Health Psychology
2000, Vol. 19, No. KSuppl.), 32-41
Copyright 2000 by the American Psychological Association, Inc.
0278-6133/00/S5.00 DOI: 10.1037//0278-6133.19.1(Suppl.).32
Physical Activity Behavior Change: Issues in Adoption andMaintenance
Bess H. Marcus
The Miriam Hospital
Patricia M. Dubbert
Veterans Affairs Medical Center, Jackson, Mississippi
LeighAnn H. Forsyth
The Miriam Hospital
Thomas L. McKenzie
San Diego State University
Elaine J. Stone
National Heart, Lung, and Blood Institute
Andrea L. Dunn and Steven N. Blair
Cooper Institute for Aerobics Research
The many benefits of participation in regular moderate- or vigorous-intensity physical activity
are well established, yet more than 60% of the population is sedentary or insufficiently active.
Published studies have revealed that behavior modification and cognitive-behavior modification can be successfully used to assist patients, healthy adults, and youth in the adoption of
physically active lifestyles. However, few studies with adults and youth have examined the
maintenance of physical activity behavior beyond 6 months of adoption of this behavior.
Maintenance of physical activity is critically important because ongoing participation in the
behavior is necessary to sustain health benefits. Knowledge of effective intervention strategies
for long-term maintenance of physical activity is at an early stage. The authors provide a
summary of what is known about the maintenance of physical activity behavior in adults and
youth and how physical activity behavior relates to other health behaviors such as smoking, as
well as recommendations for research on physical activity behavior change and maintenance.
Key words: physical activity, exercise, behavioral interventions, maintenance
The many benefits of engaging in regular physical activity
are now generally accepted (Bouchard, Shephard, & Stephens, 1994; U.S. Department of Health and Human Services [USDHHS], 1996). Physical activity affects many
aspects of health, including protection against premature
mortality, coronary heart disease, hypertension, diabetes
mellitus Type 2, osteoporosis, colon cancer, depression, and
anxiety (Bouchard et al., 1994; USDHHS, 1996). Despite
these benefits, much of the population is sedentary or
underactive. Although several trials demonstrated success in
encouraging adoption of physical activity in both patient and
healthy populations, few studies examined the maintenance
of this behavior. Maintenance is a noteworthy endeavor
given that individuals must continue to be physically active
to sustain its full health benefits. Knowledge of effective
intervention strategies to change and maintain physical
activity behavior in free-living settings is still at an early
stage. It was not until 1996 that the first U.S. surgeon
general's report documenting the benefits of physical activity was published. This is a document comparable to the first
publications of the surgeon general's recommendations
for smoking and nutrition published in 1964 and 1988,
respectively. The purpose of this article is to summarize
what is known about the maintenance of physical activity
behavior in adults and youth and to recommend directions
for research on physical activity behavior change and
maintenance.
Bess H. Marcus and LeighAnn H. Forsyth, Brown University
Center for Behavioral and Preventive Medicine, The Miriam
Hospital, Providence, Rhode Island; Patricia M. Dubbert, Veterans
Affairs Medical Center, Jackson, Mississippi; Thomas L. McKenzie, Department of Exercise and Nutritional Sciences, San Diego
State University; Elaine J. Stone, National Heart, Lung, and Blood
Institute, Bethesda, Maryland; Andrea L. Dunn and Steven N.
Blair, Cooper Institute for Aerobics Research, Dallas, Texas.
We thank Regina Traficante, Barbara Doll, and Lyn Robillard for
technical assistance in the preparation of this article.
Correspondence concerning this article should be addressed to
Bess H. Marcus, Brown University Center for Behavioral and
Preventive Medicine, The Miriam Hospital, 164 Summit Avenue,
Providence, Rhode Island 02906. Electronic mail may be sent to
[email protected].
Who Should Receive Intervention?
Definitions, Criteria, and Prevalence of Physical
Activity Behavior Change
All individuals older than 2 years benefit from incorporating at least 30 min of moderate- to vigorous-intensity
physical activity into their daily lives (USDHHS, 1996).
Before pubescence, most children seem to be naturally
active, and their physical activity is often enhanced through
physical education classes, youth sports, and recreational
activities. As a result, children tend to be the most active
segment of the U.S. population. However, physical activity
levels begin to decline at about 6 years of age and continue
to decline throughout the life cycle (Malina, 1996). Nearly
half of America's youth (ages 12-21 years) are not vigorously active on a regular basis. Physical inactivity is more
32
SUPPLEMENTAL ISSUE: PHYSICAL ACTIVITY MAINTENANCE
33
Attempts to change physical activity behavior have not
been officially defined. In various studies, indicators of
progression toward physical activity adoption have included
advanced stage of motivational readiness for physical activity adoption (e.g., Calfas et al., 1996; Dunn et al., 1997),
increased intention to be physically active (e.g., Wimbush,
MacGregor, & Fraser, 1998), and increases in actual physical activity behavior (e.g., A. C. King, Haskell, Young, Oka,
& Stefanick, 1995). When attempting to adopt physical
activity, many individuals appear to go through various
stages, often including the resumption of a sedentary
lifestyle, before activity is readopted and maintenance
occurs (Sallis & Hovell, 1990; USDHHS, 1996). No systematic data are available for prevalence of attempts to change
physical activity in the U.S. population.
occur when a previously sedentary individual meets Centers for
Disease Control (CDC)/ACSM recommendations for regular
physical activity for at least 6 months (Pate et al., 1995).
No national studies have been conducted to examine the
prevalence rates of successful change in physical activity
without formal intervention. However, some data do suggest
that intensity of physical activity is a factor in its adoption
and maintenance for adults (Dishman & Buckworth, 1996;
USDHHS, 1996). In a study examining moderate- and
vigorous-intensity physical activity in adults over a 1-year
period, more men than women were currently vigorously
active or in the process of adopting vigorous activity.
Approximately equal numbers adopted and quit vigorous
exercise across both genders. However, both men and
women were more likely to adopt and maintain moderateintensity activity (Sallis et al., 1986).
Preliminary analyses were conducted to examine maintenance of activity in a six-visit cohort (approximately 1 year
between visits) of 4,827 men and 1,106 women who visited
the Cooper Clinic from 1979 to 1997 and who were initially
healthy (Marcus, Cheng, Dunn, & Blair, 1999). Activity was
defined as regular weekly participation in at least one
exercise activity or sport in the preceding 3 months (Kohl,
Blair, Paffenbarger, Macera, & Kronefeld, 1988). If men
were sedentary at the first visit, 27% were found to remain
sedentary at all five follow-up visits, whereas 9% were
found to become active and remain active at all five
follow-up visits. For women who were sedentary at the first
visit, 49% remained sedentary at all five follow-up visits,
and only 5% of initially sedentary women became active and
remained active at all five follow-up visits. If men were active at
the first visit, 7% became sedentary and 26% remained active at
all five follow-up visits. However, if women were active at the
first visit, 2% became sedentary and 13% remained active at all
five follow-up visits. These data suggest that men have a greater
likelihood of maintaining their activity compared with women.
Also women seem far more likely to remain sedentary compared
with men. The sample consisted of primarily well educated (80%
college graduates) Caucasian individuals; further studies are
needed to address whether these results are generalizable to other
population groups.
