Can physical activity mitigate the effects of aging in middle-aged women?

Association between Physical Activity, Body Composition, and Metabolic Disorders in Middle-Aged Women of Ksar el Kebir (Morocco)

This study aimed to examine the association between physical activity (PA), body composition, and metabolic disorders in a population of Moroccan women classified by menopausal status. This cross-sectional study comprised 373 peri- and postmenopausal women aged 45-64 years old. PA levels were assessed using the short version of the International Physical Activity Questionnaire (IPAQ-SF). Body composition and metabolic disorders were assessed by measurements of anthropometric and biological parameters: weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), WC/HC ratio, percent body fat, systolic and diastolic blood pressure, fasting blood glucose, and serum lipids (total cholesterol (TC), triglycerides (TG), HDL-C, and LDL-C). Metabolic syndrome (MetS) was diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. Pearson correlations were used to test for associations. The mean total PA score of perimenopausal women was 1683.51 ± 805.36 MET-min/week, and of postmenopausal women was 1450.81 ± 780.67 MET-min/week. In all participants, peri- and postmenopausal women, PA was significantly and inversely associated with BMI, weight, percent body fat, HC, WC, and number of MetS components (p < 0.01), and with fasting blood glucose, TC, TG, and LDL-C (p < 0.05). The frequencies of metabolic disorders, obesity, abdominal obesity, type 2 diabetes, dyslipidemia, and MetS were significantly lower at moderate and intense levels of PA (p < 0.05), in also all participants. In middle-aged women, particularly those who are peri-menopausal, PA at moderate and intense levels is associated with more favorable body composition and less frequent metabolic disorders. However, in this particular study, PA does not appear to be associated with blood pressure and HDL-C concentrations. Future studies may be needed to further clarify these findings.

Physical activity on cardiorespiratory fitness and cardiovascular risk in premenopausal and postmenopausal women: a systematic review of randomized controlled trials

IMPORTANCE

The apparent cardioprotective effects of endogenous estrogens to prevent cardiovascular disease in premenopausal women are reduced with the loss of estrogen post-menopause. Cardiorespiratory fitness and cardiovascular risk factors are closely related to physical activity levels.

OBJECTIVE

This study conducted a critical assessment of studies for health prevention that analyze the effects of physical activity programs on cardiorespiratory fitness and cardiovascular risk factors in women, comparing premenopausal and postmenopausal states, through a systematic review of randomized controlled trials.

EVIDENCE REVIEW

A computerized literature search was performed to include articles up until December 2021 in the following online databases: PubMed, Cochrane, Scopus, SportDiscus, and Web of Science. Regarding physical activity intervention, women of all ages were engaged. The PEDro scale and Oxford's evidence levels were used for the assessment of the risk of bias in the included articles.

FINDINGS

Fourteen scientific articles met the inclusion criteria. Great variability was found in physical activity variables. All the studies found an improvement in at least one variable. The risk of bias was high, with all the articles obtaining a low methodological quality, except two with high methodological quality. Only one article considered the differences in the menopausal state observing the effects of physical activity intervention and highlighting the importance of physical activity in both states.

CONCLUSIONS AND RELEVANCE

To strengthen the evidence for the benefits of physical activity programs in women and to observe the effects depending on their menopausal state, there is an ongoing need for more rigorous randomized controlled trials of appropriate length and dose, with individualized exercise intensity.

Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases

This review provides the reader with the up-to-date evidence-based basis for prescribing exercise as medicine in the treatment of 26 different diseases: psychiatric diseases (depression, anxiety, stress, schizophrenia); neurological diseases (dementia, Parkinson's disease, multiple sclerosis); metabolic diseases (obesity, hyperlipidemia, metabolic syndrome, polycystic ovarian syndrome, type 2 diabetes, type 1 diabetes); cardiovascular diseases (hypertension, coronary heart disease, heart failure, cerebral apoplexy, and claudication intermittent); pulmonary diseases (chronic obstructive pulmonary disease, asthma, cystic fibrosis); musculo-skeletal disorders (osteoarthritis, osteoporosis, back pain, rheumatoid arthritis); and cancer. The effect of exercise therapy on disease pathogenesis and symptoms are given and the possible mechanisms of action are discussed. We have interpreted the scientific literature and for each disease, we provide the reader with our best advice regarding the optimal type and dose for prescription of exercise.

A Scientific Assessment of Sociodemographic Factors, Physical Activity Level, and Nutritional Knowledge as Determinants of Dietary Quality among Indo-Mauritian Women

A healthy diet is of particular concern throughout the life of women to avoid many chronic illnesses especially during their 30s to 50s. There are published data on dietary quality and its determinants among women, but there is a lack of similar data regarding women in Mauritius. This study aimed to investigate the association between age and dietary quality in relation to sociodemographic factors, physical activity level (PAL) and nutritional knowledge (NK). A survey-based study was conducted in 2012 among Indo-Mauritian women including 117 young (21.35 ± 1.98), 160 reaching middle age (34.02 ± 5.09) and 50 middle-aged (37.85 ± 8.32). Validated questionnaires were used to elicit information on the determinants. A food frequency table consisting of 18 food items was used to assess dietary quality. Univariate and multivariate analyses were used to determine the association between various factors and dietary quality. The mean dietary score of middle-aged women (18.70 ± 2.67) was closer to recommended dietary guidelines compared to young women (17.22 ± 3.40), and women reaching middle age (17.55 ± 3.29). Educational level, PAL, NK, and age were main determinants of dietary quality among Indo-Mauritian women (P < 0.05). Younger women with low educational level, PAL, and NK are at risk of poor dietary quality.

Physical activity and cardiovascular risk factors at menopause: the Nord-Trøndelag health study

BACKGROUND

Lowered physical activity levels may partially explain changes in metabolic risk factors in women after menopause.

OBJECTIVES

To evaluate the association between physical activity and metabolic risk factors at baseline and after 11 years, as well as the change in that association over time in women who were premenopausal and ≥ 40 years at baseline.

METHODS

Subjects in a Norwegian population-based health survey answered questionnaires and had body and serum measurements during 1995-1997 (HUNT 2) and in a follow-up study during 2006-2008 (HUNT 3). Repeated-measures analyses were used to estimate the association between physical activity and metabolic factors, adjusting for age, smoking status, education, alcohol intake, and parity. Adjustment for hormonal treatment and medication was made, as appropriate.

RESULTS

In women remaining premenopausal, a higher physical activity score in HUNT 3 was associated with lower weight (p < 0.01) and waist-hip ratio (p < 0.01) and higher high density lipoprotein (HDL) cholesterol in HUNT 3 (p < 0.01). In women that were postmenopausal by the time of follow-up, a higher physical activity score in HUNT 3 was associated with lower weight (p < 0.01), waist-hip ratio (p < 0.01), triglycerides (p < 0.01), and higher total cholesterol (p < 0.05), HDL cholesterol (p < 0.01), and diastolic blood pressure (p < 0.05) in HUNT 3. The association of total physical activity score with weight and waist-hip ratio was stronger in HUNT 3 than in HUNT 2 (p < 0.01).

CONCLUSION

Increased physical activity may reduce the risk of adverse outcomes and use of pharmacological management in women of menopausal age.

Effects of the menopausal transition on energy expenditure: a MONET Group Study

Objectives

Factors that influence weight gain during the menopausal transition are not fully understood. The purpose of this study was to investigate changes in energy expenditure (EE) across the menopausal transition.

Methods

One hundred and two premenopausal women (age: 49.9 ± 1.9 yrs; BMI: 23.3 ± 2.2 kg/m²) were followed for 5 years. Body composition (DXA), physical activity EE (accelerometer), resting EE and thermic effect of food (indirect calorimetry) were measured annually.

Results

Total EE decreased significantly over time in postmenopausal women (P < 0.05), which was mostly due to a decrease in physical activity EE (P < 0.05). Although average resting EE remained stable over time in postmenopausal women, a significant increase, over the 5-year period, was noted in women who were in the menopausal transition by year 5 (P < 0.05). Finally, the time spent in moderate physical activity decreased and the time spent in sedentary physical activity increased during the menopausal transition (P < 0.05).

