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Background: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass., Objectives: A study is presented of the association between FFM and physical activity in relation to age., Methods: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution., Results: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males < 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants < 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively., Conclusions: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Background: We investigated the effect of equivalent weight loss, by a hypocaloric diet or mainly exercise, on inflammatory markers and adipokines in overweight postmenopausal women., Methods: Women were randomized to a diet (n = 97), mainly exercise (n = 98), or control group (n = 48). Goal of both interventions was to lose 5 to 6 kg bodyweight by a hypocaloric diet or an exercise program (4 hours/week) combined with a small caloric intake restriction. Outcomes after 16 weeks included serum high-sensitive C-reactive protein (hsCRP), IL6, adiponectin, and leptin., Results: Both intervention groups achieved the target weight loss. Controls remained weight stable. Compared with control, hsCRP decreased with mainly exercise [treatment effect ratio (TER) = 0.64] and borderline statistically significant with diet (TER = 0.77). There was a suggestively larger effect of exercise, directly compared with diet (TER = 0.83). Leptin decreased with both interventions: mainly exercise (TER = 0.55) and diet (TER = 0.59), versus control. Effects attenuated and lost significance after adjusting for change in body fat percentage, and to a lesser extent when adjusting for fitness. No effects were seen on IL6 and adiponectin., Conclusions: A 16-week randomized intervention inducing comparable weight loss by a hypocaloric diet or mainly exercise, resulted in favorable effects on serum hsCRP and leptin. We found a possible more beneficial effect on hsCRP with mainly exercise versus diet. These effects of exercise were established by changes in body fat percentage and physical fitness., Impact: A modest amount of weight loss in postmenopausal women reduces hsCRP and leptin levels which might be associated with a lower breast cancer risk. Cancer Epidemiol Biomarkers Prev; 25(5); 799-806. ©2016 AACR., (©2016 American Association for Cancer Research.)

Introduction: Physical inactivity and overweight are risk factors for postmenopausal breast cancer. The effect of physical activity may be partially mediated by concordant weight loss. We studied the effect on serum sex hormones, which are known to be associated with postmenopausal breast cancer risk, that is attributable to exercise by comparing randomly obtained equivalent weight loss by following a hypocaloric diet only or mainly by exercise., Methods: Overweight, insufficiently active women were randomised to a diet (N = 97), mainly exercise (N = 98) or control group (N = 48). The goal of both interventions was to achieve 5-6 kg of weight loss by following a calorie-restricted diet or an intensive exercise programme combined with only a small caloric restriction. Primary outcomes after 16 weeks were serum sex hormones and sex hormone-binding globulin (SHBG). Body fat and lean mass were measured by dual-energy X-ray absorptiometry., Results: Both the diet (-4.9 kg) and mainly exercise (-5.5 kg) groups achieved the target weight loss. Loss of body fat was significantly greater with exercise versus diet (difference -1.4 kg, P < 0.001). In the mainly exercise arm, the reduction in free testosterone was statistically significantly greater than that of the diet arm (treatment effect ratio [TER] 0.92, P = 0.043), and the results were suggestive of a difference for androstenedione (TER 0.90, P = 0.064) and SHBG (TER 1.05, P = 0.070). Compared with the control arm, beneficial effects were seen with both interventions, diet and mainly exercise, respectively, on oestradiol (TER 0.86, P = 0.025; TER 0.83, P = 0.007), free oestradiol (TER 0.80, P = 0.002; TER 0.77, P < 0.001), SHBG (TER 1.14; TER 1.21, both P < 0.001) and free testosterone (TER 0.91, P = 0.069; TER = 0.84, P = 0.001). After adjustment for changes in body fat, intervention effects attenuated or disappeared., Conclusions: Weight loss with both interventions resulted in favourable effects on serum sex hormones, which have been shown to be associated with a decrease in postmenopausal breast cancer risk. Weight loss induced mainly by exercise additionally resulted in maintenance of lean mass, greater fitness, greater fat loss and a larger effect on (some) sex hormones. The greater fat loss likely explains the observed larger effects on sex hormones., Trial Registration: ClinicalTrials.gov identifier: NCT01511276 . Registered on 12 January 2012.