Interventions designed to improve rates of successful
change do appear helpful. A meta-analysis examining physical activity interventions to improve physical activity adoption found that success rates improve from 50 to 67% after
some types of physical activity interventions (Dishman &
Buckworth, 1996). Effect sizes did not differ according to
gender, race, or age, although they were greater among
healthy samples compared with patient groups. Interventions using behavior modification strategies, emphasizing
lower intensity activity, and using a mediated delivery
approach were found to be most effective. In summary,
physical activity interventions can successfully increase
rates of successful change.
Criteria for Successful Change
Successful Maintenance
There are no established criteria for successful change in
children. For adults, a successful change is typically said to
A criterion for successful maintenance has not been
officially established. Intervention studies typically operation-
prevalent among girls than boys (13.8% vs. 7.3%), among
African American youth than Caucasian youth (15.3% vs.
9.3%), and among African American girls than Caucasian
girls (21.4% vs. 11.6%; USDHHS, 1996). Physical activity
declines dramatically during adolescence, when active environments such as physical education and youth sports
become less available and when school, work, and less
active leisure pursuits become more prominent. Therefore,
the teenage years may be a critical period for intervention
(Stone, McKenzie, Welk, & Booth, 1998; USDHHS, 1996).
The recommended level of physical activity for adults is
the accumulation of 30 min or more of moderate-intensity
physical activity (e.g., brisk walking) on 5 or more days each
week (Pate et al., 1995) or 20 to 60 min of vigorous-intensity
physical activity (e.g., jogging) at least 3 days per week
(American College of Sports Medicine, [ACSM], 1990).
However, more than 60% of American adults are not
meeting either criterion, and approximately 25% of all
adults are not active at all (USDHHS, 1996). Certain
segments of the U.S. adult population tend to be more
sedentary than others and, therefore, are in greater need of
intervention. Specifically, sedentary behavior is more prevalent for women (30.7% vs. 26.5% of men), older adults
(38.2% of men 75 years or older and 50.5% of women 75
years or older vs. 18.9% and 25.4% of men and women,
respectively, in the 18- to 29-year age group), the less
educated (46.5% of individuals younger than 12 vs. 17.8%
of college graduates), the poor (41.5% of the population
with a yearly income <$10,000 vs. 17.8% of those with
incomes > $50,000), and ethnic minorities (African Americans: 38.5%; Hispanics: 34.8%; Caucasians: 26.8%; Centers
for Disease Control, 1992). People with disabilities and
chronic illness are also less likely than those without
disabilities to report regular moderate physical activity
(27.2% vs. 34.4%) and less likely to report regular vigorous
activity (9.6% vs. 14.2%; USDHHS, 1996).
Definition of Attempts to Change
34
MARCUS ET AL.
alize maintenance as engaging in regular physical activity
for at least 6 months after cessation of intervention (e.g.,
Dunn et al., 1999); similarly, individuals who increase their
activity on their own (without participating in a formal
intervention) and perform regular physical activity for at
least 6 months are viewed as successful maintainers. Typically, researchers in this area focused on successful maintenance of physical activity rather than successful maintenance of physical activity change. Thus, individuals who are
currently engaging in regular activity and have always
engaged in physical activity are considered successful
maintainers. This differs from the way in which successful
maintenance is conceptualized in the area of weight control
and smoking, in which the focus is on maintenance of
change.
The prevalence of successful maintainers for either criterion is unknown. In national surveys such as the National
Health Interview Survey (National Center for Health Statistics, [NCHS], Benson & Marano, 1994), the Behavioral Risk
Factor Surveillance System (CDC, 1992), and the Third
National Health and Nutrition Examination Survey (NCHS,
1994), the prevalence of regular activity was assessed but
not the length of time for which those surveyed were
regularly active. As a result, the prevalence of maintenance
of regular physical activity was not determined. Current
self-report measures of physical activity behavior often
assess a brief interval of time (e.g., last 7 days or previous 2
weeks), and it is not clear how well this represents people's
general activity levels over several months or years.
Lapse-Relapse Curve
Early exercise adherence studies, conducted mostly with
high participants at risk for cardiovascular disease (CVD),
suggested that a 50% dropout rate was not uncommon.
Looking back on these earlier studies, we do not know the
extent to which these findings reflect the designs of the trials,
the types of participants, and the frequency of measurements
rather than the influence of other variables such as health
complications or declining motivation for exercise. The use
of a dichotomous measure for adherence also limited
interpretation of the data because "dropout" from a supervised program did not always correspond to cessation of
exercise. Moreover, this dropout rate may reflect the fact that
many of these earlier studies focused on structured exercise
programs rather than a lifestyle approach to physical activity. More recent studies are more likely to report percentage
of adherence to specified criteria (Dunn et al., 1999; A. C.
King et al., 1995; Martin & Dubbert, 1982) to specify
whether adherence includes unsupervised home-based exercise and to report findings based on intention to treat.
Although adherence has been measured in different ways
and at different intervals across studies, more recent data
from trials, including home-based interventions, are consistent with earlier conclusions that adherence decays over
time. What has become clearer is that subgroups can be
identified that have widely varying rates of adherence. For
example, in the Stanford-Sunnyvale Health Improvement
Project (SSHIP) study, high adherers (those randomized to
home-based exercise who had low levels of stress) continued to complete 70% or more of their prescribed exercise at
2 years, whereas low adherers (those randomized to structured exercise who had a high body mass index) had a much
lower level of adherence in the early phase of the study and
were completing only about 20% of their prescribed exercise
at 2 years (A. C. King et al., 1997). More studies of this
nature will help greatly in understanding when and why
people become less active over time.
Furthermore, we know very little about the impact of
activity interruptions on long-term adherence. The relapse
prevention model was developed in the context of attempting to understand the psychosocial determinants of addictive
behaviors (Marlatt & Gordon, 1985). In this model, inadequate coping skills for difficult or "high-risk" situations
contribute to the return to unhealthy behavior patterns.
Instead of the "lapse" becoming an opportunity to learn
better coping, all too often an "abstinence violation effect"
occurs, in which guilt and perceived loss of control lead to
total relapse. Consistent with the model, Simkin and Gross
(1994) found that college women who listed fewer coping
strategies for likely problem situations were more likely to
experience a lapse from attendance at an aerobics class.
However, failure to exercise during any given period of time
is not a single identifiable event analogous to violating an
"abstinence" rule in substance abuse recovery (Dubbert &
Stetson, 1995). For example, when should failure to exercise
be perceived as a lapse or relapse? Dubbert and Stetson
(1995) found that community exercisers' perceptions of
whether they had "dropped out" of exercise were significantly related to both the amount of time they failed to
exercise and their previous exercise experience. Those who
had been exercising regularly for the longest time before
their period of inactivity reported longer periods of inactivity before they perceived themselves as having dropped out.
These results suggest that studies of exercise lapse and
relapse in adults as well as adolescents need to assess
participants' perceptions.
