stretching increased only preferred WS (<i>p</i> < 0.03). Effect of training on maximal WS was most prominent in individuals with baseline WS between 1.85 and 2.30 m·s<sup>−1</sup>. Maximal WS measured before intervention correlated negatively with age (<i>r</i> = −0.339, <i>p</i> = 0.007), but this correlation was weakened by the intervention (<i>r</i> = −0.238, <i>p</i> = 0.06). WS progressively increased within the first 9 months of aerobic-strength training (<i>p</i> < 0.001) and remained elevated during 21-month intervention (<i>p</i> < 0.01). Cerebellar gray matter volume (MRI) was positively associated with maximal (<i>r</i> = 0.54; <i>p</i> < 0.0001) but not preferred WS and explained >26% of its variability, while age had only minor effect. <b><i>Conclusions:</i></b> Supervised aerobic-strength training increased WS, strength, and dynamics of voluntary knee extension as well as habitual physical activity in older individuals. Favorable changes in WS were sustainable over the 21-month period by a lower dose of aerobic-strength training. Training effects on WS were not limited by age, and cerebellar cortex volume was the key determinant of WS.
The association between knee joint muscle activation and knee joint moment patterns during walking in moderate medial compartment knee osteoarthritis: implications for intervention
