Da. Skelton et al., EFFECTS OF RESISTANCE TRAINING ON STRENGTH, POWER, AND SELECTED FUNCTIONAL ABILITIES OF WOMEN AGED 75 AND OLDER, Journal of the American Geriatrics Society, 43(10), 1995, pp. 1081-1087
OBJECTIVE: To determine the effects of 12 weeks of progressive resista
nce strength training on the isometric strength, explosive power, and
selected functional abilities of healthy women aged 75 and over. DESIG
N: Subjects were matched for age and habitual physical activity and th
en randomly assigned into either a control or an exercise group. SETTI
NG: The Muscle Function Laboratory, Royal Free Hospital School of Medi
cine, London. PARTICIPANTS: Fifty-two healthy women were recruited thr
ough local and national newspapers. Five dropped out before and seven
(4 exercisers and 3 controls) during the study. Pre- and posttraining
measurements were obtained from 20 exercisers (median age 79.5, range
76 to 93 years) and 20 controls (median age 79.5, range 75 to 90 years
). INTERVENTIONS: Training comprised one supervised session (1 hour) a
t the Medical School and two unsupervised home sessions (supported by
an exercise tape and booklet) per week for 12 weeks. The training stim
ulus was three sets of four to eight repetitions of each exercise, usi
ng rice bags (1-1.5 kg) or elastic tubing for resistance. The exercise
s were intended specifically to strengthen the muscles considered rele
vant for the functional tasks, but were not to mimic the functional me
asurements. No intervention was prescribed for the controls. MEASUREME
NTS: Pre- and posttraining measurements were made for isometric knee e
xtensor strength (IKES), isometric elbow flexor strength (IEFS), handg
rip strength (HGS), leg extensor power (LEP), and anthropometric indic
es (Body impedance analysis, arm muscle circumference, and body weight
). Functional ability tests were chair rise, kneel rise, rise from lyi
ng on the floor, 118-m self-paced corridor walk, stair climbing, funct
ional reach, stepping up, stepping down, and lifting weights onto a sh
elf. Pre- and posttraining comparisons were made using analysis of var
iance or analysis of covariance (using weight as a covariate) for norm
ally distributed continuous data and one-sided Fishers exact test (2x2
table) for discontinuous data. RESULTS: Improvements in IKES (mean ch
ange 27%, P = .03), IEFS (22%, P = .05), HGS (4%, P = .05), LEP/kg (18
%, P = .05) were associated with training, but the improvement in LEP
(18%, P = .11) did not reach statistical significance. There was an as
sociation between training and a reduction in normal pace kneel rise t
ime (median change 21%, P = .02) and a small improvement in step up he
ight (median 5%, P = .005). The other functional tests did not improve
. CONCLUSIONS: Progressive resistance exercise can produce substantial
increases in muscle strength and in power standardized for body weigh
t in healthy, very old women. However, isolated increases in strength
and LEP/kg may confer only limited functional benefit in healthy, inde
pendent, very old women.