Definition of terms. Throughout the review, the
Institute of Medicine’s definitions of physical activity and
exercise and related concepts are adopted, where physical
activity refers to body movement that is produced by the
contraction of skeletal muscles and that increases energy
expenditure. Exercise refers to planned, structured, and
repetitive movement to improve or maintain one or more
components of physical fitness. Throughout the Position
Stand, evidence about the impact of exercise training is
considered for several dimensions of exercise: aerobic
exercise training (AET) refers to exercises in which the
body’s large muscles move in a rhythmic manner for
sustained periods; resistance exercise training (RET) is
exercise that causes muscles to work or hold against an
applied force or weight; flexibility exercise refers to activities
designed to preserve or extend range of motion
(ROM) around a joint; and balance training refers to a
combination of activities designed to increase lower body
strength and reduce the likelihood of falling. Participation in
exercise and the accumulation of physical activity have been
shown to result in improvements in Physical fitness, which is
operationally defined as a state of well-being with a low risk
of premature health problems and energy to participate in a
variety of physical activities. Sedentary living is defined as a
way of living or lifestyle that requires minimal physical
activity and that encourages inactivity through limited
choices, disincentives, and/or structural or financial barriers.
There is no consensus in the aging literature regarding when
old age begins and no specific guidelines about the
minimum age of participants in studies that examine the
various aspects of the aging process. The recently published
ACSM/AHA physical activity and public health recommendations
(167) for older adults suggest that, in most cases,
‘‘old age’’ guidelines apply to individuals aged 65 yr or
older, but they can also be relevant for adults aged 50–64 yr
with clinically significant chronic conditions or functional
limitations that affect movement ability, fitness, or physical
activity. Consistent with this logic, in the present review,
most literatures cited are from studies of individuals aged
65 yr and older; however, occasionally, studies of younger
persons are included when appropriate.
Process. In 2005, the writing group was convened by
the American College of Sports Medicine and charged with
updating the existing ACSM Position Stand on exercise
for older adults. The panel members had expertise in public
health, behavioral science, epidemiology, exercise science,
medicine, and gerontology. The panel initially reviewed the
existing ACSM Position Stand and developed an outline for
the revised statement. Panel members next wrote background
papers addressing components of the proposed
Position Stand, using their judgment to develop a strategy
for locating and analyzing relevant evidence. The panelists
relied as appropriate on both original publications and
earlier reviews of evidence, without repeating them.
Because of the breadth and diversity of topics covered in
the Position Stand and the ACSM requirement that Position
Stands be no longer than 30 pages and include no more than
300 citations, the panel was not able to undertake a systematic
review of all of the published evidence of the benefits
of physical activity in the older population. Rather, the