Reducing the Decline in Physical Activity during Pregnancy: A Systematic Review of Behaviour Change Interventions

Physical activity (PA) typically declines throughout pregnancy. Low levels of PA are associated with excessive weight gain and subsequently increase risk of pre-eclampsia, gestational diabetes mellitus, hypertension disorders, delivery by caesarean section and stillbirth. Systematic reviews on PA during pregnancy have not explored the efficacy of behaviour change techniques or related theory in altering PA behaviour. This systematic review evaluated the content of PA interventions to reduce the decline of PA in pregnant women with a specific emphasis on the behaviour change techniques employed to elicit this change. Search and Review Methodology Literature searches were conducted in eight databases. Strict inclusion and exclusion criteria were employed. Two reviewers independently evaluated each intervention using the behaviour change techniques (BCT) taxonomy to identify the specific behaviour change techniques employed. Two reviewers independently assessed the risk of bias using the guidelines from the Cochrane Collaboration. Overall quality was determined using the GRADE approach.  A total of 1140 potentially eligible papers were identified from which 14 studies were selected for inclusion. Interventions included counselling (n = 6), structured exercise (n = 6) and education (n = 2). Common behaviour change techniques employed in these studies were goal setting and planning, feedback, repetition and substitution, shaping knowledge and comparison of behaviours. Regular face-to-face meetings were also commonly employed. PA change over time in intervention groups ranged from increases of 28% to decreases of 25%. In 8 out of 10 studies, which provided adequate data, participants in the intervention group were more physically active post intervention than controls.  Physical activity interventions incorporating behaviour change techniques help reduce the decline in PA throughout pregnancy. Range of behaviour change techniques can be implemented to reduce this decline including goals and planning, shaping knowledge and comparison of outcomes. A lack of high quality interventions hampers conclusions of intervention effectiveness.

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title: A preliminary study on the pattern of weight change from pregnancy to 6 months postpartum: a latent growth model approach
abstract: There is a lack of comprehensive understanding about patterns of weight change from pregnancy to childbirth and beyond. We describe the trajectory of weight change pattern from pre-pregnancy to 6 months postpartum and examine demographical and perinatal variables that predict the weight change using the latent growth model (LGM).Design and subjects:This study used a longitudinal design. The study participants were 120 women whose body weights were measured at eight time points.The adjusted mean pre-pregnancy weight was 52.57 kg. When the weight growth rate for 10–13 weeks of pregnancy and pre-pregnancy weight was set to 1, the body-weight change rate was 2.20 during the second trimester, 2.14 during the third trimester, –2.90 during the period from the third trimester to 2–3 weeks postpartum, –0.08 during the period from 2–3 weeks to 4–5 weeks postpartum, –0.37 during the period from 4–5 weeks to 11–12 weeks postpartum, and –0.65 during the period from 11–12 weeks to 24–25 weeks postpartum. On average, body weight increased 26.54% (13.95 kg) from pre-pregnancy to 36–39 weeks of pregnancy and body weight remained 6.26% (3.29 kg) higher at 24–25 weeks postpartum compare with pre-pregnancy. In terms of factors related to body weight, age was positively associated with pre-pregnancy body weight. Parity had a negative effect on the change of body weight. Women who had an increased change rate in body weight had higher newborn birth weights.We found that weight change from pregnancy to postpartum followed a pattern that could be specified using the LGM approach. The women retained more than 6% of weight at 6 months postpartum compared with their pre-pregnancy weight.

title: Interpregnancy weight change and risk of adverse pregnancy outcomes: a population-based study
abstract: Maternal obesity has been positively associated with risk of adverse pregnancy outcomes, but evidence of a causal relation is scarce. Causality would be lent support if temporal changes in weight affected risk of adverse pregnancy outcomes.



We examined the associations between change in prepregnancy body-mass index (BMI) from the first to the second pregnancies, and the risk of adverse outcomes during the second pregnancy in a nationwide Swedish study of 151 025 women who had their first two consecutive singleton births between 1992 and 2001.



Compared with women whose BMI changed between -1.0 and 0.9 units, the adjusted odds ratios for adverse pregnancy outcomes for those who gained 3 or more units during an average 2 years were: pre-eclampsia, 1.78 (95% CI 1.52-2.08); gestational hypertension 1.76 (1.39-2.23); gestational diabetes 2.09 (1.68-2.61); caesarean delivery 1.32 (1.22-1.44); stillbirth 1.63 (1.20-2.21); and large-for-gestational-age birth 1.87 (1.72-2.04). The associations were linearly related to the amount of weight change and were also noted in women who had a healthy prepregnancy BMI for both pregnancies.



These findings lend support to a causal relation between being overweight or obese and risks of adverse pregnancy outcomes. Additionally they suggest that modest increases in BMI before pregnancy could result in perinatal complications, even if a woman does not become overweight. Our results provide robust epidemiological evidence for advocating weight loss in overweight and obese women who are planning to become pregnant and, to prevent weight gain before pregnancy in women with healthy BMIs.

title: Weight and pregnancy
abstract: Women who maintain a normal healthy weight, before, during, and after pregnancy have better outcomes

title: Physical activity, exercise, and physical fitness: definitions and distinctions for health-related research.
abstract: "Physical activity," "exercise," and "physical fitness" are terms that describe different concepts. However, they are often confused with one another, and the terms are sometimes used interchangeably. This paper proposes definitions to distinguish them. Physical activity is defined as any bodily movement produced by skeletal muscles that results in energy expenditure. The energy expenditure can be measured in kilocalories. Physical activity in daily life can be categorized into occupational, sports, conditioning, household, or other activities. Exercise is a subset of physical activity that is planned, structured, and repetitive and has as a final or an intermediate objective the improvement or maintenance of physical fitness. Physical fitness is a set of attributes that are either health- or skill-related. The degree to which people have these attributes can be measured with specific tests. These definitions are offered as an interpretational framework for comparing studies that relate physical activity, exercise, and physical fitness to health.

title: Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period
abstract: New guidelines for exercise in pregnancy and postpartum have been published by the American College of Obstetricians and Gynecologists

In January 2002 the American College of Obstetricians and Gynecologists (ACOG) published new recommendations and guidelines for exercise during pregnancy and the postpartum period.1 Regular exercise is promoted for its overall health benefits. Pregnancy is recognised as a unique time for behaviour modification and is no longer considered a condition for confinement. It is currently recognised that habits adopted during pregnancy could affect a woman's health for the rest of her life. For the first time the recommendation suggests a possible role for exercise in the prevention and management of gestational diabetes.

The recommendations also promote exercise for sedentary women and those with medical or obstetric complications, but only after medical evaluation and clearance.