Introduction: This study investigates the effect of a modest weight loss either by a calorie restricted diet or mainly by increased physical exercise on health related quality of life (HRQoL) in overweight-to-obese and inactive postmenopausal women. We hypothesize that HRQoL improves with weight loss, and that exercise-induced weight loss is more effective for this than diet-induced weight loss., Methods: The SHAPE-2 trial was primarily designed to evaluate any additional effect of weight loss by exercise compared with a comparable amount of weight loss by diet on biomarkers relevant for breast cancer risk. In the present analysis we focus on HRQoL. We randomly assigned 243 eligible women to a diet (n = 97), exercise (n = 98), or control group (n = 48). Both interventions aimed for 5-6 kg weight loss. HRQoL was measured at baseline and after 16 weeks by the SF-36 questionnaire., Results: Data of 214 women were available for analysis. Weight loss was 4.9 kg (6.1%) and 5.5 kg (6.9%) with diet and exercise, respectively. Scores of the SF-36 domain 'health change' increased significantly by 8.8 points (95% CI 1.6;16.1) with diet, and by 20.5 points (95% CI 13.2;27.7) with exercise when compared with control. Direct comparison of diet and exercise showed a statistically significantly stronger improvement with exercise. Both intervention groups showed a tendency towards improvements in most other domains, which were more pronounced in the exercise group, but not statistically different from control or each other., Conclusion: In a randomized trial in overweight-to-obese and inactive postmenopausal women a comparable 6%-7% weight loss was achieved by diet-only or mainly by exercise and showed improvements in physical and mental HRQoL domains, but results were not statistically significant in either the diet or exercise group. However, a modest weight loss does lead to a positive change in self-perceived health status. This effect was significantly larger with exercise-induced weight loss than with comparable diet-induced weight loss., Trial Registration: ClinicalTrials.gov NCT01511276.

Background: An inactive lifestyle is a risk factor for several types of cancer. A proposed pathway through which exercise influences cancer risk is via insulin. We aim to investigate the effect of a one-year exercise intervention on insulin sensitivity, and the role of body fat in this association, in healthy, normal to overweight/obese, postmenopausal women., Methods: In the Sex Hormones And Physical Exercise (SHAPE) study, 189 healthy, inactive and postmenopausal women [ages, 50-69 years; body mass index (BMI), 22-40 kg/m(2)] were randomly assigned to a one-year aerobic and strength exercise intervention (150 min/wk), or a control group. Between-group differences in fasting insulin, glucose, and homeostatic model assessment of insulin resistance (HOMA2) over time were estimated using linear mixed models., Results: Follow-up measurements of insulin sensitivity were available for 181 (95.8%) and 182 (96.3%) women at 4 and 12 months, respectively. The intention-to-treat analysis showed no significant differences between the two study groups [treatment effect ratio of the exercise group vs. control (β; 95% confidence interval): insulin, β, 1.07 (0.96-1.19); glucose, β, 1.01 (0.99-1.02); and HOMA2, β, 1.07 (0.96-1.20)]. Similar results were found in a per protocol analysis in compliant women, and in a subgroup of women who lost >2% body fat [measured by dual-energy X-ray absorptiometry (DEXA)]., Conclusions: Participation in a one-year aerobic and strength exercise intervention program did not result in changes in insulin sensitivity in healthy postmenopausal and inactive women., Impact: Our findings suggest that 150 min/wk of exercise, as recommended by current guidelines, is not enough to achieve improvements in insulin sensitivity and subsequent cancer risk, in healthy postmenopausal women., (©2014 American Association for Cancer Research.)