Observational data suggest that, at least with vigorous
exercise, interruptions in exercise are the rule rather than the
exception. In a study of exercise relapse in 7,135 YMCA
members, 81% had a lapse during the year (J. M. Jakicic,
personal communication, June 18, 1998). A lapse was
defined as not attending the YMCA for at least 7 consecutive
days. The average number of lapses per member was 4.8 per
year; 36 days was the average length of the lapse. These data
are currently undergoing additional analysis to identify
when individuals are most likely to experience a lapse.
Another observational study found that 20% of regular
exercisers reported experiencing a relapse (defined as no
exercise for at least 3 months) three or more times, 20%
reported one or two relapses, and 60% reported no relapses
(Sallisetal., 1990).
Intervention Studies to Enhance Physical
Activity Maintenance
We now examine intervention studies that included at
least 6 months of follow-up data collected after cessation of
SUPPLEMENTAL ISSUE: PHYSICAL ACTIVITY MAINTENANCE
the active intervention so that maintenance of physical
activity after the intervention could be assessed. Different
measures of physical activity behavior were used across
studies, making it difficult to make interstudy comparisons.
Given the paucity of reports on maintenance and the
inconsistent measurement methods across studies, our goal
is to highlight some of the key studies of physical activity
maintenance in youth, healthy adults, and patient populations rather than to provide a comprehensive review (reviews of physical activity intervention studies segmented by
population, setting, and type of intervention can be found in
the American Journal of Preventive Medicine, 1998, Volume
16). Often studies with evidence of successful maintenance
did not report the specific intervention strategies used to
achieve maintenance, but we attempt to identify critical
intervention components when possible.
Youth Studies
Most youth intervention studies have been conducted in
school environments, particularly in elementary schools.
The most common strategy has been to modify physical
education (PE) classes. The most effective school PE
interventions entail an active curriculum, staff development
(i.e., in-service training), and on-site follow-up (McKenzie
et al., 1996; McKenzie, Sallis, Kolody, & Faucette, 1997;
Stone et al., 1998). Only a few studies included substantial
postintervention follow-ups with youth cohorts (Stone et al.,
1998). The longest follow-ups were 12, 7, and 3 years,
respectively, for the Oslo Youth Study (Klepp, Oygard, Tell,
& Vellar, 1993; Tell & Vellar, 1987), the Class of 1989 Study
(Kelder, Perry, & Klepp, 1993), and the Child and Adolescent Trial for Cardiovascular Health (CATCH; Luepker et
al., 1996; McKenzie et al., 1996; Nader et al., 1999). All
three showed declining effects over time but still reported
significant increases in physical activity for intervention
students versus the control students.
CATCH was the most extensive study of maintenance and
was the first multicenter randomized school-based research
study to use the fundamentals of clinical trials (Stone et al.,
1996). CATCH tested the effectiveness of changes in PE
classes, school food service, classroom curricula, family
activities, and school policies related to cardiovascular
health (1991-1994). Ninety-six elementary schools in four
states were randomized to intervention or control conditions.
The baseline cohort comprised 5,106 ethnically diverse third
graders who were monitored through fifth grade during the
main trial. The students were from California, Louisiana,
Minnesota, and Texas, and almost half were boys (51.8%).
The racial-ethnic groups represented Caucasian (69.1%),
Hispanic (13.9%), African American (13.2%), and others
(3.8%).
Results from systematic analysis of 2,096 PE lessons
indicated students in intervention schools engaged in more
moderate- to vigorous-intensity physical activity during PE
lessons than those in control schools (51.9% vs. 42.3% of
lesson time, p = .002). This represented a 39% increase in
physical activity from baseline for intervention schools,
whereas controls increased by 23%. In addition to school
35
level measures of PE, total daily activity was assessed in
fifth grade. Intervention students reported significantly more
vigorous activity than controls (Luepker et al., 1996; McKenzie et al., 1996).
The CATCH Cohort Tracking Study (1995-1998) was
conducted to assess the differences through eighth grade in
physical activity, diet, and related health indicators of
CATCH students. Students were assessed in sixth, seventh,
and eighth grades. Seventy-three percent (3,714) of the
initial cohort of 5,106 students participated in the follow-up
tracking study (Nader et al., 1999). The 3-year follow-up,
without further intervention, showed that the behavioral
changes initiated in the upper elementary school years were
maintained through early adolescence for self-reported physical activity and dietary behaviors (Nader et al., 1999).
Percentage differences for vigorous activity between intervention and control groups were maintained even though the
absolute levels of vigorous activity minutes per day declined
in both groups. At the end of the CATCH trial during fifth
grade, the significant difference reported for daily minutes of
vigorous activity between intervention and control students
was 13.6 min (23% of the control mean). This was a
substantial difference equal to more than 1.5 hr (92.3 min) of
vigorous activity per week. At the end of sixth grade, the
difference was 21.1% (11.2 min); at the end of seventh
grade, 26.5% (10.8 min); and at the end of eighth grade,
29.1% (8.8 min; Nader et al., 1999). More than 8 min per
day equals 1 hr additional vigorous activity per week, even
with the decline in maintenance 3 years after intervention. A
decline in activity participation with age, especially during
adolescence, has been previously documented (Malina,
1996; Stone et al., 1998; USDHHS, 1996) and points to the
need for interventions during middle school.
Healthy Adult Studies
Interventions with healthy adults included different approaches, among them structured activity, home-based programs, lifestyle activity programs, intermittent exercise
bouts, and environmental changes. Programs have been
carried out in fitness centers, community settings, physicians' offices, and workplaces (e.g., Dishman & Duckworth,
1996). Although more than 100 intervention studies with
healthy adults have been conducted, very few studies
included at least 6-months of follow-up data on physical
activity maintenance. Two key studies that included follow-up through 24 months are highlighted.
Choice of physical activity format and intensity appears to
be a key factor in long-term exercise participation for adults.
The 2-year SSHEP trial was the first to examine people's
preference for structured home-based moderate and vigorous activity versus structured group-based vigorous activity
(A. C. King et al., 1995). Adults aged 50 to 65 years were
randomized to a high-intensity structured exercise group
held in a community senior center and a community college
(3 days/week), a high-intensity telephone-supervised homebased physical activity program (3 days/week), a moderateintensity telephone-supervised home-based physical activity
program (5 days/week), or an assessment-only condition.
36
MARCUS ET AL.
All intervention groups were given an ACSM exercise
prescription for meeting a target heart rate criterion.
Intervention components in the telephone-supervised,
home-based groups included physical activity assessment,
information giving, physical activity instruction, physical
activity feedback, goal setting, support for activity, and
general support. When compared with the traditional groupbased exercise program, the home-based programs focusing
on either moderate- or vigorous-intensity activity had significantly greater adherence at the 1-year assessment. After 2
years of active intervention, however, the high-intensity
home-based program had higher adherence rates than the
lower-intensity home-based program. The authors speculated that it is more difficult for individuals to schedule
exercise for 5 days as opposed to 3, indicating the need for
further study of interventions for promoting moderateintensity physical activity. Other analyses found the participants with the greatest probability of exercise maintenance
at the 2-year assessment tended to be those who were less
educated, assigned to supervised home-based interventions
(higher or lower intensity), less stressed, and less fit at
baseline (A. C. King et al., 1997).