Conclusion

These results suggest that menopausal transition is accompanied with a decline in EE mainly characterized by a decrease in physical activity EE and a shift to a more sedentary lifestyle.

Physical activity, weight, and waist circumference in midlife women

During midlife years, women are at risk of increasing body weight and waist circumference. We evaluated changes in weight and waist circumference from enrollment to 2 years later and examined the influence of physical activity level on those changes among 232 women aged between 40 and 50. Weight increased significantly for the entire sample. Those who increased their physical activity from enrollment to 2 years later had the smallest increase in weight and had a slight decrease in waist circumference. To maintain ideal weight and waist circumference, midlife women should be encouraged to increase physical activity before and during the menopausal transition.

Body mass index in multiethnic midlife women: influence of demographic characteristics and physical activity

We examined the influence of demographic characteristics and physical activity on body mass index (BMI) in multiethnic midlife women. A sample of 236 African, European, and Mexican/Central Americans aged 40-50 completed the initial, 1-year, and 2-year assessments. The effects of demographic characteristics and physical activity on BMI at the 2-year assessment were evaluated using hierarchical multiple regression analysis. After controlling for other demographic factors, ethnicity, annual household income, and physical activity at the initial assessments were significant predictors of BMI. Body mass index (BMI) may be influenced by socioeconomic status as well as ethnicity. Regular physical activity should be encouraged to maintain a healthy BMI in midlife women.

Physical activity and health during the menopausal transition

The benefits of regular physical activity are well established, but evidence for a protective effect against the adverse health consequences accompanying the menopausal transition is limited. This article reviews that evidence, concluding that more physical activity is generally associated with fewer somatic and mood symptoms. Physical activity seems to minimize weight gain and changes in body composition and fat distribution experienced at midlife and might attenuate the rapid bone density loss that occurs. Given these benefits, clinicians treating perimenopausal women should encourage their patients to follow guidelines for physical activity (≥150 minutes a week of moderate-intensity activity).

Rebranding exercise: closing the gap between values and behavior

BACKGROUND

Behavior can only be understood by identifying the goals to which it is attached. Superordinate-level goals are linked to individuals' values, and may offer insights into how to connect exercise with their core values and increase participation in sustainable ways.

METHODS

A random sample of healthy midlife women (aged 40-60y) was selected to participate in a year-long mixed-method study (n = 226). Superordinate goals were measured inductively and analyzed using grounded theory analysis. Attainment Value and Exercise Participation were quantitatively measured. An ANOVA and pairwise comparisons were conducted to investigate the differences between superordinate exercise goals in attainment value. This study fit a Linear Mixed Model to the data to investigate the fixed effects of superordinate goals on exercise participation, controlling for BMI and social support.

RESULTS

Participants mainly exercised to achieve Healthy-Aging, Quality-of-Life, Current-Health, and Appearance/Weight superordinate goals. Despite equally valuing Healthy-Aging, Quality-of-Life, and Current-Health goals, participants with Quality-of-Life goals reported participating in more exercise than those with Current-Health (p < 0.01), and Healthy-Aging (p = 0.06) goals.

CONCLUSIONS

Superordinate exercise goals related to health and healthy aging are associated with less exercise than those related to enhancing daily quality of life, despite being equally valued. While important, pursuing distant benefits from exercise such as health promotion, disease prevention, and longevity might not be as compelling to busy individuals compared to their other daily priorities and responsibilities. By shifting our paradigm from medicine to marketing, we can glean insights into how we can better market and "sell" exercise. Because immediate payoffs motivate behavior better than distant goals, a more effective "hook" for promoting sustainable participation might be to rebrand exercise as a primary way individuals can enhance the quality of their daily lives. These findings have important implications for how we as a culture, especially those in fitness-related businesses, health promotion, health care, and public health, prescribe and market exercise on individual and population levels.

Eight-month follow-up of physical activity and central adiposity: results from an Internet-delivered randomized control trial intervention

BACKGROUND

Less than half of U.S. adults engage in the recommended amount of physical activity (PA). Internet-delivered PA programs increase short-term PA but long-term adherence is largely equivocal.

PURPOSE

To determine whether increased PA following the 16-week Internet-delivered Active Living Every Day (ALED-I) program is maintained 8 months later in sedentary and overweight rural adults.

METHODS

In our previous randomized controlled trial (N = 32; 18 intent-to-treat controls, 14 ALED-I interventions), the ALED-I group increased PA (+1384 steps/day; E.S. = 0.95) and reduced central adiposity. Nine original intervention participants and ten delayed intent-to-treat control participants completed ALED-I and an 8-month followup. Pedometer-measured PA, anthropometric variables, and cardiometabolic disease risk factors were assessed at baseline, postintervention, and at 8 months.

RESULTS

Control crossover participants increased PA (+1337 steps/ day; P = .04). Eight months following completion of ALED-I (N = 19), PA levels relapsed (-1340 steps/day) and were similar to levels before the intervention (6850 +/- 471 steps/day vs. 6755 +/- 543 steps/day; P = .89). Total cholesterol and triglycerides improved, -9.9% and -18.2%, respectively, and reductions in central adiposity were maintained (97.1 +/- 2.2 cm vs. 97.2 +/- 2.2 cm; P = .66).

CONCLUSIONS

The ALED-I intervention was efficacious in the short-term but did not produce longer-term adherence to PA. Future theory-based internet-delivered interventions that produce habituation of increased PA are warranted.

Physical activity patterns and prevention of weight gain in premenopausal women

BACKGROUND

Studies of the association between physical activity (PA) and weight maintenance have been inconsistent.

METHODS

We prospectively examined the association between PA patterns and prevention of weight gain among 46,754 healthy premenopausal women, aged 25–43 years in 1989. Participants reported their PA and weight in 1989 and 1997. The primary outcome was gaining >5% of baseline weight by 1997 (62% of the population).

RESULTS

Compared with women who maintained <30 minutes/day of total discretionary activity over 8 years, women were less likely to gain weight if they sustained 30+ minutes/day (Odds Ratio OR=0.68, 95% confidence interval [CI] 0.64–0.73) or increased to 30+ minutes/day in 1997 (OR=0.64, 95%CI=0.60–0.68). Among women whose only reported activity was walking, risk of gaining weight was lower in those who sustained 30+ minutes/day over 8 years (OR=0.66, 95%CI=0.49–0.91), and brisk walking pace independently predicted less weight gain. For a 30 minutes/day increase between 1989 and 1997, jogging/running was associated with less weight gain than brisk walking or other activities. Greater duration of PA was associated with progressively less weight gain, but even an 11–20 minutes/day increase was beneficial; the benefits appeared stronger among those initially overweight. Sedentary behavior independently predicted weight gain.

CONCLUSIONS

Sustained PA for at least 30 minutes/day, particularly if more intense, is associated with a reduction in long-term weight gain, and greater duration is associated with less weight gain. Sedentary women of any baseline weight who increase their PA will benefit, but overweight women appear to benefit the most.

American College of Sports Medicine Position Stand. Appropriate physical activity intervention strategies for weight loss and prevention of weight regain for adults

Overweight and obesity affects more than 66% of the adult population and is associated with a variety of chronic diseases. Weight reduction reduces health risks associated with chronic diseases and is therefore encouraged by major health agencies. Guidelines of the National Heart, Lung, and Blood Institute (NHLBI) encourage a 10% reduction in weight, although considerable literature indicates reduction in health risk with 3% to 5% reduction in weight. Physical activity (PA) is recommended as a component of weight management for prevention of weight gain, for weight loss, and for prevention of weight regain after weight loss. In 2001, the American College of Sports Medicine (ACSM) published a Position Stand that recommended a minimum of 150 min wk(-1) of moderate-intensity PA for overweight and obese adults to improve health; however, 200-300 min wk(-1) was recommended for long-term weight loss. More recent evidence has supported this recommendation and has indicated more PA may be necessary to prevent weight regain after weight loss. To this end, we have reexamined the evidence from 1999 to determine whether there is a level at which PA is effective for prevention of weight gain, for weight loss, and prevention of weight regain. Evidence supports moderate-intensity PA between 150 and 250 min wk(-1) to be effective to prevent weight gain. Moderate-intensity PA between 150 and 250 min wk(-1) will provide only modest weight loss. Greater amounts of PA (>250 min wk(-1)) have been associated with clinically significant weight loss. Moderate-intensity PA between 150 and 250 min wk(-1) will improve weight loss in studies that use moderate diet restriction but not severe diet restriction. Cross-sectional and prospective studies indicate that after weight loss, weight maintenance is improved with PA >250 min wk(-1). However, no evidence from well-designed randomized controlled trials exists to judge the effectiveness of PA for prevention of weight regain after weight loss. Resistance training does not enhance weight loss but may increase fat-free mass and increase loss of fat mass and is associated with reductions in health risk. Existing evidence indicates that endurance PA or resistance training without weight loss improves health risk. There is inadequate evidence to determine whether PA prevents or attenuates detrimental changes in chronic disease risk during weight gain.

