Article

Peak energy expenditure is highly correlated with usual gait speed;
however, it is unknown whether the energetic cost of walking is also an important
contributor to usual gait speed when considered as a component of peak walking
capacity. DESIGN: The energetic cost of 5 mins of slow treadmill walking (0.67
m/sec), peak overground walking energy expenditure, and usual gait speed over 6 m
were assessed cross-sectionally in 405 adults aged 33 to 94 yrs in the Baltimore
Longitudinal Study of Aging. RESULTS: Mean (SD) energy expenditures during slow
and peak sustained walking were 8.9 (1.4) and 18.38 (4.8) ml kg(-1) min(-1),
respectively. Overall, the energetic cost of slow walking as a percentage of peak
walking energy expenditure was strongly associated with usual gait speed (P <
0.001); however in stratified analyses, this association was maintained only in
those with peak walking capacity below 18.3 ml kg(-1) min(-1)
(P = 0.04), the
threshold associated with independent living. CONCLUSIONS:
In older persons with
substantially reduced peak walking capacity, the energetic cost of walking is
associated with gait speed, particularly when peak walking capacity nears the
minimum level considered necessary for independent living. Thus, optimal
habilitation in older frail persons may benefit from both improving fitness and
reducing the energetic cost of walking.

Langue : ANGLAIS