In response to low prevalence rates of regular vigorousintensity physical activity and the accumulated evidence
from epidemiological and exercise training studies, organizations such as the American Heart Association (Fletcher et al.,
1992), Centers for Disease Control and Prevention, and
ACSM (Pate et al., 1995) issued public health recommendations for accumulating at least 30 min of moderate-intensity
activity on most, and preferably all, days of the week. These
public health recommendations resulted in the development
of alternatives to structured, prescriptive exercise approaches, including multiple short bouts of moderateintensity activity and lifestyle physical activity.
Project Active was a 2-year randomized trial that compared a lifestyle physical activity intervention with a traditional structured exercise program (Dunn et al., 1997,1999).
Both programs entailed 6 months of active treatment and 18
months of maintenance intervention. The lifestyle group
members met for hourly meetings each week that gradually
decreased in frequency beginning at 4 months. By learning
behavioral skills, participants were encouraged to select a
variety of moderate to vigorous activities and to integrate
them into their daily routine. The structured group participants were given a 6-month membership to a state-of-the-art
fitness center and met with an exercise trainer, working up to
5 days a week of activity. At 6 months, both groups became
significantly more active (Dunn et al., 1998). Although the
groups did not differ on meeting CDC/ACSM criteria and
both groups significantly increased fitness, the structured
group was more physically fit than the lifestyle group. At 24
months, after 18 months of minimal follow-up intervention,
20% of participants in each group were meeting or exceeding CDC/ACSM criteria, and both groups still showed
significant improvement in energy expenditure and cardiorespiratory fitness from baseline (Dunn et al., 1999). This
indicates that a behaviorally based lifestyle approach can
provide a useful alternative in meeting individual and public
health recommendations for physical activity. In addition,
the 24-month assessment indicated that, although both
groups declined in physical activity and cardiorespiratory
fitness during the 18 months after active intervention, there
was a greater decline in the structured exercise group,
suggesting that this group was not able to maintain its
physical activity routine as effectively as the lifestyle group.
Additionally, regression analyses indicated that, for all
outcomes, those who responded that they were regularly
active 70% or more of the time during the 18-month
follow-up phase had at least twice as much improvement
compared with those who did not.
An important component of the lifestyle group was the
curriculum, developed to target specifically cognitive and
behavioral strategies for change based on the stages of
change model (Prochaska & DiClemente, 1983) and socialcognitive theory (Bandura, 1986). Analyses indicated that
change in some of these strategies (i.e., enlisting social
support, rewarding yourself, reminding yourself) during the
first 6 months predicted physical activity behavior at 24
months. Further analyses of these strategies at 24 months
showed that the 6-month change in each behavioral strategy
was predictive of meeting the CDC/ACSM criterion for
physical activity at 24 months. Thus, it appears that a
behavioral-based lifestyle physical activity intervention increases the use of these strategies for change, and this
increase is associated with maintaining physical activity
(Dunn et al., 1999).
From these two studies and other trials targeting healthy
adults, intervention components associated with better maintenance of physical activity appear to be home-based
programs or the option of such a program; a mediated
delivery approach, mat is telephone (e.g., Chen et al., 1998;
A. C. King, Taylor, Haskell, & DeBusk, 1988; A. C. King et
al., 1995), mail (Fries, Bloch, Harrington, Richardson, &
Beck, 1993; A. C. King, Frey-Hewitt, Dreon, & Wood,
1989), and print materials (Brown & Lee, 1994; Mayer et al.,
1994; Reid & Morgan, 1979); interventions delivered in
community settings (Osier & Jespersen, 1993); and selfmanagement instruction (i.e., frequent self-monitoring, goal
setting; Kriska et al., 1986). Maintenance interventions such
as frequent contact with participants during the maintenance
phase seems to be important, although it has yet to be
demonstrated what needs to happen during contacts, how
often they need to occur, and at what point intervention is no
longer necessary.
Cardiac Rehabilitation and Hypertension Studies
Some research on maintenance of physical activity is also
available for patient populations from cardiac rehabilitation
programs and hypertension prevention and treatment trials.
Data from pulmonary rehabilitation programs are not discussed here because they only provide up to 6 months
follow-up, which does not permit comparison with studies
of CVD or healthy populations. A review of CVD secondary
prevention studies located 24 studies with 12 or more
months of follow-up (Simons-Morton, Calfas, & Oldenburg,
1998). In most of these studies, the intervention was initiated
in a clinical setting and involved vigorous exercise three
SUPPLEMENTAL ISSUE: PHYSICAL ACTIVITY MAINTENANCE
times a week. Some studies included efforts to establish
activity in community settings. In 14 studies, participants
were postmyocardial infarction patients, whereas in other
studies, participants had some form of coronary heart
disease. Participants in most studies were men. Ethnicity and
socioeconomic data were often not available. It also should
be noted that the majority of these studies focused on
multiple risk factors; however, the following discussion
pertains to physical activity findings only.
Effective components in studies that found improved
fitness or superior adherence at 12 months, compared with
control treatment groups, included supervision of exercise,
loaning equipment, more frequent contact with program
staff, inclusion of a behavioral component, promotion of
moderate-intensity activity, and specific maintenance interventions. Eighteen studies used the ACSM (1990) exercise
prescription guidelines, and two used the moderate-intensity
recommendation for physical activity (Pate et al., 1995).
Several studies reported participation at greater than or equal
to 50% at 12 months, but early dropouts were typically
excluded from these analyses. Two of three studies with
long-term follow-up reported that participation continued at
50% or greater at 2 years. Interpretation of long-term
adherence in the cardiac rehabilitation literature is difficult,
however, because investigators in early studies did not
report findings based on intent to treat, and several welldesigned studies reported only overall maintenance averaged across the entire follow-up period. Omish et al. (1990)
reported excellent adherence across a 1-year trial requiring a
minimum of 3 hours per week of exercise in selected
coronary artery disease (CAD) patients. Haskell et al. (1994)
found improved fitness across 4 years of study follow-up for
CAD patients in a multiple risk factor reduction program,
including physical activity counseling to increase daily
activity by walking, household chores, and stair climbing as
well as a tailored endurance training program. These results
suggest it is feasible to achieve clinically important adoption
and maintenance rates in high-risk CVD patients, although
adherence decays over time, especially when there are no
maintenance interventions.
In a more recent study, Friedman, Williams, and Levine
(1997) examined compliance and efficacy of cardiac rehabilitation and risk factor modification in the medically indigent.
Thirty-six indigent patients were compared with 29 medically insured patients in a 12-week rehabilitation program of
three weekly sessions. Individualized instructions were
given at the end of 12 weeks, including a plan for maintenance at home (e.g., mall walking, stair climbing, neighborhood facilities). By self-report, the percentage of adhering
patients was greater than 90% in both groups at the
12-month follow-up, and improvement in submaximal work
capacity was maintained. Success was attributed to a small
intimate program, a creative approach to overcoming transportation problems, and an individualized approach.
Increases in aerobic physical activity, especially moderateintensity walking, have often been specifically encouraged
in hypertension prevention and treatment trials. These
physical activity interventions are typically linked to weight
reduction interventions, and individual counseling by a
37
nutritionist is the most common intervention modality. More
recent trials also used group classes. The most detailed
report of the results of physical activity interventions in
hypertension trials is available from the Treatment of Mild
Hypertension Study (Elmer et al., 1995). More than 900 men
and women were randomized to lifestyle intervention plus
placebo or one of five drug treatments. The lifestyle
intervention began with 6 months of intensive treatment,
including 13 individual or group sessions with nutritionists.