Getting Tougher for the Fourth Quarter: Boomers and Physical Activity

Baby Boomers might not consider themselves as growing old but are starting to reach the last quarter of average life spans. This article asks how Boomers prepare for their fourth quarters through physical activity. Three years (1999–2001) of National Health Interview Survey data yielded 96,501 adult respondents. Dependent variables were moderate, vigorous, and strengthening activity. Old boomers (1946–1955) and young boomers (1956–1965) were compared to respondents born before 1926, after 1975, and 10-year cohorts between. SUDAAN multiple logistic regression adjusted for complex sampling structure and multiply imputed income. Age-adjusted, older cohorts showed greater likelihood of activity than younger cohorts, offsetting moderate-activity declines with age until sharp decreases at advanced age: a plateau across Boomer and younger-aged cohorts. Interventions should promote activity at intensities and frequencies to which Boomers are most receptive.

Internet-delivered behavior change program increases physical activity and improves cardiometabolic disease risk factors in sedentary adults: results of a randomized controlled trial

OBJECTIVES

To determine whether the Active Living Every Day (ALED-I) internet-delivered theory-based physical activity (PA) behavior change program increases PA and improves cardiometabolic disease risk factors (CDRF) in sedentary overweight adults.

METHODS

The study was a randomized control trial that took place in southern Wyoming and northern Colorado from 2005-2007. Thirty-two men and women (21-65 years) were randomized to a 16-week ALED-I intervention (n=14; age=41.4+/-3.7 years; BMI=32.3+/-1.3 kg/m(2)) or a delayed intent-to-treat control condition (n=18; age=49.4+/-1.7 years; BMI=30.6+/-0.8 kg/m(2)). At baseline and post-intervention, PA by pedometer and CDRFs were measured.

RESULTS

Both groups had similar baseline PA levels. ALED-I increased PA by an average of 1384 steps/day (p=0.03) compared to 816 steps/day (p=0.14) for the control group. Waist circumference (100.6+/-2.4 vs. 96.6+/-2.7 cm) and Coronary Risk Ratio (5.1+/-0.3 vs. 4.7+/-0.3) decreased in the ALED-I group and did not change in the control group (99.2+/-2.2 vs.99.8+/-2.1 cm) and (3.7+/-0.1 vs. 3.7+/-0.1), respectively.

CONCLUSIONS

The internet-delivered ALED program increased PA and improved some CDRFs in sedentary overweight/obese adults. To our knowledge, this is the first efficacy trial of the internet-delivered ALED program. Further studies are warranted due to the reach and cost-effectiveness of internet-delivered PA programs.

Asymmetric weight gain and loss from increasing and decreasing exercise

PURPOSE

Although increases and decreases in physical activity are known to cause weight loss and weight gain, respectively, it is not known whether the magnitudes of these changes in weight are equal. Unequal (asymmetric) weight changes could contribute to overall weight gain or loss among individuals with seasonal or irregular activity.

METHODS

Changes in adiposity were compared with the running distances at baseline and follow-up in men and women whose reported exercise increased (N = 4632 and 1953, respectively) or decreased (17,280 and 5970, respectively) during 7.7 yr of follow-up.

RESULTS

Per km.wk(-1) decreases in running distance caused more than four times greater weight gain between 0 and 8 km.wk(-1) (slope +/- SE, males: -0.068 +/- 0.005 kg.m(-2); females: -0.080 +/- 0.01 kg.m(-2)) than between 32 and 48 km.wk(-1) (-0.017 +/- 0.002 and -0.010 +/- 0.005 kg.m(-2), respectively). In contrast, increases in running distance produced the smallest weight losses between 0 and 8 km.wk(-1) and statistically significant weight loss only above 16 km.wk(-1). Above 32 km.wk(-1) (30 kcal.kg(-1)) in men and 16 km.wk(-1) (15 kcal.kg(-1)) in women, weight loss from increasing exercise was equal to or greater than weight gained from decreasing exercise; otherwise, weight gain exceeded weight loss.

CONCLUSION

Weight gained because of reductions in weekly exercise below 30 kcal.kg(-1) in men and 15 kcal.kg(-1) in women may not be reversed by resuming prior activity. Current IOM guidelines (i.e., maintain total energy expenditure at 160% of basal) agree with the men's exercise threshold for symmetric weight change with changing exercise levels. Asymmetric weight changes below this threshold may contribute to weight gain among less-active subjects.

Effects of a community-based healthy heart program on increasing healthy women's physical activity: a randomized controlled trial guided by Community-based Participatory Research (CBPR)

Background

Cardiovascular disease remains the leading killer of women in most developed areas of the world. Rates of physical inactivity and poor nutrition, which are two of the most important modifiable risk factors for cardiovascular disease in women, are substantial. This study sought to examine the effectiveness of a community-based lifestyle-modification program on increasing women's physical activity in a randomized trial guided by community-based participatory research (CBPR) methods.

Methods

A total of 335 healthy, 25–64 years old women who had been selected by a multiple-stage stratified cluster random sampling method in Bushehr Port/I.R. Iran, were randomized into control and intervention groups. The intervention group completed an 8-week lifestyle modification program for increasing their physical activity, based on a revised form of Choose to Move program; an American Heart Association Physical Activity Program for Women. Audio-taped activity instructions with music and practical usage of the educational package were given to the intervention group in weekly home-visits by 53 volunteers from local non-governmental and community-based organizations.

Results

Among the participants, the percentage who reported being active (at lease 30 minutes of moderate intensity physical activity for at least 5 days a week, or at least 20 minutes of vigorous physical activity for at least three days a week) increased from 3% and 2.7% at baseline to 13.4% and 3% (p < 0.0001) at the ending of the program in the intervention and control groups, respectively. The participants in the intervention group reported more minutes of physical activity per week (mean = 139.81, SE = 23.35) than women in the control group (mean = 40.14, SE = 12.65) at week 8 (p < 0.0001). The intervention group subjects exhibited a significantly greater decrease in systolic blood pressure (-10.0 mmHg) than the control group women (+2.0. mmHg). The mean ranks for posttest healthy heart knowledge in the intervention and control groups were 198.91 and 135.77, respectively (P < 0.0001).

Conclusion

An intervention based on CBPR methods can be effective for the short-term adoption of physical activity behavior among women. The development of participatory process to support the adequate delivery of lifestyle-modification programs is feasible and an effective healthcare delivery strategy for cardiovascular community health promotion.

Trial Registration

ACTRNO12606000521527

Maintaining vigorous activity attenuates 7-yr weight gain in 8340 runners

INTRODUCTION/PURPOSE

Body weight generally increases with aging in Western societies. Although training studies show that exercise produces acute weight loss, it is unclear whether the long-term maintenance of vigorous exercise attenuates the trajectory of age-related weight gain. Specifically, prior studies have not tested whether the maintenance of physical activity, in the absence of any change in activity, prevents weight gain.

METHODS

Prospective study of 6119 male and 2221 female runners whose running distances changed < 5 km x wk(-1) between baseline and follow-up surveys 7 yr later.