Box 1 lists the absolute contraindications to aerobic exercise during pregnancy, and box 2 the relative contraindications. As with any form of exercise prescription, these recommendations also include the warning signs to terminate exercise while pregnant (box 3). The recommendations also offer guidelines for sports and recreational activities. It cautions against participation in contact sports and recommends avoidance of scuba diving.

As for postpartum resumption of activities, the recommendations note that rapid resumption has no adverse effects, but gradual return to former activities is advised. This review includes background and comments to the above recommendations.

The health benefits of physical activity are well recognised, and conversely sedentary habits and low levels of cardiorespiratory fitness are leading risk factors for subsequent development of cardiovascular disease.2,3

The Centers for Disease Control and Prevention and the American College of Sports Medicine (CDC-ACSM) have recommended the accumulation of 30 minutes or more of moderate intensity physical activity on most, and preferably all, days of the  Moderate …

title: Exercise in obese pregnant women: The role of social factors, lifestyle and pregnancy symptoms
abstract: BackgroundPhysical activity may reduce the risk of adverse maternal outcomes, yet there are very few studies that have examined the correlates of exercise amongst obese women during pregnancy. We examined which relevant sociodemographic, obstetric, and health behaviour variables and pregnancy symptoms were associated with exercise in a small sample of obese pregnant women.MethodsThis was a secondary analysis using data from an exercise intervention for the prevention of gestational diabetes in obese pregnant women. Using the Pregnancy Physical Activity Questionnaire (PPAQ), 50 obese pregnant women were classified as "Exercisers" if they achieved ≥900 kcal/wk of exercise and "Non-Exercisers" if they did not meet this criterion. Analyses examined which relevant variables were associated with exercise status at 12, 20, 28 and 36 weeks gestation.ResultsObese pregnant women with a history of miscarriage; who had children living at home; who had a lower pre-pregnancy weight; reported no nausea and vomiting; and who had no lower back pain, were those women who were most likely to have exercised in early pregnancy. Exercise in late pregnancy was most common among tertiary educated women.ConclusionsOffering greater support to women from disadvantaged backgrounds and closely monitoring women who report persistent nausea and vomiting or lower back pain in early pregnancy may be important. The findings may be particularly useful for other interventions aimed at reducing or controlling weight gain in obese pregnant women.

title: Morphometric and neurodevelopmental outcome at age five years of the offspring of women who continued to exercise regularly throughout pregnancy.
abstract: To test the hypothesis that continuing regular, vigorous, sustained exercise throughout pregnancy adversely affects morphometric and neurodevelopmental outcome in offspring at 5 years of age.



The offspring of 20 women who exercised were compared with those of 20 physically active control subjects. The women and their offspring were matched for multiple prenatal and postnatal variables known to influence outcome. All women were enrolled before the index pregnancy, monitored throughout, and had clinically normal antenatal, intrapartum, and postnatal courses. Morphometric measures were obtained at birth and at 5 years of age by a single, trained observer. Neurodevelopment was assessed by developmental psychologists masked to maternal exercise status. Data were analyzed with an unpaired Student t test.



At birth, head circumference and length were similar, but the offspring of the exercising women weighed less (3.40 +/- 0.80 vs 3.64 +/- 0.70 kg) and had less fat (10.5% +/- 0.9% vs 15.1% +/- 0.6%). At 5 years of age, head circumference and height were similar, but the offspring of the women who exercised weighed less (18.0 +/- 0.5 vs 19.5 +/- 0.6 kg) and had a lower sum (sigma) of five site skinfolds (37 +/- 1 vs 44 +/- 2 mm). Motor, integrative, and academic readiness skills were similar. However, the exercise offspring performed significantly better on the Wechsler scales (125 +/- 2 vs 116 +/- 3) and tests of oral language skills (119 +/- 2 vs 109 +/- 3).



These data refute the hypothesis and suggest that exercise during pregnancy reduces the subcutaneous fat mass of the offspring.

title: Early life determinants of physical activity in 11 to 12 year olds: cohort study
abstract: To examine factors in early life (up to age 5 years) that are associated with objectively measured physical activity in 11-12 year olds.  Avon longitudinal study of parents and children, United Kingdom.  Children aged 11-12 years from the Avon longitudinal study of parents and children.  Physical activity levels in counts per minute (cpm) and minutes of moderate to vigorous physical activity for seven days measured with a uniaxial actigraph accelerometer.  Valid actigraph data, defined as at least three days of physical activity for at least 10 hours a day, were collected from 5451 children. Several factors were associated with physical activity at ages 11-12 years. Regression coefficients are compared with the baseline of “none” for categorical variables: maternal brisk walking during pregnancy (regression coefficient 5.0, 95% confidence interval −8.5 to 18.5; cpm for <1 h/wk and ≥2 h/wk of physical activity 17.7, 5.3 to 30.1), maternal swimming during pregnancy (21.5, 10.9 to 32.1 and cpm for <1 h/wk and ≥2 h/wk of physical activity 24.2, 7.8 to 40.7), parents’ physical activity when the child was aged 21 months (28.5, 15.2 to 41.8 and cpm of physical activity for either parent active and both parents active 33.5, 17.8 to 49.3), and parity assessed during pregnancy (2.9, −7.6 to 13.4 and cpm of physical activity for 1 and ≥2 parity 21.2, 7.1 to 35.3).  Few factors in early life predicted later physical activity in 11-12 year olds. Parents’ physical activity during pregnancy and early in the child’s life showed a modest association with physical activity of the child at age 11-12 years, suggesting that active parents tend to raise active children. Helping parents to increase their physical activity therefore may promote children’s activity.

title: Pregnancy: a "teachable moment" for weight control and obesity prevention.
abstract: Excessive gestational weight gain has been shown to relate to high-postpartum weight retention and the development of overweight and obesity later in life. Because many women are concerned about the health of their babies during pregnancy and are in frequent contact with their healthcare providers, pregnancy may be an especially powerful "teachable moment" for the promotion of healthy eating and physical activity behaviors among women. Initial research suggests that helping women gain the recommended amount during pregnancy through healthy eating and physical activity could make a major contribution to the prevention of postpartum weight retention. However, more randomized controlled trials with larger sample sizes are needed to identify the most effective and disseminable intervention. Providers have the potential to prevent high postpartum weight retention and future obesity by monitoring weight gain during pregnancy and giving appropriate advice about recommended amounts of gestational weight gain.