Participants were encouraged to increase energy expenditure
through unsupervised home-based activity. Specific intervention components included individual counseling every 6 to
12 weeks throughout follow-up, newsletters on physical
activity and nutrition, activity outings and competitions,
daily self-monitoring, unsupervised physical activity, behavior modification (e.g., stimulus control, goal setting, cognitive restructuring, identification of high-risk situations), and
an invitation to spouses to attend sessions. Self-reported
energy expenditure increases of 86% for men and 81% for
women were maintained at 2 years. Increases of 50% over
baseline were maintained at 4 years without maintenance
intervention. Findings from this study suggest that people at
risk because of elevated blood pressure can also be assisted
to increase their physical activity and maintain a change for
several years.
Multiple Risk Factors
Although many of the secondary prevention studies used
interventions targeting multiple health behaviors, in recent
years there has been great interest in understanding the
optimal ways to intervene in nonpatient populations with
multiple risk factors such as smoking, overweight, and
sedentary lifestyle and how maintenance across these different domains are related.
Some of the first multiple risk studies that included
comparison groups and follow-up assessment were community-wide cardiovascular risk reduction campaigns such as
the Stanford Five-City Project (Young, Haskell, Taylor, &
Fortmann, 1996) and the Minnesota Heart Health Program
(Luepker et al., 1994). Findings from these studies revealed
only modest improvements in physical activity participation,
which generally declined across years of follow-up assessment (Marcus, Owen, Forsyth, Cavill, & Fridinger, 1998).
However, in these studies, it is not clear how much
intervention effort was placed on physical activity relative to
other behaviors such as smoking cessation and weight loss.
In addition, stage of motivational readiness for change was
not addressed.
In a cross-sectional study, cognitive and motivational
factors were assessed in 332 smokers at two workplaces
(T. K. King, Marcus, Pinto, Emmons, & Abrams, 1996).
Findings showed that positive attitudes about physical
activity were significantly related to negative attitudes about
smoking. Self-efficacy to change one behavior was significantly related to self-efficacy to change another risk behavior. Smokers who were actively working on quitting smoking were significantly more confident in their ability to
exercise than smokers who were just thinking about quitting.
38
MARCUS ET AL.
Smokers who were exercising regularly were significantly
more confident in their ability to refrain from smoking.
The contribution of physical activity to weight loss and
weight maintenance is well established (National Institutes
of Health, National Heart, Lung, and Blood Institute,
[NHLBI], 1998; Pronk & Wing, 1994). A recent 18-month
trial examined the role of exercise prescription, specifically
that of accumulated physical activity, for achieving and
maintaining weight loss (Jakicic, Winters, Lang, & Wing,
1999). During weekly meetings, overweight women were
taught behavioral strategies to assist them in making healthful changes in their eating and exercise behaviors. In
addition, all women received a 1,200 to 1,500 kcal/day
eating plan, were instructed how to reduce fat intake to 20%
of their total calories, and were placed on a structured
exercise program that varied in whether exercise was
continuous or accumulated. Participants were randomized to
receive an exercise prescription for home-based physical
activity in long bouts, multiple daily short bouts, or short
bouts with the provision of home exercise equipment.
Participants were given the freedom to participate in activity
at times convenient for their lifestyle.
Results from baseline to 6 months showed that a similar
number of participants in each group were averaging at least
150 min of exercise per week, and no significant differences
between the groups were found. However, the groups
assigned to short exercise bouts or performing short exercise
bouts with home equipment were averaging approximately
180 min of exercise per week, whereas the group assigned to
long exercise bouts was averaging approximately 150 min
per week. Despite this difference in exercise between the
groups, there was no difference in weight loss. All groups
showed a decrease in weight of approximately 20 pounds.
From Months 7 to 12, exercise participation decreased in all
groups. The long bout group averaged approximately 110
min of exercise per week, whereas the short bout and short
bout with equipment groups averaged 130 to 140 min of
exercise per week. Despite the decrease in the number of
individuals maintaining an average of 150 min of exercise
per week in each group, a subset of participants did maintain
at least 190 min of exercise per week during Months 7 to 12.
This group maintained their weight loss (approximately 20
pounds), whereas those who did not achieve an average of
150 min of exercise per week regained approximately 15 to
30% of the weight they had lost.
Another study investigated whether participation in vigorous exercise improved the efficacy of a cognitive-behavioral
smoking cessation treatment program for initially sedentary
women smokers (Marcus, Albrecht, et al., 1999). This trial
compared women assigned to a regular, on-site, supervised
vigorous physical activity program with a contact control
group. All participants also participated in 12 weekly
group-based cognitive-behavioral smoking cessation sessions. Participants randomized to exercise achieved significantly higher levels of continuous abstinence during treatment compared with those randomized to contact control,
and these findings held through 12 months of follow-up. In
addition, the women in the exercise condition who quit
smoking gained approximately half as much weight as their
peers in contact control.
Although the results of Marcus, Albrecht, et al. (1999) are
compelling, little is known, using rigorous designs, about
whether physical activity directly facilitates improvements
in other health behaviors. Additionally, these two studies
illustrate the importance of considering the ultimate goals
for each targeted behavior. Although the goal for most
physical activity interventions is to assist people in meeting
the CDC/ACSM criterion of 150 min of activity per week,
Jakicic's study indicated that the participants who were able
to maintain their weight loss long term were exercising
about 190 min per week. Thus, for certain subgroups of the
population, minimum public health recommendations may
not be adequate for maintaining some other health outcomes. Intervention strategies need to take these factors into
account when targeting multiple risk behaviors.
Conclusions and Future Directions
The physical activity intervention literature suggests
cause for optimism but much to learn concerning where we
go from here in meeting public health challenges across the
life span. To understand and improve maintenance of
activity, it will be important to conduct more studies with
maintenance intervention that monitor people through at
least 24 months of follow-up like the SSffiP (A. C. King et
al., 1995) and Project Active trials (Dunn et al., 1997,1999).
Additionally, trials are needed that monitor participants for 5
to 10 years so that patterns of maintenance of physical activity
can be established. Moreover, there is an urgent need for
consistent measurement of physical activity behavior so that
findings from different investigations will be more comparable.
It appears to be important to explore differences in
maintenance among various age groups because there seem
to be points of vulnerability for increased sedentary behavior
at different developmental stages. For example, girls approaching puberty show increases in television watching
(Andersen, Crespo, Bartlett, Cheskin, & Pratt, 1998) and a
decline in physical activity (USDHHS, 1996). College
students making the transition into the workforce seem to be
at high risk for becoming sedentary as suggested by notable
increases in body weight that tend to occur at this time
(Williamson, Kahn, Remington, & Anda, 1990). Current
studies suggest that there are different challenges for shortterm versus long-term behavior change. Some behavioral
strategies may be more important for the maintenance phase
compared with initiation of physical activity. In this regard,
it is critical that future studies provide information on the
greatest barriers to the initiation of activity and short-term,
and long-term maintenance of physical activity behavior. We
have yet to discover the pattern of starting and stopping
activity in which most people engage, although data reveal
that people start and stop exercising repeatedly. Once these
patterns are better understood, it is important to use this
information to maximize the effectiveness of our interventions. Additionally, it is essential to investigate successful
strategies for behavior change by gender, age, ethnicity,
baseline activity, and risk status. "One-size-fits-all" pro-
SUPPLEMENTAL ISSUE: PHYSICAL ACTIVITY MAINTENANCE
grams are rarely as effective as programs that tailor treatment to at least some aspects of the individual or group
(Marcus, Bock, et al., 1998).