RESULTS

On average, men who maintained modest (0-23 km x wk(-1)), intermediate (24-47 km x wk(-1)), or prolonged running distances (> or = 48 km x wk(-1)) all gained weight through age 64; however, those who maintained > or = 48 km x wk(-1) had one half the average annual weight gain of those who maintained < 24 km x wk(-1). For example, between the ages of 35 and 44 in men and 30 and 39 yr in women, those who maintained < 24 km x wk(-1) gained, on average, 2.1 and 2.9 kg more per decade than those averaging > 48 km x wk(-1). Age-related weight gain, and its attenuation by maintained exercise, were both greater in younger than in older men. Men's gains in waist circumference with age, and its attenuation by maintaining running, were the same in older and younger men. Regardless of age, women increased their body weight, waist circumference, and hip circumference over time, and these measurements were attenuated in proportion to their maintained running distance. In both sexes, running disproportionately prevented more extreme increases in weight.

CONCLUSION

As they aged, men and women gained less weight in proportion to their levels of sustained vigorous activity. This long-term beneficial effect is in addition to the acute weight loss that occurs with increased activity.

Body mass, DRD4, physical activity, sedentary behavior, and family socioeconomic status: the add health study

OBJECTIVE

To investigate the joint role of the 48-base pair repeat polymorphism of the dopamine receptor 4 gene (DRD4) and environmental factors in body mass variation among an ethnically diverse sample of U.S. adolescents and young adults.

RESEARCH METHODS AND PROCEDURES

Approximately 2600 adolescent and young adults in the National Longitudinal Study of Adolescent Health (Add Health) who provided DNA measures and measures of height and weight were included in the analysis. Mixed regression modeling was used to investigate the effects of the 7R/7R and any5R variants in the DRD4 gene simultaneously with the effects of physical activity (PA), sedentary behavior (SB), and family socioeconomic status (SES) on body mass variation. European Americans, African Americans, and Hispanic Americans were modeled separately.

RESULTS AND DISCUSSION

Both the 7R/7R and any5R genotypes of the DRD4 gene were associated with age- and sex-specific BMI percentile score (BMI-P) based on the Centers for Disease Control and Prevention/National Center for Health Statistics 2000 reference curves among African Americans and only among African Americans (N = 413) 20 years old or younger. Neither genetic variants are associated with the BMI measure among white (N = 1386) and Hispanic-American (N = 331) adolescents. The presence of the 7R/7R genotype was associated with a reduction of 15.1 in BMI percentile (p = 0.005), and the presence of any5R was associated with an increase of 15.5 in BMI percentile (p = 0.003), after adjusting for PA, SB, and family SES. Neither PA nor SB as measured in Add Health is importantly associated with BMI-P, suggesting a complex relationship between body mass and PA/SB among adolescents and young adults. Family SES is negatively related to BMI-P in the European-American sample.

Does the hormonal situation modify lipid effects by lifestyle factors in middle-aged women? Results from a population-based study of Swedish women: the women's health in the Lund area study

The aim of the study was to outline whether the influence by lifestyle factors on serum lipids was modified by the hormonal situation in middle-aged women. Six thousand nine hundred eight women, aged 50 to 59 years, participated in a health assessment program, including a serum lipid profile evaluation. The women were grouped according to their hormonal status into premenopausal (PM) (n = 492), postmenopausal without hormone therapy (HT) (PM0) (n = 3600), and postmenopausal with HT (PMT) (n = 2816). From the PMT group, we analyzed oral (n = 901) and transdermal HT (n = 351) regimens, containing norethisterone acetate and 17beta-estradiol. Serum lipids and lipoproteins were determined by conventional methods. Lifestyle factors included smoking and physical activity at leisure time and at work. Multivariate linear regression analysis controlling for age, education, and dietary habits showed that current smoking was positively associated with triglycerides in the PM, PM0, PMT, and oral HT groups. In the PM0, PMT, and oral HT groups, current smoking was positively associated with total cholesterol and low-density lipoprotein and negatively associated with high-density lipoprotein (HDL). Low physical activity at leisure time was positively associated with triglycerides in the PM and PMT groups and negatively associated with HDL in the PM0 and PMT groups. High physical activity at work was positively associated with triglycerides in the PMT group and with total cholesterol in the PM0 group, but negatively associated with HDL in the PMT and transdermal groups. Body mass index was positively associated with triglycerides and negatively with HDL in all the groups regardless of the hormonal situation. The serum lipid profile as influenced by lifestyle factors was modified by the hormonal situation. Compared with the postmenopausal women without HT use, the use of HT contributes to fewer "negative" effects by lifestyle factors on serum lipids.

Prospective associations between sedentary lifestyle and BMI in midlife

OBJECTIVE

A strong positive cross-sectional relationship between BMI and a sedentary lifestyle has been consistently observed in numerous studies. However, it has been questioned whether high BMI is a determinant or a consequence of a sedentary lifestyle.

RESEARCH METHODS AND PROCEDURES

Using data from four follow-ups of the University of North Carolina Alumni Heart Study, we examined the prospective associations between BMI and sedentary lifestyle in a cohort of 4595 middle-aged men and women who had responded to questionnaires at the ages of 41 (standard deviation 2.3), 44 (2.3), 46 (2.0), and 54 (2.0).

RESULTS

BMI was consistently related to increased risk of becoming sedentary in both men and women. The odds ratios of becoming sedentary as predicted by BMI were 1.04 (95% confidence limits, 1.00, 1.07) per 1 kg/m(2) from ages 41 to 44, 1.10 (1.07, 1.14) from ages 44 to 46, and 1.12 (1.08, 1.17) from ages 46 to 54. Controlling for concurrent changes in BMI marginally attenuated the effects. Sedentary lifestyle did not predict changes in BMI, except when concurrent changes in physical activity were taken into account (p < 0.001). The findings were not confounded by preceding changes in BMI or physical activity, age, smoking habits, or sex.

DISCUSSION

Our findings suggest that a high BMI is a determinant of a sedentary lifestyle but did not provide unambiguous evidence for an effect of sedentary lifestyle on weight gain.

Evidence for prescribing exercise as therapy in chronic disease

Considerable knowledge has accumulated in recent decades concerning the significance of physical activity in the treatment of a number of diseases, including diseases that do not primarily manifest as disorders of the locomotive apparatus. In this review we present the evidence for prescribing exercise therapy in the treatment of metabolic syndrome-related disorders (insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity), heart and pulmonary diseases (chronic obstructive pulmonary disease, coronary heart disease, chronic heart failure, intermittent claudication), muscle, bone and joint diseases (osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, chronic fatigue syndrome) and cancer, depression, asthma and type 1 diabetes. For each disease, we review the effect of exercise therapy on disease pathogenesis, on symptoms specific to the diagnosis, on physical fitness or strength and on quality of life. The possible mechanisms of action are briefly examined and the principles for prescribing exercise therapy are discussed, focusing on the type and amount of exercise and possible contraindications.

Weight gain over 5 years in 21 966 meat-eating, fish-eating, vegetarian, and vegan men and women in EPIC-Oxford

BACKGROUND

Cross-sectional studies have shown that vegetarians and vegans are leaner than omnivores. Longitudinal data on weight gain in these groups are sparse.

OBJECTIVE

We investigated changes in weight and body mass index (BMI) over a 5-year period in meat-eating, fish-eating, vegetarian, and vegan men and women in the UK.

DESIGN

Self-reported anthropometric, dietary and lifestyle data were collected at baseline in 1994-1999 and at follow-up in 2000-2003; the median duration of follow-up was 5.3 years.

SUBJECTS

A total of 21,966 men and women participating in Oxford arm of the European Prospective Investigation into Cancer and Nutrition aged 20-69 years at baseline.

RESULTS

The mean annual weight gain was 389 (SD 884) g in men and 398 (SD 892) g in women. The differences between meat-eaters, fish-eaters, vegetarians and vegans in age-adjusted mean BMI at follow-up were similar to those seen at baseline. Multivariable-adjusted mean weight gain was somewhat smaller in vegans (284 g in men and 303 g in women, P<0.05 for both sexes) and fish-eaters (338 g, women only, P<0.001) compared with meat-eaters. Men and women who changed their diet in one or several steps in the direction meat-eater --> fish-eater --> vegetarian --> vegan showed the smallest mean annual weight gain of 242 (95% CI 133-351) and 301 (95% CI 238-365) g, respectively.