Background: Physical inactivity and overweight are two known risk factors for postmenopausal breast cancer. Former exercise intervention studies showed that physical activity influences sex hormone levels, known to be related to postmenopausal breast cancer, mainly when concordant loss of body weight was achieved. The question remains whether there is an additional beneficial effect of physical activity when weight loss is reached., Design: The SHAPE-2 study is a three-armed, multicentre trial. 243 sedentary, postmenopausal women who are overweight or obese (BMI 25-35 kg/m2) are enrolled. After a 4-6 week run-in period, wherein a baseline diet is prescribed, women are randomly allocated to (1) a diet group, (2) an exercise group or (3) a control group. The aim of both intervention groups is to lose an amount of 5-6 kg body weight in 10-14 weeks. The diet group follows an energy restricted diet and maintains the habitual physical activity level. The exercise group participates in a 16-week endurance and strength training programme of 4 hours per week. Furthermore, they are prescribed a moderate caloric restriction. The control group is asked to maintain body weight and continue the run-in baseline diet., Discussion: This study will give insight in the potential attributable effect of physical activity on breast cancer risk biomarkers and whether this effect is mediated by changes in body composition, in postmenopausal women. Eventually this may lead to the design of specific lifestyle guidelines for prevention of breast cancer., Trial Registration: The SHAPE-2 study is registered in the register of clinicaltrials.gov, Identifier: NCT01511276.

Objectives: The aim of this study is (1) to gain insight into current multi-sector policy initiatives that contribute to activity-friendly environments for children in four Dutch municipalities, (2) to investigate the role of multi-sector collaboration in multi-sector policy action and (3) to gain insight into critical facilitators and possible challenges for multi-sector policy action aimed at creating activity-friendly environments for children., Methods: A policy analysis was conducted in four Dutch municipalities by means of semi-structured interviews with 25 policy officers from different policy sectors. Interviews were transcribed ad verbatim and analyzed using qualitative data coding software., Results: Each policy sector carried out policy measures related to (the environmental determinants of) physical activity among children, but most respondents were not aware of the potential effectiveness of their policy measures regarding this topic. In two municipalities structural collaboration between policy sectors was present, but the number of sectors involved was limited. Awareness and support among all policy sectors, a stimulating political environment, and knowing each other and being informed about other sectors' policies were mentioned as facilitators for multi-sector policy action. The main challenge for multi-sector policy action was lack of time and resources., Conclusions: This study shows that multi-sector policy action aimed at activity-friendly environments could be stimulated by raising awareness and defining problem ownership, enhancing multi-sector collaboration and paying attention to facilitators and challenges., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background: Physical inactivity in children is a major health problem in The Netherlands as well as in many other Western countries. In addition to health promotion among parents and children, creating "active" neighbourhoods can contribute to the solution of this health problem. However, changing environmental characteristics is often the responsibility of policy sectors outside the Public Health domain. Therefore this project identifies and evaluates the possibilities of multi-sector policy measures to stimulate physical activity in children., Methods and Design: The project consists of quantitative as well as qualitative research methods and is conducted in four medium sized Dutch cities. To identify perceived environmental determinants of physical activity in children, a large scale health survey was conducted at 42 primary schools. Written questionnaires including topics on the children's physical activity behaviour (i.e. sports participation, outdoor play, active commuting, television watching and computer usage) and physical and social environmental characteristics were completed by 6,601 parents of children aged 3-13 years old and 3449 children aged 9-13 years old. In addition, 33 neighbourhood audits (systematic observations) were conducted to assess objective neighbourhood characteristics. Furthermore, a policy analysis was conducted in the four participating municipalities to provide an overview of the current local policy measures directed at stimulation of physical activity in children. Policy plans of six different policy sectors (Public Health, Sports, Education & Youth, Spatial Planning, Traffic & Transport, and Safety) were screened for their content on physical activity in children. In addition, semi-structured interviews were conducted with policy makers of each of these sectors to identify critical success factors in the development and realization of multi-sector policy plans aimed at stimulating physical activity in children. The results of all these research activities will be discussed with local policy makers during interactive workshop sessions in order to identify clear cut multi-sector policy measures that stimulate physical activity in children., Discussion: This paper describes the study design of a project that focuses on multi-sector policy measures that stimulate physical activity in children. Next to extensive research into the environmental determinants of physical activity in children, much emphasis is placed on the translation of the research outcomes into concrete and feasible policy plans.