Research Recommendations
1. Examine the predictors, mediators, and correlates of
maintenance of physical activity over time periods up to 5
years and in diverse populations.
(a) Investigate factors associated with differential patterns of adoption and maintenance of physical activity.
For example, are there critical periods when physical
activity becomes part of a lifestyle? In the absence of
intervention, what is the natural history of change?
(b) Determine factors associated with maintenance
after an intervention.
(c) Compare individuals who maintain physical activity
with those who relapse.
(d) Develop a registry to study individuals who are
successful at long-term physical activity participation.
(e) Conduct follow-up assessments of participants
previously involved in physical activity intervention trials
to examine their long-term physical activity participation.
2. Design and evaluate interventions to promote maintenance of physical activity behavior.
(a) Conduct randomized, controlled trials to determine
the delivery channels that are most effective and practical
for improving long-term maintenance of physical activity
behavior. This should include research on use of print
materials, telephone intervention, Internet and electronic
mail technologies, and face-to-face interventions. Issues
related to the amount of intervention needed and the
interaction between delivery channel and participant
characteristics should be addressed.
(b) Test maintenance intervention delivery in various
settings (e.g., physician offices, work sites, school settings) for different subgroups of individuals such as
children, ethnic minorities, and the elderly, and for
primary versus secondary prevention.
(c) Determine the intensity, frequency, duration, and types
of physical activity that maximize long-term adherence.
(d) Examine behavioral and cognitive strategies to promote
long-term exercise adherence.
3. Explore the usefulness of various theoretically based
intervention models for conceptualizing and maintaining
physical activity behavior change.
(a) What is the potential of models such as behavioral
choice and social-ecological theory for designing and
testing the effectiveness of maintenance interventions?
(b) What other theoretical models describe the process
of physical activity maintenance?
(c) Why is increasing physical activity helpful in
maintaining other types of health behavior changes?
4. Evaluate early influences on physical activity adoption
and maintenance.
(a) Conduct studies with children to learn the critical
periods for physical activity adoption and maintenance.
(b) Examine the influence of parents, family, and
39
school PE and environment on the promotion of physical
activity.
5. Develop methods to study patterns of physical activity
and energy expenditure appropriate for adult and youth
populations.
(a) Explore various technologies to measure the accumulation of moderate-intensity and vigorous-intensity
physical activity in adults because no national data
currently exist.
(b) Standardize definitions and methods of assessing
maintenance for use in national surveys.
(c) Validate existing measures of physical activity and
develop new validated measurement tools as technology
advances.
6. Develop and evaluate the effectiveness of environmental interventions.
(a) Conduct quasi-experimental studies in workplaces,
schools, and other defined settings or groups within
communities.
(b) Design policy and environmental change to enhance maintenance of physically active lifestyles at the
state and national levels.
Additional Recommendations to Facilitate Progress
The following additional recommendations should facilitate implementing the prior research recommendations: (a)
Develop initiatives and funding mechanisms to study maintenance issues that would allow for longer follow-up,
including additional support for existing grants; (b) establish
postdoctoral training mechanisms to promote the study of
physical activity maintenance; (c) find ways to study the
behavioral contributions of multiple risk factors and interventions, which may require joint effort by several sponsoring
agencies (e.g., NHLBI, National Institute for Diabetes and
Digestive and Kidney Diseases, National Cancer Institute)
to fund large multiple-risk factor studies in various settings
testing different delivery channels; and (d) foster research
recommendations and dissemination of findings through
conferences on physical activity measures and psychometrics of instruments, scientific roundtables (e.g., ACSM) on
maintenance of effects of physical activity interventions, and
joint researcher and practitioner meetings.
References
American College of Sports Medicine. (1990). American College
of Sports Medicine Position Stand. The recommended quantity
and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness in healthy adults. Medicine and
Science in Sports and Exercise, 22(2), 265-274.
Andersen, R. E., Crespo, C. J., Bartlett, S. J., Cheskin, L. J., &
Pratt, M. (1998). Relationship of physical activity and television
watching with body weight and level of fatness among children.
JAMA: Journal of the American Medical Association, 279.
938-942.
Bandura, A. (1986). Social foundations of thought and action: A
social cognitive theory. Englewood Cliffs, NJ: Prentice Hall.
Bouchard, C., Shephard, R., & Stephens, T. (1994). Consensus
statement. In C. Bouchard, R. Shephard, & T. Stephens (Eds.),
Physical activity, fitness, and health: International proceedings
40
MARCUS ET AL.
and consensus statement (pp. 9-76). Champaign, IL: Human
Kinetics Books.
Brown, W. J., & Lee, C. (1994). Exercise and dietary modification
with women of non-English speaking background: A pilot study
with Polish-Australian women. International Journal of Behavioral Medicine, 1(3), 185-203.
Calfas, K. J., Long, B. J., Sallis, J. R, Woolen, W. J., Pratt, M., &
Patrick, K. (1996). A controlled trial of physician counseling to
promote the adoption of physical activity. Preventive Medicine,
25(3), 225-233.
Centers for Disease Control. (1992). 7992 BRFSS summary
prevalence report. Atlanta, GA: Department of Health and
Human Services, Public Health Service, Centers for Disease
Control, National Center for Chronic Disease Prevention and
Health Promotion.
Chen, A. H., Sallis, J. R, Castro, C. M., Lee, R. E., Hickmann,
S. A., Williams, C., & Martin, J. E. (1998). A home-based
behavioral intervention to promote walking in sedentary ethnic
minority women: Project WALK. Women's Health and Research
on Gender, Behavior, and Policy, 4, 19-39.
Dishman, R. K., & Buckworth, J. (1996). Increasing physical
activity: A quantitative synthesis. Medicine and Science in
Sports and Exercise, 28, 706-719.
Dubbert, P. M., & Stetson, B. A. (1995). Exercise and physical
activity. In A. J. Goreczny (Ed.), Handbook of health and
rehabilitation psychology (pp. 255-274). New York: Plenum.
Dunn, A. L., Garcia, M. E., Marcus, B. H., Kampert, J. B., Kohl,
H. W, & Blair, S. N. (1998). Six-month physical activity and
fitness changes in Project Active, a randomized trial. Medicine
and Science in Sports and Exercise, 30, 1076-1083.
Dunn, A. L., Marcus, B. H., Kampert, J. B., Garcia, M. E., Kohl,
H. W, m, & Blair, S. N. (1997). Reduction in cardiovascular
disease risk factors: 6-month results from Project Active.
