Factors associated with physical activity in young people with haemophilia A on prophylaxis.

INTRODUCTION: Physical activity (PA) is influenced by numerous factors, and the literature describing why people with haemophilia (PWH) are physically active or not is inconclusive. AIMS: To investigate factors associated with PA (mean min/day in light (LPA), moderate (MPA), vigorous (VPA) and total PA, and proportion meeting World Health Organization (WHO) weekly moderate-to-vigorous (MVPA) recommendations) among young PWH A. METHODS: Forty PWH A on prophylaxis from the HemFitbit study were included. PA was measured using Fitbit devices and participant characteristics were collected. Potential factors associated with PA were investigated by univariable linear regression models for continuous PA outcomes, and descriptively for teenagers meeting/not meeting WHO MVPA recommendations only, because all except one adult met PA recommendations. RESULTS: Mean age (n = 40) was 19.5 years (SD 5.7). Annual bleeding rate was nearly zero and joint scores were low. We found an increase of four min/day in LPA (95% confidence interval (CI) 1-7) per year increase in age. Participants with 'Haemophilia Early Arthropathy Detection with Ultrasound' (HEAD-US) score ≥1 engaged in mean 14 min/day less MPA (95% CI -23.2 to -3.8), and 8 min less VPA (95% CI -15.0 to -0.4) compared to participants with HEAD-US score 0. Teenagers who met PA recommendations had slightly better joint status compared to those who did not meet recommendations. CONCLUSION: These findings indicate that presence of mild arthropathy does not affect LPA but may have a negative impact on PA of higher intensities. Early start of prophylaxis may be an important determinant of PA.

Physical activity in Norwegian teenagers and young adults with haemophilia A compared to general population peers.

INTRODUCTION: Limited evidence exists on objectively measured habitual physical activity (PA) of young people with haemophilia (PWH). AIMS: To compare different outcomes of objective PA between young PWH A and controls using a commercial activity tracker. METHODS: We enrolled males aged 13-30 years with moderate and severe haemophilia A, without inhibitors on regular prophylaxis. PA was measured with the activity tracker Fitbit Charge 3 for 12 weeks. Control group data was obtained from ≈60,000 Fitbit users, matched on age, sex and measurement period. PA variables [steps, intensities, volume, activity types, exercise frequencies and proportion meeting the World Health Organization's moderate-to-vigorous PA (MVPA) recommendations] were compared between groups descriptively and using Welch's two-sample t-test and two-sample test of proportions. RESULTS: Forty PWH A were enrolled (mean age 19.5 years, 50% teenagers, 50% adults, three (7.5%) with moderate and 37 (92.5%) with severe haemophilia). Mean daily steps and minutes MVPA were similar between PWH and controls. PWH spent more time in light PA (mean 227 vs. 192 min/day, P = .033) and exercised more frequently (mean 5.6 vs. 3.9 exercise sessions/week, P < .001). Among teenagers, 40% PWH and 8% controls reached MVPA recommendations, compared to 95% and 100% among adults. The most common type of PA was walking. CONCLUSION: This cohort of young PWH A on prophylactic treatment had PA levels comparable to controls. Still, a considerable proportion of teenagers did not meet the recommended weekly volume of MVPA, and we encourage clinicians to have a particular focus on promoting PA for this group.

Comparison of free-living physical activity measurements between ActiGraph GT3X-BT and Fitbit Charge 3 in young people with haemophilia.

INTRODUCTION: Measurement of physical activity (PA) using commercial activity trackers such as Fitbit devices has become increasingly popular, also for people with haemophilia (PWH). The accuracy of the Fitbit model Charge 3 has not yet been examined. AIMS: To compare the Fitbit Charge 3 against the research-grade accelerometer ActiGraph GT3X-BT in measuring average daily steps and minutes spent in different PA intensities. METHODS: Twenty-four young PWH wore a wrist-worn Fitbit Charge 3 and hip-worn ActiGraph GT3X-BT simultaneously for seven consecutive days in free-living conditions. Correlation of and differences between the devices for daily averages of PA parameters were assessed using Pearson's correlation coefficient and paired t-test, respectively. Agreement between devices was assessed using Bland-Altman plots. RESULTS: Twenty participants (mean age 21.8) were included in the analyses. We found moderate to high correlations between Fitbit and ActiGraph measured daily averages for all PA variables, but statistically significant differences between devices for all variables except daily minutes of moderate PA. Fitbit overestimated average daily steps, minutes of light, vigorous and moderate-to-vigorous PA. Bland-Altman plots showed a measurement bias between devices for all parameters with increasing overestimation by the Fitbit for higher volumes of PA. CONCLUSION: The Fitbit Charge 3 overestimated steps and minutes of light, moderate and moderate-to-vigorous PA as compared to the ActiGraph GT3X-BT, and this bias increased with PA volume. The Fitbit should therefore be used with caution in research, and we advise users of the device to be cognizant of this overestimation.