title: Understanding the potential of teachable moments: the case of smoking cessation.
abstract: The label 'teachable moment' (TM) has been used to describe naturally occurring health events thought to motivate individuals to spontaneously adopt risk-reducing health behaviors. This manuscript summarizes the evidence of TMs for smoking cessation, and makes recommendations for conceptual and methodological refinements to improve the next generation of related research. TM studies were identified for the following event categories: office visits, notification of abnormal test results, pregnancy, hospitalization and disease diagnosis. Cessation rates associated with pregnancy, hospitalization and disease diagnosis were high (10-60 and 15-78%, respectively), whereas rates for clinic visits and abnormal test results were consistently lower (2-10 and 7-21%, respectively). Drawing from accepted conceptual models, a TM heuristic is outlined that suggests three domains underlie whether a cueing event is significant enough to be a TM for smoking cessation: the extent to which the event (1) increases perceptions of personal risk and outcome expectancies, (2) prompts strong affective or emotional responses, and (3) redefines self-concept or social role. Research in TMs could be improved by giving greater attention to assessment of conceptually grounded cognitive and emotional variables, appropriately timed assessment and intervention, and inclusion of appropriate target and comparison samples.

title: Physical activity patterns during pregnancy.
abstract: The aim of the study was to describe the mode, frequency, duration, and intensity of physical activity among pregnant women, to explore whether these women reached the recommended levels of activity, and to explore how these patterns changed during pregnancy.



This study, as part of the third phase of the Pregnancy, Infection, and Nutrition Study, investigated physical activity among 1482 pregnant women. A recall of the different modes, frequency, duration, and intensity of physical activity during the past week was assessed in two telephone interviews at 17-22 and 27-30 wk of gestation.



Most women reported some type of physical activity during both periods. Child and adult care giving, indoor household, and recreational activities constituted the largest proportion of total reported activity. The overall physical activity level decreased during pregnancy, particularly in care giving, outdoor household, and recreational activity. Women who were active during the second and the third trimesters reported higher levels of activity in all modes of activity than those who became active or inactive during pregnancy. The majority did not reach the recommended level of physical activity.



These data suggest that self-reported physical activity decreased from the second to the third trimesters, and only a small proportion reached the recommended level of activity during pregnancy. Further research is needed to explore if physical activity rebounds during the postpartum period.

title: Leisure-time physical activity among pregnant women in the US.
abstract: Few population-based data exist that describe leisure-time physical activity among pregnant women. The purpose of this study was to characterise the prevalence of leisure activity and to examine characteristics associated with participation in leisure activity during pregnancy. Using data collected from the year 2000 Behavioral Risk Factor Surveillance System, information on leisure activity was collected during telephone interviews from 1979 pregnant women and 44,657 non-pregnant women 18-44 years of age, representative of the US population. The prevalence of any leisure activity in the past month was 65.6%, 95% confidence interval [95% CI] 62.0, 69.1, among pregnant women and 73.1% [95% CI 72.4, 73.9] among non-pregnant women. The prevalence of recommended activity was also lower among pregnant women than non-pregnant women (15.8% vs. 26.1%). The most common leisure activity for pregnant women was walking, followed by activities such as swimming laps, weight lifting, gardening, and aerobics. Among pregnant women, any leisure activity was significantly higher for those with higher education, younger age, and excellent or very good health than for those with fair or poor health. Pregnant women reported less leisure activity than non-pregnant women of the same age. Studies to understand the enablers and barriers to participating in leisure activity during pregnancy are needed.

title: Prevalence and correlates of objectively measured physical activity and sedentary behavior among US pregnant women.
abstract: Physical activity is recommended for pregnant women without medical or obstetric complications. This study described the prevalence and correlates of objectively-measured physical activity and sedentary behavior among United States pregnant women.



Using cross-sectional data collected from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES), 359 pregnant women ≥16 years wore an accelerometer for 1 week.



Women participated in a mean of 12.0 minutes/day (standard error (SE) 0.86) of moderate activity and 0.3 minutes/day (SE 0.08) of vigorous activity. Mean moderate to vigorous physical activity varied by trimester: 11.5 minutes/day in first trimester, 14.3 minutes/day in second trimester, and 7.6 minutes/day in third trimester. On average, women spent 57.1% of their monitored time in sedentary behaviors. In multivariable adjusted models, moderate to vigorous physical activity was higher in the first (p=0.02) and second (p<0.001) trimesters compared to the third trimester, and among women with higher household income (p=0.03) compared to lower household income. In multivariable adjusted models, average counts/minute was higher in the second compared to the third trimester (p=0.04).



Most pregnant women spent more than half of the monitored day in sedentary behaviors and did not meet recommendations for physical activity.

title: Prospective examination of pregnant and nonpregnant women’s physical activity beliefs and behaviours
abstract: The purpose was to prospectively assess if the theory of planned behaviour guided physical activity (PA) beliefs and behaviours for pregnant compared to nonpregnant women.  Theoretically based prospective studies can advance our understanding and promotion of PA during each trimester of pregnancy.  Participants (N = 81) completed self-report assessments of their PA beliefs and behaviours at Time 1 (first trimester/baseline), Time 2 (second trimester/3 months), and Time 3 (third trimester/6 months).  The elicited PA beliefs and behaviours varied by assessment time and group. For the PA beliefs, the nonpregnant women’s (n = 43) salient beliefs were consistent across time. For the pregnant women (n = 38) the beliefs varied across time, with pregnant-specific beliefs that differed by trimester. For example, nausea was a common PA disadvantage reported in the first trimester, compared to increased weight/size in the third trimester; whereas the nonpregnant women reported time as the main disadvantage across all three assessments. For PA behaviour, the nonpregnant women reported more moderate PA than the pregnant women across all three assessments; with the pregnant women’s moderate PA decreasing from the first, to the second, to the third trimester.  Trimester-specific PA interventions are encouraged to increase and maintain PA during pregnancy.

