Progressive Resistance Strength Training May Help Improve Physical Function in Older Adults

July 28, 2009 — Progressive resistance strength training (PRT) may
improve physical function in older adults, according to the results of a
systematic review reported online in the July 8 issue of Cochrane
Database of Systematic Reviews.

“Muscle weakness in old age is associated with physical function
decline,” write Dr. Chiung-ju Liu, from Indiana University at
Indianapolis, and Dr. Nancy K. Latham, from the School of Public Health,
Boston University in Boston, Massachusetts. “…PRT exercises are
designed to increase strength.”

The goals of this review were to evaluate the effects of PRT on older
people and to identify adverse events. The reviewers searched the
Cochrane Bone, Joint and Muscle Trauma Group Specialized Register to
March 2007; the Cochrane Central Register of Controlled Trials (The
Cochrane Library 2007, Issue 2); MEDLINE from 1966 to May 1, 2008;
EMBASE from 1980 to February 6, 2007; CINAHL from 1982 to July 1, 2007;
and 2 other electronic databases. In addition, the reviewers searched
bibliographies of identified articles, reviewed abstracts from
conference proceedings, and contacted investigators of the original studies.

Criteria for inclusion of studies in the review were randomized
controlled trials of PRT in older participants that evaluated and
reported on physical outcomes. Both review authors independently
identified trials meeting selection criteria, evaluated the methodologic
quality of the trials, and extracted data to be pooled when appropriate.

The reviewers identified 121 trials that met selection criteria. These
enrolled a total of 6700 participants, and in most trials, PRT was given
at high intensity 2 to 3 times per week. PRT was associated with a
small, significant improvement in physical ability (33 trials, 2172
participants; standardized mean differences [SMD], 0.14; 95% confidence
interval [CI], 0.05 – 0.22).

There were also improvements in measures of functional limitation. For
example, gait speed improved modestly (24 trials, 1179 participants; MD,
0.08 meters per second; 95% CI, 0.04 – 0.12), and ability to get out of
a chair showed moderate to large improvements (11 trials, 384
participants; SMD, -0.94; 95% CI, -1.49 to -0.38). Furthermore, there
was a large positive effect of PRT on muscle strength (73 trials, 3059
participants; SMD, 0.84; 95% CI, 0.67 – 1.00).

Decreased pain after PRT was reported in 6 trials enrolling a total of
503 participants with osteoarthritis (SMD, -0.30; 95% CI, -0.48 to
-0.13). However, 10 other trials enrolling a total of 587 participants
provided no evidence that PRT had any effect on bodily pain.

In most trials, adverse events were poorly recorded. However, many of
the studies that prospectively defined and monitored adverse events
showed that most of these were musculoskeletal complaints including
joint pain and muscle soreness. Serious adverse events were rare
overall, and none were directly attributed to the exercise program.

“This review provides evidence that PRT is an effective intervention for
improving physical functioning in older people, including improving
strength and the performance of some simple and complex activities,” the
review authors write. “However, some caution is needed with transferring
these exercises for use with clinical populations because adverse events
are not adequately reported.”

Limitations of the review include high dropout rates in some of the
included trials, generally poor methodologic quality, heterogeneity in
the data, and low frequency of reporting any monitoring for adverse events.

“Doing PRT two to three times a week can improve physical function in
older adults, including reducing physical disability, some functional
limitations (i.e. balance, gait speed, timed walk, timed ‘up-and-go’,
chair rise; and climbing stairs) and muscle weakness in older people,”
the review authors conclude. “Therefore, it would appear to be an
appropriate intervention for many older people to improve performance of
some simple physical tasks. The training also shows a reduction in pain
in people with osteoarthritis. “

The National Institute of Disability and Rehabilitation Research
provided a postdoctoral fellowship to the first review author through
Boston University and Switzer research. The second review author
received support from the National Institute of Aging and through a
Pepper Center Trainee award from Boston Pepper Center funded by the
National Institute of Aging.

Cochrane Database Syst Rev. Published online July 8, 2009.