Susana Vale

Prevalence of the Portuguese Population Attaining Sufficient Physical Activity

PURPOSE Physical activity has many health benefits, and to implement strategies, mainly in those groups with insufficient levels of practice, it is important to evaluate physical activity. The main purpose of this study was to describe the prevalence of physical activity in the Portuguese population aged 10 yr and older using accelerometry. METHODS The accelerometers were worn for four consecutive days, and a valid record was defined as at least 3 d with 10 h of wear time, including one weekend day. Considering these conditions, 4696 participants were included. RESULTS According to the recommendations of 60 min·d(-1) of physical activity, 36% of participants age 10-11 yr (boys = 51.6%, girls = 22.5%) and 4% age 16-17 yr (boys = 7.9%, girls = 1.2%) were considered sufficiently active. In adulthood, ∼70% of participants age 18-64 yr (men = 76.6%, women = 65.2%) and 35% age older than 64 yr (men = 46%, women = 29%) reached the recommendation of 30 min·d(-1) of physical activity, when counting every minute of moderate or greater intensity. Considering bouts of 10 min or more of moderate or greater intensity in participants older than 17 yr, the prevalence was 4%-6% at 18-39 yr, 7%-9% at 40-64 yr, and ∼3% in persons age 65 yr or older. CONCLUSIONS The design and implementation of strategies to promote physical activity for health among children and adolescents and older adults, particularly girls/women, should be encouraged.

Prevalence of overweight and obesity among Portuguese youth: A study in a representative sample of 10–18-year-old children and adolescents

PURPOSE The aim of this research was to report the prevalence of overweight and obesity in a representative sample of Portuguese youth. METHODS This was a school-based study performed in Portugal. A total of 22 048 children and adolescents aged 10-18 years were included in the study. The World Health Organization (WHO) and the International Obesity Task Force (IOTF) cut-offs were used to categorise overweight and obese participants. RESULTS Using IOTF cut-offs the prevalence of overweight and obesity was 17.0 and 4.6% in girls, and 17.7 and 5.8% in boys, respectively (p < 0.001 for overweight and p > 0.05 for obesity), whereas WHO cut-offs resulted in overweight and obesity prevalence scores of 23.1 and 9.6% in girls, and 20.4 and 10.3% in boys, respectively (p < 0.001 for overweight and p >0.05 for obesity). With IOTF cut-offs, a lower prevalence of obesity and overweight was observed at higher ages, in both genders. With the WHO cut-offs, a lower prevalence of obesity and overweight was observed at higher ages, in boys. In girls, the prevalence of overweight and obesity increases from 10 to 12 years of age and decreases from the age of 13 to 18 years. CONCLUSION The prevalence for overweight/obesity among Portuguese children and adolescents vary according to the cut-off points used and are also of concern requiring strategies to promote healthy weight gain among children and adolescents.

Compliance with physical activity guidelines in preschool children.

Abstract The aims of this study were (1) to document differences in physical activity (both total and moderate-to-vigorous physical activity) between the sexes on weekdays and weekend days in preschoolers, and (2) to assess compliance with recommendations for total physical activity (National Association for Sport and Physical Education guidelines) and moderate-to-vigorous physical activity on weekdays and weekend days in the same children. The sample comprised 245 preschoolers (105 girls, 140 boys) aged 3.5–6.0 years old. Physical activity was assessed using an Actigraph accelerometer. Data were analysed with specific software and activity was measured as counts per minute. An independent t-test and general linear model with repeated-measures were used to assess differences between the sexes and differences between days (weekdays and weekend days) within each sex, respectively. A chi-square test was used to determine differences between the sexes in the proportion of children complying with physical activity guidelines. In both sexes, sedentary behaviour accounted for the majority of the time on weekdays and weekend days (weekdays: 83%; weekend days: 83.9%). Boys engaged in significantly more (P < 0.05) total physical activity and moderate-to-vigorous physical activity than girls (weekdays: boys 155.4 min vs. girls 128.22 min; weekend days: boys 111.2 min vs. girls 90.5 min). On average, preschool children engaged in significantly more (P < 0.05) total physical activity and moderate-to-vigorous physical activity on weekdays than weekend days. Altogether, 74.3% and 93.5% of the children met the National Association for Sport and Physical Education guidelines and moderate-to-vigorous physical activity recommendations respectively on weekdays, whereas compliance with both recommendations was substantially less in both sexes on weekend days. The results of this study suggest that despite 83% of time during the day being spent in sedentary behaviour, most preschool children met the daily physical activity and moderate-to-vigorous physical activity recommendations on weekdays. Future research should consider the two constructs of physical activity and sedentary behaviour independently, as they might not necessarily counteract each other.