Purpose: To examine the effects of a 1-year exercise intervention on sex hormone levels in postmenopausal women and whether any effects are mediated by changes in body fat composition., Methods: We randomly assigned 189 sedentary postmenopausal women (age 50 to 69 years, body mass index of 22 to 40 kg/m(2)) to an exercise intervention (n = 96) or a control group (n = 93). The intervention combined aerobic and strength training and comprised supervised group sessions and home-based exercises (a total of 2.5 h/wk). Between-group differences in sex hormone levels (at baseline and 4 and 12 months) were examined with generalized estimating equations., Results: In total, 183 women (97%) completed the study. Overall, the exercise intervention did not result in favorable effects on sex hormone levels. Among women who lost more than 2% body fat, declines in all estrogens were not significantly different between exercisers and controls. Androgen levels decreased significantly in the exercise group who lost body fat compared with their peers in the control group. Furthermore, this study confirmed that fat loss was significantly associated with declines in postmenopausal estrogen levels. Although not significant, a similar trend was observed for the androgens., Conclusion: This study confirms that fat loss is associated with changes in postmenopausal sex hormone levels and suggests that exercise may be effective in inducing favorable changes in these hormones.

Background: Accurate measures of physical activity are highly needed. We evaluated the test-retest reliability and construct validity of the self-report Activity Questionnaire for Adults and Adolescents (AQuAA). The AQuAA is a commonly used questionnaire in Dutch youth., Methods: In the test-retest reliability study, 53 adolescents and 58 adults completed the AQuAA twice, with an interval of two weeks. In the validity study, 33 adolescents and 47 adults wore an accelerometer (Actigraph) during two weeks, and subsequently completed the AQuAA., Results: In adolescents the test-retest reliability was fair to moderate (intraclass correlations (ICCs) ranging from 0.30 to 0.59). In adults the test-retest reliability was fair to moderate for the time spent on sedentary, light and moderate intensity activities (ICCs ranging from 0.49 to 0.60), but poor for time spent on vigorous activities (ICC = -0.005). The correlations between the AQuAA and Actigraph were low and nonsignificant. Compared with the Actigraph, time spent on all physical activities was significantly higher according to the questionnaire (except for light intensity activities in adolescents), while time spent on sedentary behaviours was significantly lower., Conclusion: Reliability of the AQuAA is fair to moderate. The validity of the AQuAA compared to an accelerometer is poor. Both adolescents and adults underestimate the time spent on sedentary behaviours and overestimate the time spent on physical activities.

Background: Inactive people are often not aware of the fact that they are insufficiently active. Providing insight into their actual physical activity (PA) levels may raise awareness and could, in combination with tailored PA advice, stimulate a physically active lifestyle., Objective: This study evaluated the feasibility and effectiveness of a 3-month intervention in which Dutch office workers were provided with a personal activity monitor (PAM) coupled to simple and concise Web-based tailored PA advice (PAM COACH)., Method: Participants were randomly assigned to the 3-month PAM intervention (n = 51) or received a single written information brochure with brief general PA recommendations (n = 51). Study outcome measures were changes in PA (recall of minutes per week spent on PA, as measured by the Activity Questionnaire for Adolescents and Adults), determinants of PA, aerobic fitness, and body composition. Follow-up measurements were performed immediately after the 3-month intervention and at 8-months, 5 months after the end of the 3-month intervention period., Results: A total of 102 workers, 23 to 39 years old, completed the baseline measurement at the worksite. 48 completed the 3-month follow up and 38 the 8-month follow-up in the intervention group, 50 completed the 3-month follow up and 42 the 8-month follow up in the control group. 35 out of 48 (73%) participants in the PAM intervention group reported wearing the PAM regularly, and the PAM COACH was used almost once a week; 24 out of 46 (52%) PAM users set a personal goal, and 33 (72%) entered their favorite activities on the website. Main reasons for not using these items were lack of interest or not being able to find the item on the website. The majority of PAM users (34 out of 46, 74%) read the advice, of whom 14 (39%) found it unappealing. After the 3-month intervention, no significant intervention effect was observed (adjusted difference in min/week) for sedentary behavior (beta = 10, 95% CI = -435 to 455), light-intensity PA (beta = -129, 95% CI = -337 to 79), moderate-intensity PA (beta = -13, 95% CI = -89 to 63), vigorous-intensity PA (beta= -6, 95% CI = -75 to 62), and moderate- to vigorous-intensity PA (beta = -23, 95% CI = -121 to 76). No significant intervention effect was observed in the PA outcomes at the 8-month follow-up. For the determinants of PA, aerobic fitness, and body composition, no statistically significant intervention effect was observed in the total study population immediately after the 3-month intervention or the 8-month follow-up., Conclusions: The intervention appeared to be easily applicable to real-life settings. The intervention was ineffective in improving PA behavior or its determinants in healthy office workers. More attention should have been given to the quality and appropriateness of the tailored advice., Trial Registration: International Standard Randomized Controlled Trial Number (ISRCTN): 93896459; http://www.controlled-trials.com/ISRCTN93896459/ (Archived by WebCite at http://www.webcitation.org/5iR3mf7ex).