CONCLUSION

During 5 years follow-up, the mean annual weight gain in a health-conscious cohort in the UK was approximately 400 g. Small differences in weight gain were observed between meat-eaters, fish-eaters, vegetarians and vegans. Lowest weight gain was seen among those who, during follow-up, had changed to a diet containing fewer animal food.

Nonlinear relationships between weekly walking distance and adiposity in 27,596 women

INTRODUCTION/PURPOSE

Data from vigorously active women (runners) suggested that declines in adiposity with weekly running distance were nonlinear and dependent on whether the women are relatively lean or fat. The purpose of the current study is to assess the cross-sectional relationship between the amount of moderate-intensity physical activity (walking distance) and indicators of adiposity.

METHODS

Cross-sectional analyses (i.e., quadratic polynomial regression, regression for percentiles of adiposity) of body mass index (BMI), body circumferences, and bra cup sizes in 27,596 women.

RESULTS

The estimated percent reductions between walking 40-50 km.wk(-1) and <10 km.wk(-1) were greatest for BMI, intermediate for waist circumference and cup size, and least for hip and chest circumferences. The relationships of walking distance to BMI and body circumferences were all nonlinear (convex). In addition, the inverse relationship between weekly walking distance and adiposity was greatest at the highest percentile of BMI, body circumferences, and cup size, and least at the lowest percentiles. Thus, the decline in adiposity per kilometer per week increment in walking distance was greatest in overweight mostly sedentary women and least in lean active women. The decline in BMI per kilometer per week of exercise was greater in the walkers than previously reported for runners. However, based on the relationships between walking distance and percentiles of the BMI distribution reported here, we show that the majority of this difference is attributable to the leanness of the runners and greater fatness of the walker.

CONCLUSION

These data suggest that in women the greatest benefit of walking may be among the most obese and that at higher weekly distances the declines in weight associated with walking diminish. Whether these relationships are causal remains to be determined.

Relationships of age and weekly running distance to BMI and circumferences in 41,582 physically active women

OBJECTIVE

To assess in women whether age-related increases in adiposity are dependent on exercise, and, contrariwise, whether exercise-related declines in adiposity are dependent on age.

RESEARCH METHODS AND PROCEDURES

Cross-sectional analyses were conducted of 41,582 female runners.

RESULTS

Age affected the relationships between vigorous exercise and adiposity. The decline in BMI per kilometer per week run was linear in 18 to 23 year olds and became increasingly non-linear (convex) with age. Waist, hip, and chest circumferences declined significantly with running distance across all age groups, but the declines were significantly greater in older than younger women, particularly among shorter distance runners. The relationships between body circumferences and running distance became increasingly convex in older women. Conversely, vigorous exercise diminished the apparent increase in adiposity with age. The increase in average BMI with age was greatest in women who ran <8 km/wk, intermediate in women who ran 8 to 15 km/wk or 16 to 31 km/wk, and least in those who averaged over 32 km/wk. Before age 45, waist circumference rose for those who ran 0 to 7 km/wk, showed no significant relationship to age for those who ran 8 to 39 km/wk, and declined in those who ran 40 to 55 and 56 km/wk and more. Age related-increases in hip and chest circumferences before 45 years old were significantly less in women who ran longer weekly distances.

DISCUSSION

These cross-sectional associations are consistent with the hypothesis that exercise may mitigate age-related increases in adiposity and that age affects exercise-induced reductions in adiposity (although causality remains to be determined experimentally).

Relation between the changes in physical activity and body-mass index during adolescence: a multicentre longitudinal study

BACKGROUND

The role of physical activity in preventing obesity during adolescence remains unknown. We examined changes in activity in relation to changes in body-mass index (BMI) and adiposity in a cohort of 1152 black and 1135 white girls from the USA, who were followed up prospectively from ages 9 or 10 to 18 or 19 years.

METHODS

BMI and sum of skinfold thickness were assessed annually, whereas habitual activity was assessed at years 1 (baseline), 3, 5, and 7-10. Each girls' overall activity status was categorised as active, moderately active, or inactive. Longitudinal regression models examined associations between changes in activity and in overall activity status with changes in BMI and in sum of skinfold thickness.

FINDINGS

Each decline in activity of 10 metabolic equivalent [MET]-times per week was associated with an increase in BMI of 0.14 kg/m2 (SE 0.03) and in sum of skinfold thickness of 0.62 mm (0.17) for black girls, and of 0.09 kg/m2 (0.02) and 0.63 mm (0.13) for white girls. At ages 18 or 19 years, BMI differences between active and inactive girls were 2.98 kg/m2 (p<0.0001) for black girls and 2.10 kg/m2 (p<0.0001) for white girls. Similar results were apparent for sum of skinfold thickness. For moderately active girls, changes in BMI and sum of skinfold thickness were about midway between those for active and inactive girls.

INTERPRETATION

Changes in activity levels of US girls during adolescence significantly affected changes in BMI and adiposity. Thus, preventing the steep decline in activity during adolescence is an important method to reduce obesity.

Menopause, Physical Activity, and Body Composition/Fat Distribution in Midlife Women

PURPOSE

Hormonal changes associated with menopause, chronological aging, and lifestyle, specifically physical activity, may all influence the changes in body composition and fat distribution experienced by midlife women. This cross-sectional study examined those relations in a representative sample of 248 white and Chinese women, ages 47-57, participating in an ancillary study to the Study of Women's Health Across the Nation (SWAN), a multi-center, longitudinal investigation of the natural history of the menopause in a racially/ethnically diverse cohort.

METHODS

Body composition (lean mass, percent body fat) was assessed with dual energy x-ray absorptiometry, and central adiposity was determined by waist circumference. Physical activity was assessed from 7 d of accelerometer recordings. Menopausal status was based on self-reported bleeding patterns.

RESULTS

Higher levels of physical activity, particularly vigorous-intensity activity, were generally independently associated with decreased percent body fat and smaller waist circumference, although these findings were not statistically significant in the Chinese women. Among the white women, every half a standard deviation increase in total activity was associated with a 1.6-point decrease in percent body fat (P = 0.002). Waist circumference decreased from 96.2 cm (SE = 1.04) in those doing no vigorous-intensity activity to 81.4 cm (SE = 1.05) in those doing 10 min or more a day (P for trend = 0.05). For both the whites and the Chinese, late peri- and postmenopausal status was associated with lower lean mass, and among the Chinese, tended to be associated with higher percent body fat.

CONCLUSION

These findings suggest that regular physical activity may help to mitigate the tendency for weight gain and adverse changes in body composition and fat distribution that accompany aging and the menopausal transition.

Non-exercise activity thermogenesis (NEAT)

Non-exercise activity thermogenesis (NEAT) is the energy expended for everything we do that is not sleeping, eating or sports-like exercise. NEAT can be measured by one of two approaches. The first approach is to measure or estimate total NEAT. Here, total daily energy expenditure is measured and from it, the basal metabolic rate-plus-thermic effect of food is subtracted. The second approach is the factoral approach whereby the components of NEAT are quantified and total NEAT calculated by summing these components. The amount of NEAT that humans perform represents the product of the amount and types of physical activities and the thermogenic cost of each activity. The factors that impact a human's NEAT are readily divisible in biological factors such as weight, gender and body composition and environmental factors such occupation or dwelling within a "concrete jungle." The impact of these factors combined explains the substantial variance in human NEAT. The variability in NEAT might be viewed as random and unprogrammed but human data contradict this thesis. It appears that changes in NEAT accompany experimentally induced changes in energy balance and may be important in the physiology of weight change. NEAT and a sedentary lifestyle may thus be of profound importance in obesity.

A dietary and exercise intervention slows menopause-associated progression of subclinical atherosclerosis as measured by intima-media thickness of the carotid arteries

OBJECTIVES

The object of this study was to assess the effects of menopause and a diet/exercise intervention on subclinical atherosclerosis progression.

