|
|
Updated Physical Activity Guidelines Released
 American College of Sports
Medicine and American Heart Association have provided
physical
activity recommendations for adults and older adults.
All healthy adults ages 18 to 65 years need
moderate-intensity aerobic physical activity for at least 30 minutes on five
days each week or vigorous-intensity aerobic physical activity for at least 20
minutes on three days each week, according to updated physical activity
guidelines released today (Aug 1,2007) by the American College of Sports
Medicine (ACSM) and the American Heart Association (AHA).
Further, adults will benefit from performing activities that maintain or
increase muscular
strength
and endurance for at least two days each week. It is recommended that 8-10
exercises using the major
muscle
groups be performed on two non-consecutive days. To maximize strength
development, a resistance (weight) should be used for 8-12 repetitions of each
exercise resulting in willful fatigue.
The preventive recommendation specifies how adults, by engaging in regular
physical activity, can promote and maintain
health, and reduce
risk of chronic disease
and premature death.
A companion recommendation similar to the updated ACSM/AHA recommendation for
adults is specifically applied to adults aged 65 and older, and adults aged
50-64 with chronic
conditions or physical functional limitations (e.g.
arthritis) that affect
movement ability or physical fitness.
The core recommendation remains fundamentally unchanged despite more than 10
years passing since it was issued. New science has been evaluated to understand
the biological mechanisms by which physical activity provides health benefits
and the physical activity profile (type,
intensity,
amount) that is associated with enhanced health and quality of life. This
publication reflects a review of that evidence, and considers key issues not
fully clarified in the original recommendation.
The updated recommendation for adults is improved in several ways.
 
Moderate-intensity physical activity has been clarified.
The 1995 document specified "most, preferably all days per week" as the
recommended
frequency while the new recommendation identifies five days per week as the
recommended minimum.
Vigorous-intensity physical activity has been explicitly
incorporated into the
recommendation.
To acknowledge both the preferences of some adults for vigorous-intensity
physical activity and the substantial science base related to participation in
such activity, the recommendation has been clarified to encourage participation
in either moderate- and/or vigorous-intensity physical activity.
Vigorous-intensity physical activity was implicit in the 1995 recommendation. It
is now explicitly an integral part of the physical activity recommendation.
Specified: Moderate- and vigorous-intensity activities are
complementary in producing health benefits, and a variety of activities can be
combined to meet the recommendation.
This combining of activities is based on the amount (intensity x duration) of
activity performed during the week and uses the concept of METs (metabolic
equivalents) to assign an intensity value to a specific activity.
Specified: Aerobic activity is needed in addition to routine
activities of daily life.
The updated recommendation now clearly states that the recommended amount of
aerobic activity
(whether of moderate- or vigorous-intensity) is in addition to routine,
light-intensity activities
of daily living, such as self care, casual walking or grocery shopping, or that
last less than 10 minutes, such as
walking to the
parking lot or taking out the trash. Few activities in contemporary life are
conducted routinely at a moderate intensity and last for at least 10 minutes.
However, moderate- or vigorous-intensity activities performed as a part of daily
life (e.g., brisk walking to work, gardening with shovel, carpentry) performed
in bouts of 10 minutes or more can be counted towards the recommendation. This
concept was implied but not effectively communicated in the original
recommendation.
"More is better."
The new recommendation emphasizes the important fact that physical activity
above the recommended minimum amount provides even greater health benefits. The
point of maximum benefit for most health benefits has not been established but
likely varies with genetic endowment, age, sex, health status, body composition
and other factors. Exceeding the minimum recommendation further reduces the risk
of inactivity-related chronic disease. Although the dose-response relation was
acknowledged in the 1995 recommendation, this fact is now explicit.
Short bouts of exercise are OK.
The original recommendation introduced the concept of accumulating short bouts
of physical activity toward the 30-minute goal, but there was confusion about
how short these episodes could be. For consistency, the minimum length of these
short bouts is clarified as being 10 minutes.
A muscle-strengthening recommendation is now included.
Muscle-strengthening activities have now been incorporated into the physical
activity recommendation. The 1995 recommendation mentioned the
importance of muscular
strength and endurance but stopped short of making specific declarations in
this area. Available evidence now allows the integration of muscle strengthening
activities into the core recommendation.
Wording has been clarified.
Minor wording changes in the recommendation have been made to enhance
clarity in communications. For example, the term "aerobic," or endurance, has
been added to clarify the type of physical activity being recommended and to
differentiate it from muscle-strengthening
exercises,
which are now part of the core recommendation.
The updates also provide a clearer sketch of what combinations of moderate- and
vigorous-intensity activity can be performed to meet this recommendation.
Moderate-intensity aerobic activity is described as generally equivalent to a
brisk walk, or activity that noticeably accelerates the
heart rate.
The recommendations also summarize new research that links muscular strength to
health benefits, such as protection against
bone loss and a
decreased risk of all-cause mortality.
The updated recommendations emphasize that relatively modest amounts of physical
activity will improve health; physical activity for cardio-respiratory fitness
and expanded health gains, such as
weight loss, may
require more than a minimum 30 minutes of moderate activity most days of the
week. In general, there are more agreements than differences when it comes to
physical
activity recommendations. Differences on "minutes-per-day" recommendations
appear because they are intended for different groups, and may be
gender-specific or relevant to overweight or
obese individuals.
The papers have published jointly in Medicine & Science in
Sports and Exercise(R), ACSM's official journal and Circulation, a journal of
the American Heart Association. For more information or additional details on
the physical activity guidelines, please visit http://www.americanheart.org/fitness
or http://www.acsm.org/.
SOURCE: American College of Sports Medicine
Related Links
|
|
|
|
|
|
|