Unlabelled: The aim of this study was to investigate the effect of a 12-month moderate-to-vigorous exercise program combining aerobic and muscle strength training on body composition among sedentary, postmenopausal women., Methods: A randomized controlled trial was conducted. A total of 189 sedentary postmenopausal women (age 50-69 y, body mass index 22-40 kg/m2) were randomly assigned to an exercise (n = 96) or a control group (n = 93). Study parameters measured at baseline, 4 months, and 12 months were as follows: body weight and body height (body mass index), waist and hip circumference (body fat distribution), and dual-energy x-ray absorptiometry (total body fat and lean mass). Differences in changes in study parameters between exercise and control group were examined with generalized estimating equations analysis., Results: The exercise program did not result in significant effects on weight, body mass index, and hip circumference. The exercise group experienced a statistically significant greater loss in total body fat, both absolute (-0.33 kg) (borderline) as in a percentage (-0.43%) compared with the control group. In addition, lean mass increased significantly (+0.31 kg), whereas waist circumference (-0.57 cm) decreased significantly compared with the control group., Conclusions: We conclude that a 12-month exercise program combining aerobic and muscle strength training did not affect weight but positively influenced body composition of postmenopausal women. Affecting body fat distribution and waist circumference may have important health implications because it is an independent risk factor in obese but also in nonobese people. Therefore, this study gives further credence to efforts of public health and general practitioners aiming to increase physical activity levels of postmenopausal women.

Background: Physical activity has been associated with a decreased risk for breast cancer. The biological mechanism(s) underlying the association between physical activity and breast cancer is not clear. Most prominent hypothesis is that physical activity may protect against breast cancer through reduced lifetime exposure to endogenous hormones either direct, or indirect by preventing overweight and abdominal adiposity. In order to get more insight in the causal pathway between physical activity and breast cancer risk, we designed the Sex Hormones and Physical Exercise (SHAPE) study. Purpose of SHAPE study is to examine the effects of a 1-year moderate-to-vigorous intensity exercise programme on endogenous hormone levels associated with breast cancer among sedentary postmenopausal women and whether the amount of total body fat or abdominal fat mediates the effects., Methods/design: In the SHAPE study, 189 sedentary postmenopausal women, aged 50-69 years, are randomly allocated to an intervention or a control group. The intervention consists of an 1-year moderate-to-vigorous intensity aerobic and strength training exercise programme. Participants allocated to the control group are requested to retain their habitual exercise pattern. Primary study parameters measured at baseline, at four months and at 12 months are: serum concentrations of endogenous estrogens, endogenous androgens, sex hormone binding globuline and insuline. Other study parameters include: amount of total and abdominal fat, weight, BMI, body fat distribution, physical fitness, blood pressure and lifestyle factors., Discussion: This study will contribute to the body of evidence relating physical activity and breast cancer risk and will provide insight into possible mechanisms through which physical activity might be associated with reduced risk of breast cancer in postmenopausal women.