BACKGROUND

Subclinical atherosclerosis has been linked to higher coronary heart disease and stroke rates and is greater among postmenopausal women according to cross-sectional analyses. Whether menopause is associated with an accelerated progression of subclinical disease is unknown, as is the extent to which lifestyle intervention can alter the course of progression.

METHODS

Intima-media thickness (IMT) measures of the common carotid artery (CCA), internal carotid artery (ICA), and bulb segments of the carotid arteries were measured twice during the course of 4 years in 353 women from the Women's Healthy Lifestyle Project, a dietary and exercise clinical trial designed to prevent adverse risk factor changes through the menopause. A third measure was obtained 2.5 years later for 113 women.

RESULTS

The progression of IMT was observed for the average of all segments (AVG), the CCA, and the bulb (0.007 mm/year, 0.008 mm/year, and 0.012 mm/year; p < 0.01 for all), but not for the ICA. Among controls, menopause was associated with accelerated IMT progression (0.003 mm/year for premenopausal women vs. 0.008 mm/year for perimenopausal/postmenopausal women for AVG IMT; p = 0.049). Additionally, among the 160 perimenopausal/postmenopausal women, the intervention slowed IMT progression (0.008 mm/year for the control group vs. 0.004 mm/year for the intervention group for AVG IMT; p = 0.02). Similar results were found for the CCA and bulb segments.

CONCLUSIONS

These data demonstrate that the menopause transition is associated with accelerated subclinical atherosclerosis progression and that a diet/exercise intervention slows menopause-related atherosclerosis progression.

Reducing cardiovascular risk factors in postmenopausal women through a lifestyle change intervention

BACKGROUND

The impact of a 6-month lifestyle change intervention on cardiovascular risk factors in obese, sedentary, postmenopausal women was examined. A secondary aim of this investigation was to determine whether the addition of self-control skills training to an empirically supported lifestyle change intervention would result in greater cardiovascular risk reduction.

METHODS

Forty-four women were randomly assigned to receive either a lifestyle change or a lifestyle change with self-control skills intervention. Pretreatment and posttreatment weight loss, body composition, physical activity, cardiorespiratory fitness, diet, blood pressure (BP), blood lipids, and psychosocial functioning were assessed. Also, at 1-year posttreatment, weight loss, body composition, self-reported physical activity, and psychosocial functioning were assessed.

RESULTS

The women significantly increased their physical activity (+39.6%) and cardiorespiratory fitness (+13.5%) and reduced their body weight (-6.5%), fat mass (-7.4%), body fat (-2.4%), BP (SBP -6.2%, DBP -9.2%), total cholesterol (-7.4%), triglycerides (-16.5%), and low-density lipoprotein (LDL) cholesterol (9.1%) and improved their diet (p < 0.05). At the 1-year follow-up, women had regained approximately 63% of their posttreatment weight loss (p < 0.05), but had maintained their previous increases in physical activity. Additionally, there were no significant changes in fat free mass, body fat, anxiety, or depression between the end of treatment and 1-year posttreatment. The addition of self-control skills training did not significantly improve cardiovascular risk reduction.

CONCLUSIONS

Lifestyle change interventions may be an effective means for reducing cardiovascular risk in obese, sedentary, postmenopausal women. However, greater attention should be devoted to the maintenance of these positive lifestyle changes.

Longitudinal study of the long-term relation between physical activity and obesity in adults

BACKGROUND

Earlier observational studies of the relation between physical activity and obesity are inconsistent and ambiguous, showing a clear cross-sectional inverse relation, and a prospective association only when physical activity at the time of follow-up is included.

OBJECTIVE

To examine the long-term effect of leisure time physical activity (LTPA) on subsequent development of obesity and the effect of body weight on later physical inactivity in a population-based longitudinal setting taking into account the effects of historical changes on future changes as well as pertinent confounders.

DESIGN

The study included 3653 women and 2626 men aged 20-78 y selected at random within sex-age strata from the general population of Copenhagen. At two surveys, 5 y apart, LTPA, body mass index (BMI) (weight/height2, kg/m2), several possible confounders and modifying factors were assessed. Obesity (defined as BMI > or =30 kg/m2) and LTPA was assessed at the 3rd survey 10 y later. Odds ratios (with 95% confidence limits) for developing obesity between the last two surveys were estimated by logistic regression analysis, taking into account baseline and preceding changes in BMI and LTPA. A similar analysis of odds ratios for physical inactivity as outcome at the 3rd survey was conducted.

RESULTS

Compared to physical inactivity, the odds ratios of development of obesity among women with medium and high level of activity were 0.81 (0.53, 1.25) and 1.16 (0.73, 1.84), respectively, and among men, the odds ratios were 1.28 (0.71, 2.33) and 1.65 (0.91, 2.99), respectively. Compared to median BMI, the odds ratio of later physical inactivity among women with high BMI was 1.91 (1.39, 2.61), and among men the odds ratio was 1.50 (1.01, 2.22). The associations were not confounded or modified by age, pre-existing diseases, smoking, alcohol intake, educational level, occupational physical activity or by familial predisposition to obesity.

CONCLUSION

This study did not support that physical inactivity as reported in the freely living adult population in the long term is associated with the development of obesity, but the study indicates that obesity may lead to physical inactivity.

It is never too late: change in physical activity fosters change in cardiovascular risk factors in middle-aged women

The purpose of the study was to determine the effect of physical activity, particularly change in physical activity over time, on cardiovascular risk factors in women. The 520 women in this analysis are part of an ongoing epidemiologic investigation of the effects of menopause on risk for cardiovascular disease; the investigation spans almost 20 years. The findings show that on average, physically active women have healthier risk factor profiles over time, and that as women change their activity level, their risk factor profiles change as well. Thus, for middle-aged women going through the menopausal transition, it is never too late to reduce their cardiovascular risk by increasing their activity level.

The role of physical activity in prevention and treatment of body weight gain in adults

Overweight and obesity are increasing in prevalence, and this has resulted in a significant public health burden. Therefore, it is important to identify interventions that prevent weight gain and prevent weight regain after weight loss. Energy expended in physical activity has the potential to affect energy balance, and this can potentially affect body weight regulation. There is some evidence that physical activity can minimize weight gain, and it appears that needs to be moderate to vigorous in intensity to significantly affect body weight. Moreover, it appears that improvements in fitness are associated with reductions in risk of weight gain. Physical activity also is associated with improved maintenance of weight loss. Although it appears that interventions targeting physical activity are necessary to affect weight gain and improve long-term weight loss, the impact of these interventions on other components of energy balance should be examined. In addition, although minimal public health recommendations can significantly affect health outcomes, additional research is needed to identify the optimal dose of physical activity to prevent weight gain and improve long-term weight loss.

Non-exercise activity thermogenesis (NEAT)

Non-exercise activity thermogenesis (NEAT) is the energy expended for everything we do that is not sleeping, eating or sports-like exercise. It ranges from the energy expended walking to work, typing, performing yard work, undertaking agricultural tasks and fidgeting. Even trivial physical activities increase metabolic rate substantially and it is the cumulative impact of a multitude of exothermic actions that culminate in an individual's daily NEAT. It is, therefore, not surprising that NEAT explains a vast majority of an individual's non-resting energy needs. Epidemiological studies highlight the importance of culture in promoting and quashing NEAT. Agricultural and manual workers have high NEAT, whereas wealth and industrialization appear to decrease NEAT. Physiological studies demonstrate, intriguingly, that NEAT is modulated with changes in energy balance; NEAT increases with overfeeding and decreases with underfeeding. Thus, NEAT could be a critical component in how we maintain our body weight and/or develop obesity or lose weight. The mechanism that regulates NEAT is unknown. However, hypothalamic factors have been identified that specifically and directly increase NEAT in animals. By understanding how NEAT is regulated we may come to appreciate that spontaneous physical activity is not spontaneous at all but carefully programmed.