title: Treatment and prevention of obesity--are there critical periods for intervention?
abstract: Both professionals and the public view obesity, increasingly apparent in childhood, and already highly prevalent in adults in the Western world, as one of, if not, the most important public health problem of our times. The considerable effort expended on researching risk factors for obesity (a Medline search for studies examining risk factors for obesity conducted at the time of writing this editorial (November 2005) resulted in 264 326 hits) contrasts starkly with the simplicity of the key underlying problem, that obesity is largely a consequence of over-nutrition and under-activity. Despite the clarity of this message, there is little evidence-based guidance on successful, viable long-term strategies to prevent or treat obesity.We believe there is a need to develop findings from epidemiological research into coherent decisions regarding prevention and treatment interventions and ultimately appropriate polices for the improvement of public health. Our intention was that a themed issue on obesity in the International Journal of Epidemiology would contribute towards this aim. In the first half of this editorial we review the current evidence for the treatment of adult obesity and conclude that to date there is no strong evidence that such treatments have long-term benefits in terms of health gain. Clearly, lack of evidence does not equate to lack of effect and there is no doubt that most trials to date have not been large enough or had sufficiently long-term follow-up to answer these questions. On the other hand treating established obesity in adulthood may be ‘shutting the gate after the horse has bolted’. Further, epidemiology tells us that obesity is socially patterned, varies between countries, but in recent years has shown marked increases in all countries, and that what we eat and the exercise we take is largely determined by the food industry, transport policy, and the built environment (see for example the piece by Cummins and Macintyre in this issue 1 ). Thus, a population approach to the primary prevention of obesity and to the prevention of its associated diseases is more likely to be beneficial than an individual or small group level approach such as treating established obesity. Animal studies suggest that brief interventions during critical or sensitive periods of development can have lasting effects in terms of disease prevention. This seems such an exciting prospect to us that we spend the second half of this editorial considering whether there is sufficient evidence relating critical/sensitive periods of development to the risk of later obesity and its associated diseases to warrant trials in humans of such interventions.

title: Antenatal exercise to improve outcomes in overweight or obese women: A systematic review
abstract: Women who are overweight or obese during pregnancy are at increased risk of a number of adverse pregnancy outcomes.  To review the literature systematically to assess the benefits and harms of an exercise intervention for pregnant women who are overweight or obese. Search strategy. A literature search of PUBMED, SCOPUS, the Cochrane Controlled Trials Register (CENTRAL) and the Australian and International Clinical Trials Registers was performed, as well as an additional hand search through bibliographies of various publications. There were no date or language restrictions. Selection criteria. Studies included were randomized controlled trials comparing supervised antenatal exercise intervention with routine standard antenatal care in women who were overweight or obese during pregnancy. The primary outcome was maternal gestational weight gain. The quality of each study was assessed utilizing standard Cochrane systematic review methodology.  Six randomized controlled trials and one quasi‐randomized trial were identified and included, involving a total of 276 women who were overweight or obese during pregnancy.  Provision of a supervised antenatal exercise intervention was associated with lower gestational weight gain (five trials, 216 participants, mean difference of −0.36 kg, 95% confidence interval −0.64 to −0.09 kg) when compared with standard antenatal care.  A monitored physical activity intervention appears to be successful in limiting gestational weight gain; however, the effect on maternal and infant health is less certain.

title: Changing diet and physical activity to reduce gestational weight gain: a meta‐analysis
abstract: Excessive pregnancy weight gain is associated with adverse maternal and child health outcomes. Intervention developers have assumed that adopting a healthier diet and increasing physical activity in pregnancy can limit weight gain, but evaluations of such interventions have yielded mixed results. Recent reviews of this literature have not identified defining characteristics of effective interventions. We systematically reviewed 10 published controlled trials of interventions that aimed to reduce gestational weight gain through changes in diet or physical activity. Characteristics of the sample, intervention content and delivery, and methodology were categorized. Meta‐analysis showed that, overall, diet and physical activity change was effective in reducing gestational weight gain, but there was considerable heterogeneity in outcomes. Our analysis points to sample characteristics and aspects of intervention design, content, delivery and evaluation which differ between studies and may explain variation in effectiveness. Failure to evaluate changes in behaviour or its psychological determinants, and under‐reporting of intervention content, may obscure identification of the processes by which weight change is effected. This limits our ability to discern active intervention ingredients. We suggest that behaviour‐based gestational weight gain reduction interventions be more systematically designed, evaluated and reported to build on insights from behavioural science.

title: Interventions during pregnancy to reduce excessive gestational weight gain: a systematic review assessing current clinical evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system
abstract: Please cite this paper as: Ronnberg A, Nilsson K. Interventions during pregnancy to reduce excessive gestational weight gain: a systematic review assessing current clinical evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. BJOG 2010;117:1327–1334.

title: From Theory to Intervention: Mapping Theoretically Derived Behavioural Determinants to Behaviour Change Techniques
abstract: Theory provides a helpful basis for designing interventions to change behaviour but offers little guidance on how to do this. This paper aims to illustrate methods for developing an extensive list of behaviour change techniques (with definitions) and for linking techniques to theoretical constructs. A list of techniques and definitions was generated from techniques published in two systematic reviews, supplemented by “brainstorming” and a systematic search of nine textbooks used in training applied psychologists. Inter-rater reliability of extracting the techniques and definitions from the textbooks was assessed. Four experts judged which techniques would be effective in changing 11 theoretical constructs associated with behaviour change. 
Thirty-five techniques identified in the reviews were extended to 53 by brainstorming and to 137 by consulting textbooks. Agreement for the 53 definitions was 74.7 per cent (15.4% cells completed and 59.3% cells empty for both raters). Agreement about the link between the 35 techniques and theoretical constructs was 71.7 per cent of 385 judgments (12.2% agreement that effective and 59.5% agreement that not effective). This preliminary work demonstrates the possibility of developing a comprehensive, reliable taxonomy of techniques linked to theory. Further refinement is needed to eliminate redundancies, resolve uncertainties, and complete technique definitions.

title: Developing and evaluating complex interventions: the new Medical Research Council guidance
abstract: Evaluating complex interventions is complicated. The Medical Research Council's evaluation framework (2000) brought welcome clarity to the task. Now the council has updated its guidance

title: Theory, evidence and Intervention Mapping to improve behavior nutrition and physical activity interventions
abstract: BackgroundThe present paper intends to contribute to the debate on the usefulness and barriers in applying theories in diet and physical activity behavior-change interventions.DiscussionSince behavior theory is a reflection of the compiled evidence of behavior research, theory is the only foothold we have for the development of behavioral nutrition and physical activity interventions. Application of theory should improve the effectiveness of interventions. However, some of the theories we use lack a strong empirical foundation, and the available theories are not always used in the most effective way. Furthermore, many of the commonly-used theories provide at best information on what needs to be changed to promote healthy behavior, but not on how changes can be induced. Finally, many theories explain behavioral intentions or motivation rather well, but are less well-suited to explaining or predicting actual behavior or behavior change.For more effective interventions, behavior change theory needs to be further developed in stronger research designs and such change-theory should especially focus on how to promote action rather than mere motivation. Since voluntary behavior change requires motivation, ability as well as the opportunity to change, further development of behavior change theory should incorporate environmental change strategies. Mapping may help to further improve the application of theories in nutrition and physical activity behavior change.