Purpose: To determine whether physical activity is associated with glucose tolerance in the elderly., Methods: We examined current and 5-yr change in physical activity in relation to glucose tolerance in 424 randomly selected male inhabitants of the Dutch town Zutphen, aged 69-89 yr, without known diabetes mellitus. Physical activity was assessed by a validated questionnaire designed for retired men. Glucose intolerance was assessed by an oral glucose tolerance test and defined as impaired glucose tolerance or diabetes mellitus., Results: Men with 30 min x d(-1) or more of physical activity of at least moderate intensity had a lower prevalence of glucose intolerance as compared to men without these activities (age-adjusted odds ratio 0.32; 95% CI, 0.18-0.57). Adjustment for family history of diabetes, smoking, alcohol intake, dietary factors, body mass index, and subscapular skin-fold thickness or exclusion of men with cardiovascular diseases or disabilities did not substantially change the results. With specific activities modeled simultaneously, bicycling (P for trend = 0.01) and gardening (P for trend = 0.02) were inversely associated with glucose intolerance. Men whose amount of physical activity had decreased during the past 5 yr had significantly higher age-adjusted 2-h glucose concentrations as compared with men who remained at least as active (difference 0.7 mmol x L(-1); 95% CI, 0.1-1.3)., Conclusion: These findings suggest that common types of physical activity such as bicycling and gardening may contribute to the prevention of glucose intolerance in elderly men

Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking (2H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors.

Understanding the impacts of activity on energy balance is crucial. Increasing levels of activity may bring diminishing returns in energy expenditure because of compensatory responses in non-activity energy expenditures.1-3 This suggestion has profound implications for both the evolution of metabolism and human health. It implies that a long-term increase in activity does not directly translate into an increase in total energy expenditure (TEE) because other components of TEE may decrease in response-energy compensation. We used the largest dataset compiled on adult TEE and basal energy expenditure (BEE) (n = 1,754) of people living normal lives to find that energy compensation by a typical human averages 28% due to reduced BEE; this suggests that only 72% of the extra calories we burn from additional activity translates into extra calories burned that day. Moreover, the degree of energy compensation varied considerably between people of different body compositions. This association between compensation and adiposity could be due to among-individual differences in compensation: people who compensate more may be more likely to accumulate body fat. Alternatively, the process might occur within individuals: as we get fatter, our body might compensate more strongly for the calories burned during activity, making losing fat progressively more difficult. Determining the causality of the relationship between energy compensation and adiposity will be key to improving public health strategies regarding obesity.

Total daily energy expenditure ("total expenditure") reflects daily energy needs and is a critical variable in human health and physiology, but its trajectory over the life course is poorly studied. We analyzed a large, diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 years. Total expenditure increased with fat-free mass in a power-law manner, with four distinct life stages. Fat-free mass-adjusted expenditure accelerates rapidly in neonates to ~50% above adult values at ~1 year; declines slowly to adult levels by ~20 years; remains stable in adulthood (20 to 60 years), even during pregnancy; then declines in older adults. These changes shed light on human development and aging and should help shape nutrition and health strategies across the life span.

Physical activity levels in most affluent countries are low and many people do not meet the current recommendations. Particularly for people with a low income, economic strategies seem promising to stimulate taking part in sports activities. This study investigated the importance of economic restraints for taking part in sports activities as well as perceptions of low-income people toward different pricing interventions. Methods: A qualitative study was conducted, using semistructured, individual interviews with 27 low-income men and women. The framework approach was used to analyze the transcripts of the interviews. Results: The respondents considered finances to be an important barrier for participating in sports activities, together with some individual barriers. Promising pricing strategies are a discount on the subscription to the fitness or sports club, a 1 month free trial, and free entrance to the swimming pool once a week. Conclusions: Pricing strategies may be a promising intervention to increase physical activity levels of low-income people. However, this study indicates that this should be coupled with an intervention directed at individual barriers. Some pricing strategies will be used and appreciated more by low-income people than other pricing strategies. In addition, pricing strategies should be tailored to individual needs and preferences. [ABSTRACT FROM AUTHOR]