Physical activity and its impact on health outcomes. Paper 2: Prevention of unhealthy weight gain and obesity by physical activity: an analysis of the evidence

The current guidelines for physical activity are based on the prevention of cardiovascular disease. In this article the magnitude and type of physical activity required to prevent unhealthy weight gain are assessed. Five categories of analyses are considered, ranging from the most rigorous analyses (based on D2O18 measures of energy expenditure) to socio-ecological associations. To standardize the approach, published work on the extent of exercise was expressed as a physical activity level (PAL), i.e. the ratio of total expenditure to the measured or estimated basal metabolic rate. D2O18, direct monitoring and measurements of activity patterns and detailed prospective studies of substantial population groups all suggest that a PAL of > or = 1.8 is required to limit the proportion of overweight and obese adult men. Data on women are more difficult to interpret because women are less active and the relationship with physical activity is usually less clear. Post-obese women with a PAL of >1.75 do not regain weight and other data are consistent with the need for a PAL of > or = 1.8. The analyses in both sexes are based predominantly on adults living in a Western society with the ready availability of energy-dense foods. Vigorous activity is more clearly linked to weight stability, allows a higher intensity of exercise for general activities and shortens the time needed for achieving a PAL of 1.8. This activity level is equivalent to an additional 60-90 min of brisk walking in adults who normally undertake only modest exercise. These demands are greater than the current suggested levels for cardiovascular benefit and imply the need for different environmental policies, rather than health education policies, if societies are to become generally more active and avoid unhealthy weight gain.

Physical activity, aerobic fitness, and seven-year changes in adiposity in the Canadian population

Associations among baseline physical activity, aerobic fitness, changes in physical activity, and 7-y changes in adiposity were determined. The sample consisted of 602 males and 644 females, aged 20-69 y, from the 1981 Canada Fitness Survey and the 1988 Campbell's Survey. Questionnaire-derived measures of physical activity level consisted of activity energy expenditure (AEE) and time spent on physical activity. Participants were grouped into physical activity level categories by AEE and physical activity intensity (based on MET values), and physical activity level changes were determined from movement between tertiles of AEE from baseline to follow-up. Aerobic fitness levels at baseline were determined using the Canadian Aerobic Fitness Test. Changes in body mass, the sum of five skinfolds (SF5), and waist circumference (WC) were used as indicators of adiposity change. ANCOVA and multiple regression analyses indicated that neither baseline physical activity levels, intensity, physical activity change categories, nor aerobic fitness levels were significant predictors of changes in adiposity. In conclusion, physical activity was not predictive of 7-y changes in indicators of adiposity in this sample.

Longitudinal changes in body composition in older men and women: role of body weight change and physical activity

BACKGROUND

Estimates of body-composition change in older adults are mostly derived from cross-sectional data.

OBJECTIVE

We examined the natural longitudinal patterns of change in fat-free mass (FFM) and fat mass (FM) in older adults and explored the effect of physical activity, weight change, and age on these changes.

DESIGN

The body composition measured by hydrodensitometry and the level of sports and recreational activity (SRA) of 53 men and 78 women with a mean (+/-SD) initial age of 60.7 +/- 7.8 y were examined on 2 occasions separated by a mean (+/-SD) time of 9.4 +/- 1.4 y.

RESULTS

FFM decreased in men (2.0% per decade) but not in women, whereas FM increased similarly in both sexes (7.5% per decade). Levels of SRA decreased more in men than in women over the follow-up period. Baseline age and level of SRA were inversely and independently associated with changes in FM in women only. Neither age nor level of SRA was associated with changes in FFM in men or women. Weight-stable subjects lost FFM. FFM accounted for 19% of body weight in those who gained weight, even in the presence of decreased levels of SRA. Loss of FFM (33% of body weight) was pronounced in those who lost weight, despite median SRA levels >4184 kJ/wk.

CONCLUSIONS

On average, FM increased; however, the increase in women was attenuated with advancing age. The decrease in FFM over the follow-up period was small and masked the wide interindividual variation that was dependent on the magnitude of weight change. The contribution of weight stability, modest weight gains, or lifestyle changes that include regular resistance exercise in attenuating lean-tissue loss with age should be explored.

Update on cardiovascular disease in post-menopausal women

Cardiovascular disease (CVD), and in particular coronary artery heart disease (CAHD), is the leading cause of morbidity and mortality in women. Until recently, most of our knowledge about the pathophysiology of CVD in women - and, subsequently, management guidelines - were based on studies conducted mostly in men. While similar mechanisms operate to induce CVD in women and men, gender-related differences exist in the anatomy and physiology of the myocardium, and sex hormones modify the course of disease in women. Women, more than men, have their initial manifestation of CAHD as angina pectoris; are likely to be referred for diagnostic tests at a more advanced stage of disease, and are less likely than men to have corrective invasive procedures. The overall morbidity and mortality following the initial ischaemic heart event is worse in women, and the case fatality rate is greater in women than in men. Also, the relative impact of impaired vasoreactivity of the coronary artery, increased viscosity of the blood and dysregulation of automaticity and arrhythmia, is greater in women than in men. The most effective means of decreasing the impact of CVD on women's health is by an active approach from childhood to proper principles of healthcare in order to modify the contribution of specific risk factors. The latter include obesity, abnormal plasma lipid profile, hypertension, diabetes mellitus, cigarette smoking, sedentary lifestyle, increased blood viscosity, augmented platelet aggregability, stress and autonomic imbalance. The use of lipid-lowering drugs has not been adequately studied in women but reports from studies conducted mostly in men do predict an advantage also to women. Oestrogen deficiency after spontaneous or medically induced menopause is an important risk factor for CVD and CAHD. Observational and mechanistic data suggest a role for oestrogen replacement after menopause for primary, and possibly secondary, prevention of CVD. However, two recent prospective trials suggest that treatment de novo with hormone replacement of older post-menopausal women after an acute coronary event may not confer cardiovascular protection and may increase the risk of thromboembolic disease. Results of ongoing long-term studies may determine the beneficial role of hormone replacement versus potential risks involved with this treatment.

Recent weight changes and weight cycling as predictors of subsequent two year weight change in a middle-aged cohort

OBJECTIVE

To evaluate the influence of recent weight changes (weight gain, loss and cycling) on subsequent weight changes.

DESIGN

Prospective cohort study with 2 y of follow-up. Data analysis with a polytomous logistic regression model.

SUBJECTS

A total of 18 001 non-smoking subjects, 6689 men and 11 312 women, from the general population.

MEASUREMENTS

Body height and weight measurements and interview data on lifestyle habits and medical history at baseline. For follow-up, self-administered questionnaires for assessment of body weight and incident diseases.

RESULTS

Recent changes in body weight, that is weight gain, weight loss and weight cycling, were significant predictors of subsequent weight changes in both men and women after controlling for age, baseline BMI and several lifestyle and behavioural characteristics as potential confounding factors. Weight cycling before baseline was the strongest predictor of subsequent large weight gain (> or =2 kg) with an odds ratio (OR) of 4.84 (95% confidence interval (CI) 3.34-7.02) in men. In women, prior weight loss was the strongest predictor of subsequent large weight gain (OR 4.77; 95% CI 3.63-6.03), followed by weight cycling (OR 3.02; 95% CI 2.15-4.25).

CONCLUSION

These data indicate the need for thorough weight history assessment to identify those who are most likely to gain weight. Effective weight control before the development of obesity or after intentional weight loss due to obesity should be a primary goal in the management of obesity.

Recruitment and cardiovascular risk characteristics of African American and Caucasian midlife women

This article describes the use of multiple strategies to recruit women, particularly African American women, into a home-based, moderate-intensity walking intervention and compares African American to Caucasian midlife women on cardiovascular risk characteristics at entry into the program. One hundred seventy-three women aged 45 to 65 years were recruited using a variety of strategies. Baseline findings showed that, on average, the women in the program had modifiable cardiovascular risk factors with proportionately more African American women than Caucasian women having hypertension and low physical fitness. The findings also illustrate the importance of using multiple recruitment strategies to encourage midlife African American and Caucasian women to participate in intervention trials.