title: Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement
abstract: David Moher and colleagues introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses

title: ACSM's Guidelines for Exercise Testing and Prescription
abstract: Clinical Exercise Testing 6 Interpretation of Clinical Exercise Test  General Principles of Exercise Prescription 8 Exercise Prescription for Healthy Populations With Special Considerations and Environmental Considerations 9 Exercise Prescription For Patients With Cardiovascular and Cerebrovascular Disease 10 Exercise Prescription for Populations With Other Chronic Diseases and Health Conditions 11 Behavioral Theories and Strategies for Promoting Exercise SECTION IV: APPENDICES Appendix A Common Medications Appendix B Medical Emergency Management

title: Compendium of physical activities: an update of activity codes and MET intensities.
abstract: We provide an updated version of the Compendium of Physical Activities, a coding scheme that classifies specific physical activity (PA) by rate of energy expenditure. It was developed to enhance the comparability of results across studies using self-reports of PA. The Compendium coding scheme links a five-digit code that describes physical activities by major headings (e.g., occupation, transportation, etc.) and specific activities within each major heading with its intensity, defined as the ratio of work metabolic rate to a standard resting metabolic rate (MET). Energy expenditure in MET-minutes, MET-hours, kcal, or kcal per kilogram body weight can be estimated for specific activities by type or MET intensity. Additions to the Compendium were obtained from studies describing daily PA patterns of adults and studies measuring the energy cost of specific physical activities in field settings. The updated version includes two new major headings of volunteer and religious activities, extends the number of specific activities from 477 to 605, and provides updated MET intensity levels for selected activities.

title: The Behavior Change Technique Taxonomy (v1) of 93 Hierarchically Clustered Techniques: Building an International Consensus for the Reporting of Behavior Change Interventions
abstract: BackgroundCONSORT guidelines call for precise reporting of behavior change interventions: we need rigorous methods of characterizing active content of interventions with precision and specificity.ObjectivesThe objective of this study is to develop an extensive, consensually agreed hierarchically structured taxonomy of techniques [behavior change techniques (BCTs)] used in behavior change interventions.MethodsIn a Delphi-type exercise, 14 experts rated labels and definitions of 124 BCTs from six published classification systems. Another 18 experts grouped BCTs according to similarity of active ingredients in an open-sort task. Inter-rater agreement amongst six researchers coding 85 intervention descriptions by BCTs was assessed.ResultsThis resulted in 93 BCTs clustered into 16 groups. Of the 26 BCTs occurring at least five times, 23 had adjusted kappas of 0.60 or above.Conclusions“BCT taxonomy v1,” an extensive taxonomy of 93 consensually agreed, distinct BCTs, offers a step change as a method for specifying interventions, but we anticipate further development and evaluation based on international, interdisciplinary consensus.

title: Strengthening evaluation and implementation by specifying components of behaviour change interventions: a study protocol
abstract: BackgroundThe importance of behaviour change in improving health is illustrated by the increasing investment by funding bodies in the development and evaluation of complex interventions to change population, patient, and practitioner behaviours. The development of effective interventions is hampered by the absence of a nomenclature to specify and report their content. This limits the possibility of replicating effective interventions, synthesising evidence, and understanding the causal mechanisms underlying behaviour change. In contrast, biomedical interventions are precisely specified (e.g., the pharmacological 'ingredients' of prescribed drugs, their dose and frequency of administration). For most complex interventions, the precise 'ingredients' are unknown; descriptions (e.g., 'behavioural counseling') can mean different things to different researchers or implementers. The lack of a method for specifying complex interventions undermines the precision of evidence syntheses of effectiveness, posing a problem for secondary, as well as primary, research.We aim to develop a reliable method of specifying intervention components ('techniques') aimed at changing behaviour.DesignThe research will be conducted in three phases. The first phase will develop the nomenclature. We will refine a preliminary list of techniques and definitions. Using a formal consensus method, experts will then define the key attributes of each technique and how it relates to, and differs from, others. They will evaluate the techniques and their definitions until they achieve an agreed-upon list of clearly defined, nonredundant techniques. The second phase will test the nomenclature. Trained experts (primary researchers and systematic reviewers), equipped with a coding manual and guidance, will use the nomenclature to code published descriptions of complex interventions. Reliability between experts, over time, and across types of users will be assessed. We will assess whether using the nomenclature to write intervention descriptions enhances the clarity and replicability of interventions. The third phase will develop a web-based users' resource of clearly specified and nonredundant techniques, which will aid the scientific understanding of, and development of, effective complex interventions. Dissemination throughout the project will be through stakeholder meetings, targeted multidisciplinary workshops, conference presentation, journal publication, and publication in an interactive web-based platform (a Wiki).DiscussionThe development of a reliable method of specifying intervention components aimed at changing behaviour will strengthen the scientific basis for developing, evaluating, and reporting complex interventions. It will improve the precision of evidence syntheses of effectiveness, thus enhancing secondary, as well as primary, research.

title: Grading quality of evidence and strength of recommendations
abstract: Users of clinical practice guidelines and other recommendations need to know how much confidence they can place in the recommendations. Systematic and explicit methods of making judgments can reduce errors and improve communication. We have developed a system for grading the quality of evidence and the strength of recommendations that can be applied across a wide range of interventions and contexts. In this article we present a summary of our approach from the perspective of a guideline user. Judgments about the strength of a recommendation require consideration of the balance between benefits and harms, the quality of the evidence, translation of the evidence into specific circumstances, and the certainty of the baseline risk. It is also important to consider costs (resource utilisation) before making a recommendation. Inconsistencies among systems for grading the quality of evidence and the strength of recommendations reduce their potential to facilitate critical appraisal and improve communication of these judgments. Our system for guiding these complex judgments balances the need for simplicity with the need for full and transparent consideration of all important issues. Clinical guidelines are only as good as the evidence and judgments they are based on. The GRADE approach aims to make it easier for users to assess the judgments behind recommendations

title: Maternal-fetal disease information as a source of exercise motivation during pregnancy.
abstract: A Protection Motivation Theory (PMT) framework was used to examine whether information about the role of exercise in preventing maternal-fetal disease served as a meaningful source of exercise motivation.



Pregnant women (n = 208) were randomly assigned into one of three conditions: PMT, attention control, and noncontact control. Women in the PMT group read a brochure about the benefits of exercise during pregnancy incorporating the major components of PMT; perceived vulnerability (PV), perceived severity (PS), response efficacy (RE), and self-efficacy (SE). Participants in the attention-control condition read a brochure about diet. Following treatment, all participants completed measures of their beliefs toward maternal-fetal disease and exercise, goal intention (GI), and implementation intention (IMI). One week later, a measure of self-reported exercise behavior was collected.