Sedentary behavior and physical activity are independently related to functional fitness in older adults.

The last decades of life have been traditionally viewed as a time of inevitable disease and frailty. Sedentary living and physical activity may influence capacity to perform activities that are needed to maintain physical independence in daily living. A total of 117 males and 195 females, aged 65-103years, were assessed for physical activity and sedentary time with accelerometers and for functional fitness with the Senior Fitness Test battery. Based on the individual scores for each fitness item, a Z-score was created. Associations between functional fitness with sedentary time and moderate-to-vigorous physical activity (MVPA) were analyzed. A negative association was found between the composite Z-score for functional fitness and the sedentary time, even adjusting for MVPA and other confounders. On the other hand, MVPA was positively associated with the composite Z-score for functional fitness, independently of the sedentary time. In conclusion elderly who spend more time in physical activity or less time in sedentary behaviors exhibit improved functional fitness and other confounders. The results reinforce the importance of promoting both the reduction of sedentary behaviors and the increase of MVPA in this age group, as it may interfere at older ages in order to preserve functional fitness and performance of daily functioning tasks.

The independent associations of sedentary behaviour and physical activity on cardiorespiratory fitness.

Background During childhood and adolescence, both physical activity (PA) and sedentary behaviour seem to influence cardiorespiratory fitness (CRF); however, the combined association of PA and sedentary behaviour remains to be understood. We analysed the combined association of objectively measured sedentary behaviour and moderate-to-vigorous intensity PA (MVPA) on CRF in Portuguese children and adolescents. Methods The sample comprised 2506 Portuguese healthy children and adolescents aged 10–18 years, from a cross-sectional school-based study (2008). PA and sedentary behaviour were assessed with accelerometry. Participants were classified as meeting current PA guidelines for youth versus not meeting, and as low versus high sedentary (according to the median value of sedentary time/day by age and gender), and then grouped as follows: Low active—high sedentary; low active—low sedentary; high active—high sedentary; high active—low sedentary. CRF was assessed with the FITNESSGRAM 20 m shuttle-run test. Binary logistic regression models were constructed to verify the relationship between high CRF and the combined influence of MVPA/sedentary behaviour, adjusting for age, gender, body mass index and accelerometer wear time. Results Participants classified as high active/low sedentary (OR=1.81; 95% CI 1.21 to 2.69), as well as those classified as low active/low sedentary (OR=1.27; 95% CI 1.01 to 1.61) were more likely to be fit, compared with those from the low-active/high-sedentary group. Conclusion MVPA and sedentary behaviour may act independently in their relation with CRF, and that MVPA levels may not overcome the deleterious influence of high-sedentary time in maximising CRF.