Influence of leisure time physical activity and television watching on atherosclerosis risk factors in the NHLBI Family Heart Study

Physical activity favorably influences atherosclerosis risk factors but only a few studies in adults considered the time watching television (TV) as a measure of physical inactivity. We therefore determined in a population-based sample of 1778 subjects from the NHLBI Family Heart Study (FHS) whether leisure time physical activity and TV watching have independent or interactive associations with cardiovascular disease risk factors and carotid artery intima-media wall thickness (IMT). Subjects were free from diabetes mellitus and clinically-ascertained coronary artery disease and did not take lipid-lowering or antihypertensive drugs. Only 0.7 and 1.3% of the variance in leisure time physical activity in women and men, respectively, was explained by the amount of TV watching. Leisure time physical activity had a clearly favorable, and TV watching an unfavorable association with anthropometric measurements (BMI (body mass index), waist girth, waist-hip ratio, subscapular and triceps skinfold thickness). The odds ratio (95% CI) of being overweight was 0.41 (0.28-0.62) in women and 0.69 (0.46-1.04) in men in the highest quartile of leisure time physical activity compared to the lowest quartile. The odds ratio increased for increasing quartiles of TV watching to 2.12 (1.45-3.10) in women and 1.61 (1.07-2.43) in men. Watching TV only 1 h per day in women with a BMI of 30 kg/m2 and doing about 75 min of moderate exercise per week was associated with a BMI 1.8 kg/m2 lower than in women watching TV 3 h per day and doing the same amount of exercise. Those with twice the amount of moderate exercise and watching TV 1 h per day had a BMI 0.45 kg/m2 lower. Furthermore, leisure time physical activity was negatively associated with concentrations of triglycerides and positively with HDL cholesterol in both genders. TV watching was significantly positively associated with triglycerides and slightly negatively with HDL cholesterol in men. The observed associations of leisure time physical activity and TV watching with atherosclerosis risk factors were independent from each other. Finally, we analyzed the relation between leisure time physical activity, TV watching and the degree of IMT of the carotid arteries. Neither of these two measures was significantly associated with IMT. In summary, TV watching, in addition to leisure time physical activity, shows an independent association with obesity-related anthropometric measurements, HDL and triglycerides. Decreasing the amount of TV watching might be effective as a first step in reducing atherosclerosis risk factors, especially overweight.

Physical activity and body weight: associations over ten years in the CARDIA study. Coronary Artery Risk Development in Young Adults

BACKGROUND

Hypothesis 1--sustained changes in physical activity are inversely related to changes in body weight. Hypothesis 2-those who attenuate weight gain because of a temporary increase in physical activity (PA) may maintain a lower body weight over time.

METHODS

Data were from the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a cohort of black and white men and women, aged 18-30y at baseline, who attended up to five examinations over a 10y period (n=5,115 at baseline). Longitudinal associations between physical activity and body weight changes were assessed, adjusting for secular trend, age, clinic site, education, smoking, alcohol intake, parity, percentage energy intake from fat, and changes in these variables over time. For hypothesis 1, concurrent associations of physical activity and body weight changes were examined. For hypothesis 2, we explored whether weight gain attenuation associated with increased PA during the initial 2-3 y of follow-up was sustained over 5 y. The study 2 analyses were conducted with three separate 5y intervals: baseline to year 5 (n= 3,641), years 2-7 (n= 3,160), and years 5-10 (n= 2,617).

RESULTS

Hypothesis 1 -change in physical activity was inversely associated with change in body weight within all four race and sex sub-groups (P<0.005). The predicted weight change associated with change in physical activity was four to five times larger in participants who were overweight compared with those who were not were overweight at baseline. Hypothesis 2-an increase in physical activity during 2-3 y of follow-up was associated with an attenuation of weight gain that was sustained through 5y of follow-up whether or not the physical activity increase was maintained during the later years. This finding persisted whether the starting point for the 5y follow-up was year 2, year 5 or baseline (women only). Comparing participants who increased physical activity with those who decreased physical activity in the first 2-3 y of follow-up (eg by at least 2 h per week of stationary cycling for at least 6 months per year), the mean 5y weight gain attenuation ranged from 0.8 to 2.8 kg.

CONCLUSIONS

The results of these analyses support the need for public health messages for promoting increased physical activity for weight maintenance and attenuation of age-related weight gain, especially for higher weight sub-populations.

Does physical activity prevent weight gain--a systematic review

This paper is a systematic review of research data on associations between physical activity and weight gain, with or without prior weight reduction. The selected studies were restricted to Caucasian (white) adults. Most studies with data on physical activity collected at follow-up, found an inverse association between physical activity and long-term weight gain. This finding was present in studies both with and without prior weight reduction. Prospective studies with physical activity measured at baseline, and randomized weight reduction interventions, gave inconsistent results regarding the effects of increased physical activity on weight change. The weighted mean weight regain in randomized studies with or without exercise training was 0.28 and 0.33 kg/month, respectively. Based on observational studies, it seemed that an actual increase in energy expenditure of physical activity of approximately 6300-8400 kJ/week (1500-2000 kcal/week) is associated with improved weight maintenance. This is more than was prescribed in most randomized trials, and certainly more than the participants actually achieved. Adherence to a prescribed exercise programme remains a big challenge. Before new methods to improve exercise adherence are found, the role of prescribed physical activity in prevention of weight gain remains modest.

Predictors of weight gain in the Pound of Prevention study

OBJECTIVES

This study examined cross-sectional and prospective relationships between macronutrient intake, behaviors intended to limit fat intake, physical activity and body weight.

DESIGN

The overall goal was to identify diet and exercise behaviors that predict and/or accompany weight gain or loss over time. Specific questions addressed included: (a) are habitual levels of diet or exercise predictive of weight change; (b) are habitual diet and exercise levels associated cross-sectionally with body weight; and (c) are changes in diet and exercise associated with changes in body weight over time?

PARTICIPANTS

Subjects were a sample of community volunteers (n=826 women, n=218 men) taking part in a weight gain prevention project over a 3-year period.

MEASURES

Body weight was measured at baseline and annually over the study period. Self-report measures of diet and exercise behavior were also measured annually.

RESULTS

Among both men and women, the most consistent results were the positive association between dietary fat intake and weight gain and an inverse association between frequency of physical activity and weight gain. Individuals who weighed more both ate more and exercised less than those who weighed less. Individuals who increased their physical activity level and decreased their food intake over time were protected from weight gain compared to those who did not. Frequency of high-intensity physical activity was particularly important for both men and women. Additionally, women who consistently engaged in higher levels of moderate physical activity gained weight at a slower rate compared to women who were less active.

CONCLUSIONS

Overall results indicated that both cross-sectionally and prospectively, the determinants of weight and weight change are multifactorial. Attention to exercise, fat intake and total energy intake all appear important for successful long term control of body weight.

Body weight in bulimia nervosa

OBJECTIVES

The objectives of this study were to determine: 1) factors associated with body mass index (BMI) in women with bulimia nervosa prior to treatment; 2) changes in BMI during cognitive behavioral therapy (CBT) for bulimia nervosa; and 3) predictors of weight change during CBT treatment.

METHODS

Participants were 94 women with DSM-III-R bulimia nervosa enrolled in a randomized clinical trial of CBT. Eating disorder symptomatology, past and current psychopathology, and BMI were measured prior to treatment and after twelve weeks of treatment.

RESULTS

A significantly lower BMI prior to treatment was independently associated with a history of anorexia nervosa, substance use, cigarette smoking, and a high frequency of vomiting. Reductions in binge eating, purging, and food restriction after treatment did not result in significant changes in BMI. Increasing age, higher maximum lifetime body weight, and a high frequency of binge eating at baseline predicted weight gain during treatment. Weight loss during treatment was predicted by a high frequency of vomiting, and elevated levels of body dissatisfaction prior to treatment.

DISCUSSION

Patients hesitant to engage in treatment for fear of weight gain upon cessation of their bulimic behaviors should be reassured that CBT is not usually accompanied by substantial weight gain. Identification of women at risk of significant weight gain or loss during CBT may enable therapists to focus on its aspects that help to prevent excessive body weight changes.