Main outcome measures were PMT variables (PV, PS, RE, and SE), GI, IMI, and follow-up physical activity.



Participants assigned to the PMT-present group reported significantly higher PS, RE, SE, GI, and increased exercise behavior. PS, RE, and SE predicted GI, GI predicted IMI, and IMI predicted exercise behavior.



Information grounded in PMT is effective in influencing pregnant women's beliefs and intentions as well as changing their initial behavior.

title: Adherence to walking or stretching, and risk of preeclampsia in sedentary pregnant women.
abstract: Pregnant women at risk for preeclampsia may benefit from the positive effects of exercise, but they may be unlikely to adhere to an exercise program. A randomized trial was conducted with 124 sedentary pregnant women to compare the effects of walking exercise to a stretching exercise on adherence and on the preeclampsia risk factors of heart rate (HR), blood pressure, and weight gain. Walkers exercised less than stretchers both overall and as pregnancy advanced. HR and blood pressure were lower among stretchers than walkers, but weight gain did not differ between the groups. For sedentary pregnant women, a stretching exercise may be more effective than walking in mitigating the risk of preeclampsia due to higher adherence and possible cardiac-physiologic effects.

title: Feasibility and efficacy of a physical activity intervention among pregnant women: the behaviors affecting baby and you (B.A.B.Y.) study.
abstract: Physical activity during pregnancy is associated with reduced risk of adverse maternal and fetal outcomes. However, the majority of pregnant women are inactive and interventions designed to increase exercise during pregnancy are sparse. We evaluated the feasibility and preliminary efficacy of an exercise intervention among a diverse sample of pregnant women.



The B.A.B.Y. (Behaviors Affecting Baby and You) Study is conducted at a large tertiary care facility in Western Massachusetts. We randomized 110 prenatal care patients (60% Hispanic) to an individually tailored 12-week exercise intervention arm (n = 58) or to a health and wellness control arm (n = 52) at mean = 11.9 weeks gestation. Physical activity was assessed via the Pregnancy Physical Activity Questionnaire (PPAQ).



After the 12-week intervention, the exercise arm experienced a smaller decrease (-1.0 MET-hrs/wk) in total activity vs. the control arm (-10.0 MET-hrs/wk; P = .03), and a higher increase in sports/exercise (0.9 MET-hrs/wk) vs. the control arm (-0.01 MET-hrs/wk; P = .02). Intervention participants (95%) reported being satisfied with the amount of information received and 86% reported finding the study materials interesting and useful.



Findings support the feasibility and preliminary efficacy of a tailored exercise intervention in increasing exercise in a diverse sample of pregnant women.

title: Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial.
abstract: Maternal obesity and excessive gestational weight gain (GWG) are major short- and long-term risk factors for maternal and fetal complications.



The objective was to study whether a lifestyle intervention based on a brochure or on active education can improve dietary habits, increase physical activity (PA), and reduce GWG in obese pregnant women.



In this randomized controlled trial, 195 white, obese pregnant women [age: 29 + or - 4 y; body mass index (in kg/m(2)); 33.6 + or - 4.2] were randomly assigned into 3 groups: a group that received nutritional advice from a brochure, a group that received the brochure and lifestyle education by a nutritionist, and a control group. Nutritional habits were evaluated every trimester through 7-d food records. PA was evaluated with the Baecke questionnaire.



Energy intake did not change during pregnancy and was comparable in all groups. Fat intake, specifically saturated fat intake, decreased and protein intake increased from the first to the third trimester in the passive and active groups compared with an opposite change in the control group. Calcium intake and vegetable consumption increased during pregnancy in all groups. PA decreased in all groups, especially in the third trimester. No significant differences in GWG and obstetrical or neonatal outcome could be observed between the groups.



Both lifestyle interventions improved the nutritional habits of obese women during pregnancy. Neither PA nor GWG was affected.

title: Community-based Exercise and Dietary Intervention During Pregnancy:A Pilot Study
abstract: To determine the feasibility of implementing a communitybased exercise/dietary intervention program targeted at socioeconomically deprived pregnant women living in an urban core in an attempt to reduce risks of obesity and diabetes.  Fifty-two participants were enrolled and randomized into additional intervention (AI) and standard care (SC) groups. Participants in the AI group undertook group and homebased exercises during pregnancy and received computerassisted Food Choice Map dietary interviews and counselling. Participants in the SC group received an information package on diet and activity for a healthy pregnancy.  Forty-five participants completed the study (SC group, n=21, AI group, n=24). No adverse effects of exercise were observed during the study. Physical activity levels in the AI group were greater than those in the SC group (p  The results of this pilot study demonstrated the feasibility of the lifestyle intervention during pregnancy and its potential to improve pregnancy outcomes in urban communities.

title: A diet and physical activity intervention for preventing weight retention among Taiwanese childbearing women: a randomised controlled trial.
abstract: to examine the effect of individual counselling on diet and physical activity from pregnancy to six months post partum, or from birth to six months post partum, on weight retention among Taiwanese women.



a randomised controlled trial assigned participants to two experimental groups [from pregnancy to six months post partum (EP) and from birth to six months post partum (EPP)] and one comparison group.



a 3900-bed medical centre in northern Taiwan with around 3000 births annually.



a sample of 189 women who had regular check-ups during pregnancy and gave birth at the medical centre.



the comparison group received the routine outpatient department obstetric educational programme. The EP group attended regularly scheduled clinic visits with individualised dietary and physical activity education plans from 16 gestational weeks to six months post partum, and received on brochure. The EPP group received the same educational intervention as the EP group from 24-48 hours after birth to six months post partum.



body weight, body mass index, health-promoting behaviour and psycho-social variables (self-efficacy, body image, depression and social support).



average gestational weight gain was 14.02, 15.27 and 16.22 kg in the three EP, EPP and comparison groups respectively, and average weight retention at six months post partum was 2.34, 4.06 and 5.08 kg in the three groups, respectively.



a diet and physical activity intervention from pregnancy is effective for reducing post-pregnancy weight retention.



the findings of the present study should be taken into consideration when incorporating significant others and weight-loss maintenance strategies with interventions for a healthier family lifestyle.

title: Improving diet and exercise in pregnancy with Video Doctor counseling: a randomized trial.
abstract: To determine if an interactive, computerized Video Doctor counseling tool improves self-reported diet and exercise in pregnant women.



A randomized trial comparing a Video Doctor intervention to usual care in ethnically diverse, low-income, English-speaking pregnant women was conducted. Brief messages about diet, exercise, and weight gain were delivered by an actor-portrayed Video Doctor twice during pregnancy.