Prevalence of overweight, obesity, and abdominal obesity in a representative sample of Portuguese adults

This study determined the prevalence of overweight, obesity, and abdominal obesity in the Portuguese adults and examined the relationship between above mentioned prevalences and educational level. Body mass, stature, and waist circumference were measured in a representative sample of the Portuguese population aged 18–103 years (n = 9,447; 18–64 years: n = 6,908; ≥65 years: n = 2,539). Overweight and obesity corresponded to a body mass index ranging between 25–29.9 kg/m2 and ≥30 kg/m2, respectively. Abdominal obesity was assessed as >102 cm for males and >88 cm for females. After adjusting for educational level, the combined prevalences of overweight and obesity were 66.6% in males and 57.9% in females (18–64 years). Respective values in older adults (≥65 years) were 70.4% for males and 74.7% for females. About 19.3% of adult males and 37.9% of adult females presented abdominal obesity. Correspondent values in older adults were 32.1%, for males, and 69.7%, for females. In adults, low educational level was related to an increased risk for overweight (OR = 2.54; 95% CI: 2.08–3.09), obesity (OR = 2.76; 95% CI: 2.20–3.45), and abdominal obesity (OR = 5.48; 95% CI: 4.60–6.52). This reinforces the importance of adjusting public health strategies for educational level.

Objectively Measured Physical Activity and Body Mass Index in Preschool Children

Aim. To examine the association between objectively measured physical activity (PA) and body mass index (BMI) in preschool children. Methods. The study comprised 281 children (55.9% boys) aged from 4 to 6 years. PA was measured by accelerometer. Children were categorized as non-overweight (NOW) and overweight/obese (OW) according to the sex-adjusted BMI z-score (<1 and ≥1, resp.). Results. Total and moderate intensity PA were not associated with BMI. We observed that a higher proportion of OW children were classified as low-vigorous PA compared to their NOW peers (43.9 versus 32.1%, resp., P > .05). Logistic regression analysis showed that children with low-vigorous PA had higher odds ratio (OR) to be classified as OW compared to those with high-vigorous PA (OR = 4.4; 95% CI: 1.4–13.4; P = .008) after adjusting for BMI at first and second years of life and other potential confounders. Conclusion. The data suggests that vigorous PA may play a key role in the obesity development already at pre-school age.

Associations between body mass index, waist circumference and body shape index with resting blood pressure in Portuguese adolescents

Background: Elevated blood pressure (BP) in childhood and adolescence is associated with overweight and obesity. Recently a body shape index (ABSI) has been suggested as superior to body mass index (BMI, kg/m2) and waist circumference (WC) as a measure of disease risk. Objective: To examine the association between ABSI, BMI, WC and BP in Portuguese adolescents and to consider the role of ABSI, BMI and WC when examining this issue in adolescents. Methods and procedures: Height, body mass, WC and resting blood pressure were assessed in 445 Portuguese adolescents (252 girls and 193 boys) aged 10–17 years. Results: ABSI, BMI and WC were all significantly related to both SBP and DBP (all p = 0.001 or better). ABSI, BMI and WC were all significant predictors of SBP and DBP for the whole sample and when analysed in separate gender groups (p = 0.001 or better in all cases). However, in all cases ABSI was a better predictor of BP than BMI or WC. Conclusions: Although BMI and WC significantly predict resting BP in adolescents, the use of ABSI explained a greater amount of the variance in BP in this population. When examining the effect of weight status on BP, researchers should consider use of ABSI alongside BMI.

Metabolic syndrome, physical activity and cardiac autonomic function

Our primary aim was to investigate the associations that components of metabolic syndrome and physical activity have with cardiac autonomic nervous system activity as estimated by heart rate variability (HRV) in young adults free of metabolic abnormalities. We also aimed to identify predictors of 3‐year changes in HRV.

Sitting time and body mass index, in a Portuguese sample of men: results from the Azorean Physical Activity and Health Study (APAHS).

The aim of this study was to verify the relation between body mass index (BMI) and sitting time in a sample of 4,091 Azorean men. BMI was calculated from self-reported weight and height. Total physical activity (PA) time and total sitting time were assessed with the IPAQ (short version). Linear Regression analysis showed that total sitting time (hours/day) was positively associated with BMI (B = 0.078; p < 0.001) after adjustments for age, meal frequency, alcohol and tobacco consumptions, island of residence, education level and total PA time. Although the cross sectional design precludes us from establishing causality, our findings emphasize the importance of reducing sedentary behavior to decrease the risk of obesity.