Preventive Medicine, 26, 883-892.
Dunn, A. L., Marcus, B. H., Kampert, J. B., Garcia, M. E., Kohl,
H. W, m, & Blair, S. N. (1999). Comparison of lifestyle and
structured interventions to increase physical activity and cardiorespiratory fitness: A randomized trial. JAMA: Journal of the
American Medical Association, 281, 327-334.
Elmer, P. J., Grimm, R., Jr., Laing, B., Grandits, G., Svendsen, K.,
Van Heel, N., Betz, E., Raines, J., Link, M., Stamler, J., &
Neaton, J. (1995). Lifestyle intervention: Results of the Treatment of Mild Hypertension Study (TOMHS). Preventive Medicine, 24(4), 378-388.
Pletcher, G. R, Blair, S. N., Blumenthal, J., Caspersen, C.,
Chaitman. B., Epstein, S., Palls, H., Froelicher, E. S., Froelicher,
V. R, & Pina, I. L. (1992). Statement on exercise: Benefits and
recommendations for physical activity programs for all Americans. Circulation, 86(1), 340-344.
Priedman, D. B., Williams, A. N., & Levine, B. D. (1997).
Compliance and efficacy of cardiac rehabilitation and risk factor
modification in the medically indigent. American Journal of
Cardiology, 79(3), 281-285.
Pries, J. R, Bloch, D. A., Harrington, H., Richardson, N., & Beck,
R. (1993). Two-year results of a randomized controlled trial of a
health promotion program in a retiree population: The Bank of
America Study. American Journal of Medicine, 94, 455-462.
Haskell, W. L., Alderman, E. L., Pair, J. M., Maron, D. J., Mackey,
S. R, Superko, H. R., Williams, P. T., Johnstone, I. M.,
Champagne, M. A., Krauss, R. M., & Parquhar, J. W. (1994).
Effects of intensive multiple risk factor reduction on coronary
atherosclerosis and clinical cardiac events in men and women
with coronary artery disease: The Stanford Coronary Risk
Intervention Project (SCRIP). Circulation, 89, 975-990.
Jakicic, J. M., Winters, C., Lang, W, & Wing, R. R. (1999). Effects
of intermittent exercise and use of home exercise equipment on
adherence, weight loss, and fitness in overweight women.
JAMA: Journal of the American Medical Association, 282,
1554-1560.
Kelder, S. H., Perry, C. L., & Klepp, K. I. (1993). Community-wide
youth exercise promotion: Long-term outcomes of the Minnesota Heart Health Program and the Class of 1989 Study. Journal
of School Health, 63, 218-223.
King, A. C., Frey-Hewitt, B., Dreon, D. M., & Wood, P. D. (1989).
Diet vs. exercise in weight maintenance: The effects of minimal
intervention strategies on long-term outcomes in men. Archives
of Internal Medicine, 149, 2741-2746.
King, A. C., Haskell, W. L., Young, D. R., Oka, R. K., & Stefanick,
M. L. (1995). Long-term effects of varying intensities and
formats of physical activity on participation rates, fitness, and
lipoproteins in men and women aged 50 to 65 years. Circulation,
9, 2596-2604.
King, A. C., Kiernan, M., Oman, R. R, Kraemer, H. C., Hull, M., &
Ann, D. (1997). Can we identify who will adhere to long-term
physical activity? Signal detection methodology as a potential
aid to clinical decision making. Health Psychology, 16, 380-389.
King, A. C., Taylor, C. B., Haskell, W. L., & DeBusk, R. R (1988).
Strategies for increasing early adherence to and long-term
maintenance of home-based exercise training in healthy middleaged men and women. American Journal of Cardiology, 61,
628-632.
King, T. K., Marcus, B. H., Pinto, B. M., Emmons, K. M., &
Abrams, D. B. (1996). Cognitive-behavioral mediators of changing multiple behaviors: Smoking and a sedentary lifestyle.
Preventive Medicine, 25, 684—691.
Klepp, K. L, Oygard, L., Tell, G. S., & Vellar, O. D. (1993). The
Oslo Youth Study: A 12 year follow-up study of a school-based
health education program. In Proceedings: Health behavior in
adolescents: Implications for prevention of coronary heart
disease (pp. 94-105). Bergen, Norway: University of Bergen.
Kohl, H. W, Blair, S. N., Paffenbarger, R. S., Jr., Macera, C. A., &
Kronefeld, J. J. (1988). A mail survey of physical activity habits
as related to measured physical fitness. American Journal of
Epidemiology, 127, 1228-1239.
Kriska, A. M., Bayles, C., Cauley, J. A., Laporte, R. E., Sandier,
R. B., & Pambianco, G. (1986). A randomized exercise trial in
older women: Increased activity over two years and the factors
associated with compliance. Medicine and Science in Sports and
Exercise, 18(5), 557-562.
Luepker, R. V., Murray, D. M., Jacobs, D. R., Jr., Mittelmark,
M. B., Bracht, N., Carlaw, R., Crow, R., Elmer, P., Pinnegan, J.,
Polsom, A. R., Grimm, R., Hannan, P. J., Jeffrey, R., Lando, H.,
McGovern, P., Mullis, R., Perry, C. L., Pechacek, T., Pirie, P.,
Sprafka, J. M., Weisbrod, R., & Blackburn, H. (1994). Community education for cardiovascular disease prevention: Risk factor
changes in the Minnesota Heart Health Program. American
Journal of Public Health, 84, 1383-1393.
Luepker, R. V., Perry, C. J., McKinlay, S. M., Nader, P. R., Parcel,
G. S., Stone, E. J., Webber, L. S., Elder, J. P., Feldman, H. A.,
Johnson, C. C., Kelder, S. H., & Wu, M. (1996). Outcomes of a
field trial to improve children's dietary patterns and physical
activity. The Child and Adolescent Trial for Cardiovascular
Health. CATCH Collaborative Group. JAMA: Journal of the
American Medical Association, 275, 768-776.
Malina, R. M. (1996). Tracking of physical activity and physical
fitness across the lifespan. Research Quarterly for Exercise and
Sport, 57, 48-57.
Marcus, B. H., Albrecht, A. E., King, T. K., Parisi, A. R, Pinto,
B. M., Roberts, M., Niaura, R. S., & Abrams, D. B. (1999). The
efficacy of exercise as an aid for smoking cessation in women: A
SUPPLEMENTAL ISSUE: PHYSICAL ACTIVITY MAINTENANCE
randomized controlled trial. Archives of Internal Medicine, 159,
1229-1234.
Marcus, B. H., Bock, B. C., Pinto, B. M., Forsyth, L. H., Roberts,
M. B., & Traficante, R. M. (1998). Efficacy of an individualized,
motivationally-tailored physical activity intervention. Annals of
Behavioral Medicine, 20(3), 174-180.
Marcus, B. H., Cheng, Y, Dunn, A. L., & Blair, S. N. (1999, June).
Maintaining activity: An epidemiological perspective. Paper
presented at the meeting of the American College of Sports
Medicine, Seattle, WA.
Marcus, B. H., Owen, N., Forsyth, L. H., Cavill, N. A., & Fridinger,
F. (1998). Physical activity interventions using mass media, print
media, and information technology. American Journal of Preventive Medicine, 15, 362-378.