In the Video Doctor group (n=158), there were statistically significant increases from baseline in exercise (+28 min), intake of fruits and vegetables, whole grains, fish, avocado and nuts, and significant decreases in intake of sugary foods, refined grains, high fat meats, fried foods, solid fats, and fast food. In contrast, there were no changes from baseline for any of these outcomes in the usual care group (n=163). Nutrition knowledge improved significantly over time in both groups but more so in the Video Doctor group. Clinician-patient discussions about these topics occurred significantly more frequently in the Video Doctor group. There was no difference in weight gain between groups.



A brief Video Doctor intervention can improve exercise and dietary behaviors in pregnant women.



The Video Doctor can be integrated into prenatal care to assist clinicians with effective diet and exercise counseling.

title: Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial
abstract: In a cluster-randomized trial, Riitta Luoto and colleagues find that counseling on diet and activity can reduce the birthweight of babies born to women at risk of developing gestational diabetes mellitus (GDM), but fail to find an effect on GDM.

title: Randomized controlled trial to prevent excessive weight gain in pregnant women
abstract: The Institute of Medicine (IOM) recommends that normal‐weight women (BMI (body mass index) of 19.8–26.0) gain 25–35 lb (11.4–15.9 kg) during pregnancy, and that overweight women (BMI of 26.1–29.0) gain 15–25 lbs (6.8–11.4 kg). A significant number of normal‐weight women and an even greater proportion of overweight women exceed these guidelines, which increases postpartum weight retention and may contribute to the development of obesity. To determine whether a stepped care, behavioral intervention will decrease the percentage of women who gain more than the IOM recommendation. Randomized controlled trial comparing a stepped-care behavioral intervention with usual care. Women (n=120) who had a BMI>19.8, age>18 and <20 weeks gestation were recruited from a hospital-based clinic serving low-income women and randomized by race and BMI category to the intervention or control group. The intervention group received education about weight gain, healthy eating, and exercise and individual graphs of their weight gain. Those exceeding weight gain goals were given more intensive intervention. Women were followed through pregnancy to their first postpartum clinic visit. The main outcome measure was weight gain during pregnancy categorized as above the IOM recommendations vs below or within the IOM recommendations. The intervention significantly decreased the percentage of normal-weight women who exceeded the IOM recommendations (33 vs 58%, P<0.05). There was a non-significant (P=0.09) effect in the opposite direction among overweight women (59% of intervention and 32% of control gained more than recommended). Postpartum weight retention was strongly related to weight gain during pregnancy (r=0.89).CONCLUSIONS: The intervention reduced excessive weight gain during pregnancy among normal weight women.

title: Protection motivation and self-efficacy: A revised theory of fear appeals and attitude change
abstract: The effects of fear appeals on persuasion were investigated in a factorial experiment that was designed to test a combined model of protection motivation theory and self-efficacy theory. As predicted, the probability of a threat's occurrence and the effectiveness of a coping response both had positive main effects on intentions to adopt a recommended preventive health behavior. More importantly, the findings provided support for self-efficacy expectancy as a fourth component of protection motivation theory: Self-efficacy had a direct influence on intentions and interacted with two other variables of protection motivation theory. The interaction effect was interpreted in terms of two new decision-making strategies that people use when confronted with a fear appeal: a precaution strategy and a hyperdefensiveness strategy. In addition, the results replicated previous findings on the relationship between self-efficacy expectancy and outcome expectancy. A model incorporating protection motivation theory and self-efficacy theory is presented as a possible general model of attitude change.

title: Social Foundations of Thought and Action: A Social Cognitive Theory
abstract: 1. Models of Human Nature and Casualty. 2. Observational Learning. 3. Enactive Learning. 4. Social Diffusion and Innovation. 5. Predictive Knowledge and Forethought. 6. Incentive Motivators. 7. Vicarious Motivators. 8. Self-Regulatory Mechanisms. 9. Self-Efficacy. 10. Cognitive Regulators.

title: Social cognition models and health behaviour: A structured review
abstract: A number of social cognition models have been developed to account for socio-demographic variations in health behaviour. This paper distinguishes between: (a) motivational, (b) behavioural enaction, and (c) multi-stage models of health behaviour. The models are evaluated in terms of advancement of existing knowledge and - where appropriate - predictive utility. Common themes that appear within- and between- these categories are discussed, with consideration of ways in which theory may be advanced by future research. Each approach has associated strengths and weaknesses, suggesting that a “consensus” approach to the study of health behaviour may prove fruitful. Identification of the key constructs across different model types would allow coherent integration and promote further understanding of the psycho-social determinants of health behaviour.

title: The development of a theory-based intervention to promote appropriate disclosure of a diagnosis of dementia
abstract: BackgroundThe development and description of interventions to change professional practice are often limited by the lack of an explicit theoretical and empirical basis. We set out to develop an intervention to promote appropriate disclosure of a diagnosis of dementia based on theoretical and empirical work.MethodsWe identified three key disclosure behaviours: finding out what the patient already knows or suspects about their diagnosis; using the actual words 'dementia' or 'Alzheimer's disease' when talking to the patient; and exploring what the diagnosis means to the patient. We conducted a questionnaire survey of older peoples' mental health teams (MHTs) based upon theoretical constructs from the Theory of Planned Behaviour (TPB) and Social Cognitive Theory (SCT) and used the findings to identify factors that predicted mental health professionals' intentions to perform each behaviour. We selected behaviour change techniques likely to alter these factors.ResultsThe change techniques selected were: persuasive communication to target subjective norm; behavioural modelling and graded tasks to target self-efficacy; persuasive communication to target attitude towards the use of explicit terminology when talking to the patient; and behavioural modelling by MHTs to target perceived behavioural control for finding out what the patient already knows or suspects and exploring what the diagnosis means to the patient. We operationalised these behaviour change techniques using an interactive 'pen and paper' intervention designed to increase intentions to perform the three target behaviours.ConclusionIt is feasible to develop an intervention to change professional behaviour based upon theoretical models, empirical data and evidence based behaviour change techniques. The next step is to evaluate the effect of such an intervention on behavioural intention. We argue that this approach to development and reporting of interventions will contribute to the science of implementation by providing replicable interventions that illuminate the principles and processes underlying change.

title: A Systematic Review Investigating Healthy Lifestyle Interventions Incorporating Goal Setting Strategies for Preventing Excess Gestational Weight Gain
abstract: Excess gestational weight gain (GWG) is an important risk factor for long term obesity in women. However, current interventions aimed at preventing excess GWG appear to have a limited effect. Several studies have highlighted the importance of linking theory with empirical evidence for producing effective interventions for behaviour change. Theorists have demonstrated that goals can be an important source of human motivation and goal setting has shown promise in promoting diet and physical activity behaviour change within non-pregnant individuals. The use of goal setting as a behaviour change strategy has been systematically evaluated within overweight and obese individuals, yet its use within pregnancy has not yet been systematically explored.  To explore the use of goal setting within healthy lifestyle interventions for the prevention of excess GWG.  Searches were conducted in seven databases alongside hand searching of relevant journals and citation tracking. Studies were included if interventions used goal setting alongside modification of diet and/or physical activity with an aim to prevent excess GWG. The PRISMA guidelines were followed and a two-stage methodological approach was used. Stage one focused on systematically evaluating the methodological quality of included interventions. The second stage assessed intervention integrity and the implementation of key goal setting components.  From a total of 839 citations, 54 full-text articles were assessed for eligibility and 5 studies met the inclusion criteria. Among interventions reporting positive results a combination of individualised diet and physical activity goals, self-monitoring and performance feedback indicators were described as active components.  Interventions based on goal setting appear to be useful for helping women achieve optimal weight gain during pregnancy. However, overweight and obese women may require more theoretically-designed interventions. Further high quality, theoretically-designed interventions are required to determine the most effective and replicable components for optimal GWG.

title: Predictors of Pregnancy-Associated Change in Physical Activity in a Rural White Population
abstract: The objective of this study was to examine the relationship of sociodemographic and psychosocial characteristics and exercise prior to pregnancy to change in physical activity (PA) during pregnancy.  This study was part of the Bassett Mothers' Health Project (BMHP), a prospective cohort study of women who enrolled for prenatal care in the Bassett Healthcare system between November 7, 1994, and November 15, 1996. Six hundred twenty-two women met the eligibility criteria and were enrolled in the study. Sociodemographic and psychosocial characteristics and exercise behavior were assessed prenatally using the medical record and an anonymous mailed questionnaire. Staged linear regression analysis was used to predict change in physical activity with the psychosocial and sociodemographic characteristics as the independent variables and prepregnancy exercise frequency as a control variable.  Women who were older, more educated, and had higher household incomes were more likely to exercise prior to pregnancy (p < .05). Change in PA after becoming pregnant was associated with prepregnancy exercise frequency (p < .001). Women who exercised frequently moderated their activity, while sedentary women maintained or increased their PA after becoming pregnant. Exercise self-efficacy (the belief in one's ability to exercise regularly) and body mass index (BMI) were positive predictors of change in PA (p < .05), while prepregnancy exercise frequency remained significant as a control variable.  Interventions that aim to help women maintain or increase their PA during the perinatal period should be designed to increase exercise self-efficacy.

title: Exercise during pregnancy: a review of patterns and determinants.
abstract: The mental and physical health benefits of exercise during pregnancy highlight the importance of understanding the determinants of pregnant women's physical activity. This paper presents a review of the existing research on pregnancy and physical activity, in order to (a) summarize the existing body of literature since 1986 examining changes in physical activity during pregnancy, (b) summarize correlates and predictors of physical activity during pregnancy, and (c) present directions for future research. A literature search yielded 25 articles published from 1986 to 2009 in English peer-reviewed journals. The major findings were categorized into the following: (a) exercise patterns, (b) demographic correlates/predictors, (c) the influence of pre-pregnancy exercise on pregnancy exercise, (d) theory-based predictors and (f) other correlates of exercise (e.g. general health and safety concerns). Results indicated that pregnant women are less active than non-pregnant women and that pregnancy leads to a decrease in physical activity. Consistent demographic predictors of higher exercise participation during pregnancy include higher education and income, not having other children in the home, being white, and being more active prior to becoming pregnancy. Only a few studies used theoretical models to understand physical activity during pregnancy with varied results. The review outlines demographic and theory-based correlates/predictors that should be taken into consideration when developing interventions to increase physical activity among pregnant women.

title: Aerobic exercise for women during pregnancy.
abstract: Physiological responses of the fetus (especially increase in heart rate) to single, brief bouts of maternal exercise have been documented frequently, suggesting that maternal exercise might have beneficial or adverse effects on pregnancy outcome.



The objective of this review was to assess the effects of advising healthy pregnant women to engage in regular (at least two to three times per week) aerobic exercise on physical fitness, labour and delivery, and the outcome of pregnancy.


SEARCH STRATEGY
The Cochrane Pregnancy and Childbirth Group trials register was searched and researchers in the field were contacted. Date of last search: January 2002.



Acceptably controlled comparisons of prescribed aerobic exercise programmes.



One reviewer assessed trial quality and extracted data. Study authors were contacted for additional information.



Ten trials involving 688 women were included. The trials were not of high methodologic quality. Five trials reported significant improvement in physical fitness in the exercise group, although differences in measures used to assess fitness prevent a quantitative pooling of results. Six trials reported on pregnancy outcomes. A statistically significant increased risk of preterm birth (relative risk (RR) = 2.29 [95% confidence interval 1.02 to 5.13]) in the exercise group is inconsistent with the absence of effect on mean gestational age [+0.0 (-0.4 to +0.4) weeks] and may have been biased by post-randomization exclusion of women with preterm labor. Results bearing on fetal growth (birth weight, length, and head circumference) were highly variable. One trial found improvements among exercising women in several aspects of self-reported body image, including muscle strength, energy level, and body build.



Regular aerobic exercise during pregnancy appears to improve (or maintain) physical fitness and body image. Available data are insufficient to infer important risks or benefits for the mother or infant.

title: Use of pedometers and accelerometers in clinical populations: validity and reliability issues
abstract: Pedometers and accelerometers are often used in clinical research studies, and have the potential to provide valid and objective information on physical activity.  The purposes of this review are to introduce clinicians to various activity monitors that are commercially available, and to discuss their strengths and limitations. Scientific articles over the past 20 years were reviewed, and the most common types of physical activity monitors were identified. Emphasis was placed on devices with established validity and reliability, which were acceptable to participants and did not interfere with their activities. Ease-of-use from the investigator's standpoint was also considered.  A number of activity monitors were identified, including four pedometers (Yamax SW digiwalker, New Lifestyles NL-2000, Omron HJ-720 ITC, and StepWatch), three accelerometer-based activity monitors (ActiGraph, Actical, and RT3), and a multisensor device (Sensewear Armband). Validity and reliability of these devices is discussed.  Pedometers and accelerometers are useful for tracking ambulatory physical activity in clinical populations, and those that display steps and/or calories are useful in motivating patients to increase their activity levels.