Marlatt, G. A., & Gordon, J. R. (1985). Relapse prevention:
Maintenance strategies in addictive behavior change. New
York: Guilford Press.
Martin, J. E., & Dubbert, P. M. (1982). Exercise applications and
promotion in behavioral medicine: Current status and future
directions. Journal of Consulting and Clinical Psychology, 50,
1004-1017.
Mayer, J. A., Jermanovich, A., Wright, B. L., Elder, J. P., Drew,
J. A., & Williams, S. J. (1994). Changes in health behaviors of
older adults: The San Diego Medicare Health Project. Preventive
Medicine, 23, 127-133.
McKenzie, T. L., Nader, P. R., Strikmiller, P. K., Yang, M., Stone,
E. J., Perry, C. L., Taylor, W. C., Epping, J., Feldman, H. A.,
Luepker, R. V., & Kelder, S. H. (1996). School physical
education: Effect of the child and adolescent trial for cardiovascular health. Preventive Medicine, 25, 423—431.
McKenzie, T. L., Sallis, J. F, Kolody, B., & Faucette, N. (1997).
Long term effects of a physical education curriculum and staff
development program: SPARK. Research Quarterly for Exercise
and Sport, 65,280-291.
Nader, P. R., Stone, E. J., Lytle, L. A., Perry, C. L., Osganian, S. K.,
Kelder, S., Webber, L. S., Elder, J. P., Montgomery, D., Feldman,
H. A., Wu, M., Johnson, C., Parcel, G. S., & Leupker, R. V.
(1999). Three-year maintenance of improved diet and physical
activity: The CATCH cohort. Archives ofPediatric and Adolescent Medicine, 153, 695-704.
National Center for Health Statistics. (1994). Plan and operation of
the Third National Health and Nutrition Examination Survey,
1988-1994. (Vital and Health Statistics, Series 1, No. 32, DHHS
Publication No. [PHSS] 94-1308). Hyattsville, MD: U.S. Department of Health and Human Series, Public Health Services,
Centers for Disease Control and Prevention, National Center for
Health Statistics.
National Center for Health Statistics, Benson, V., & Marano, M. A.
(1994). Current estimates from the National Health Interview
Survey, 1992 (Vital and Health Statistics, Series 10, No. 189,
DHHS Publication No. [PHSS] 94-1517). Hyattsville, MD: U.S.
Department of Health and Human Series, Public Health Services, Centers for Disease Control and Prevention, National
Center for Health Statistics.
National Institutes of Health, National Heart, Lung, and Blood
Institute. (1998). Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults—The
evidence report. Obesity Research, 6 (1, Suppl. 2), 102S-155S.
Omish, D., Brown, S. E., Scherwitz, L. W., Billings, J. H.,
Armstrong, W. T, Ports, T. A., McLanahan, S. M., Kirkeeide,
R. L., Brand, R. J., & Gould, K. L. (1990). Can lifestyle changes
reverse coronary heart disease? The Lifestyle Heart Trial.
Lancet, 336, 129-133.
41
Osier, M., & Jespersen, N. B. (1993). The effect of a communitybased cardiovascular disease prevention project in a Danish
municipality. Danish Medical Bulletin, 40, 485-489.
Pate, R. R., Pratt, M., Blair, S. N., Haskell, W. L., Macera, C. A.,
Bouchard, C., Buchner, D., Ettinger, W, Heath, G. W, King,
A. C., Kriska, A., Leon, A. S., Marcus, B. H., Morris, J.,
Paffenbarger, R. S., Patrick, K., Pollock, M. L., Rippe, J. M.,
Saffis, J., & Wilmore, J. H. (1995). Physical activity and public health:
A recommendation from the Centers for Disease Control and
Prevention and the American College of Sports Medicine. JAMA:
Journal of the American Medical Association, 273,402-407.
Prochaska, J. O., & DiClemente, C. C. (1983). Stages and
processes of self-change of smoking: Toward an integrative
model of change. Journal of Consulting and Clinical Psychology, 51, 390-395.
Pronk, N. P., & Wing, R. R. (1994). Physical activity and long-term
maintenance of weight loss. Obesity Research, 2, 587-599.
Reid, E. L., & Morgan, R. W. (1979). Exercise prescription: A
clinical trial. American Journal of Public Health, 69, 591-595.
Sallis, J. F, Haskell, W. L., Fortmann, S. P., Vranizan, K. M.,
Taylor, C. B., & Solomon, D. S. (1986). Predictors of adoption
and maintenance of physical activity in a community sample.
Preventive Medicine, 15, 331-341.
Sallis, J. F., & Hovell, M. F. (1990). Determinants of exercise behavior.
In J. O. Holloszy & K. B. Pandolf (Eds.), Exercise and sport sciences
review (pp. 307-330). Baltimore: Williams & Wilkins.
Saffis, J. F, Hovell, M. F., Hofstetter, C. R, Elder, J. P., Faucher, P., Spry,
V. M., Barrington, E., & Hackley, M. (1990). Lifetime history of
relapse from exercise. Addictive Behaviors, 15, 573-579.
Simkin, L. R., & Gross, A. M. (1994). Assessment of coping with
high-risk situations for exercise relapse among healthy women.
Health Psychology, 13, 274-277.
Simons-Morton, D. G., Calfas, K. J., & Oldenburg, B. (1998).
Effects of interventions in health-care settings on physical
activity or cardiorespiratory fitness. American Journal of Preventive Medicine, 16, 19-22.
Stone, E. J., McKenzie, T. L., Welk, G. J., & Booth, M. L. (1998).
Pre-school to college-aged physical activity intervention studies:
Review and synthesis. American Journal of Preventive Medicine, 15, 298-315.
Stone, E. J., Osganian, S. K., McKinlay, S. M., Wu, M. C., Webber,
L. S., Luepker, R. V, Perry, C. L., Parcel, G. S., & Elder, J. P.
(1996). Operational design and quality control in the CATCH
multicenter trial. Preventive Medicine, 25, 384-399.
Tell, G. S., & Vellar, O. D. (1987). Noncommunicable disease risk
factor intervention in Norwegian adolescents: The Oslo Youth
Study. In B. Hetzel & G. Berenson (Eds.), Cardiovascular risk
factors in childhood: Epidemiology and prevention. Amsterdam:
Elsevier Science.
U.S. Department of Health and Human Services. (1996). Physical
activity and health: A report of the surgeon general. Atlanta, GA:
Centers for Disease Control and Prevention, National Center for
Chronic Disease Prevention and Health Promotion.
Williamson, D. F, Kahn, H. S., Remington, P. L., & Anda, R. F.
(1990). The 10-year incidence of overweight and major weight
gain in U.S. adults. Archives of Internal Medicine, 150, 665-672.
Wimbush, E., MacGregor, A., & Fraser, E. (1998). The effects of a
national mass media campaign on walking in Scotland. Health
Promotion International, 13(1), 45-53.
Young, D. R., Haskell, W. L., Taylor, C. B., & Fortmann, S. P.
(1996). Effect of community health education on physical
activity knowledge, attitudes, and behavior. American Journal of
Epidemiology, 144, 264-274.