The effect of a school-based intervention on physical activity, cardiorespiratory fitness and muscle strength: the School in Motion cluster randomized trial.

BACKGROUND: Physical activity (PA) declines throughout adolescence, therefore PA promotion during this period is important. We analyzed the effect of two school-based PA interventions on daily PA levels, cardiorespiratory fitness (CRF) and muscle strength among adolescents. METHODS: For the nine-month School in Motion intervention study (ScIM), we cluster-randomized 30 Norwegian secondary schools (N = 2084, mean age [SD] = 14 [0.3] years) to one of three study arms. The physically active learning (PAL) intervention included 30 min physically active learning, 30 min PA and a 60 min physical education (PE) lesson per week. The Don't worry-Be happy (DWBH) intervention included a 60 min PA lesson and a 60 min PE lesson per week, both tailored to promote friendships and wellbeing. Both intervention arms were designed to engage the adolescents in 120 min of PA per week in addition to recess and mandatory PE lessons. The control group continued as per usual, including the standard amount of mandatory PE. PA (main outcome) was assessed by accelerometers, CRF and muscle strength (secondary outcomes) were assessed by an intermittent running test and selected tests from the Eurofit test battery. RESULTS: Daily PA and time spent in moderate- to vigorous-intensity PA (MVPA) decreased in all groups throughout the intervention. The mean difference in PA level and MVPA for participants in the PAL-intervention arm was 34.7 cpm (95% CI: 4.1, 65.3) and 4.7 min/day (95% CI: 0.6, 8.8) higher, respectively, compared to the control arm. There were no significant intervention effects on daily PA level, MVPA or time spent sedentary for adolescents in the DWBH-intervention arm. Adolescents in the PAL-intervention arm increased distance covered in the running test compared to controls (19.8 m, 95% CI: 10.4, 29.1), whilst a negative intervention effect was observed among adolescents in the DWBH-intervention arm (- 11.6 m, 95% CI: - 22.0, - 1.1). CONCLUSION: The PAL-intervention resulted in a significantly smaller decrease in daily PA level, time spent in MVPA, and increased CRF compared to controls. Our results indicate that a teacher-led intervention, including three unique intervention components, is effective in curbing the decline in PA observed across our cohort and improving CRF. TRIAL REGISTRATION: ClinicalTrials.gov ID nr: NCT03817047 . Registered 01/25/2019 'retrospectively registered'.

Are weight-related attitudes and behaviours associated with the accuracy of BMI derived from self-reported weight and height among 13-year-olds?

AIMS: The aim was to explore the association between weight-related attitudes and behaviours and the accuracy of body mass index (BMI) derived from self-reported weight and height. METHODS: A total of 828 adolescents from the Health In Adolescents study were included. Self-reported and objective weight and height data were collected, and BMI was computed. Information about weight-related attitudes and behaviours was obtained. The association between weight-related attitudes and behaviours and the difference between BMI computed from self-reported and objective measures was assessed using generalized linear mixed model analyses. RESULTS: BMI was under-reported by overweight girls (p<0.001) and boys (p<0.001) compared to their normal weight counterparts. Underweight girls on the other hand over-reported their BMI (p=0.002). Girls who reported trying to lose weight under-reported their BMI compared to girls who had not tried to do anything about their weight (p=0.02). Girls who perceived their weight as being too much under-reported their BMI compared to girls who thought their weight was ok, the association was however borderline significant (p=0.06); this association was also found among boys (p=0.03). Self-weighing and the reported importance of weight for how adolescents perceive themselves were not associated with the accuracy of BMI. CONCLUSIONS: weight perception and weight control behaviour among girls only were related to the accuracy of self-reported BMI; no association was found with self-weighing behaviour and the perceived importance of weight for how adolescents perceive themselves. Knowledge of such factors will allow for a better interpretation and possibly adjustment/correction of results of surveys based on self-reported weight and height data.

Post-intervention effects on screen behaviours and mediating effect of parental regulation: the HEalth In Adolescents study--a multi-component school-based randomized controlled trial.

BACKGROUND: To improve effectiveness of future screen behaviour interventions, one needs to know whether an intervention works via the proposed mediating mechanisms and whether the intervention is equally effective among subgroups. Parental regulation is identified as a consistent correlate of screen behaviours, but prospective evidence as well as the mediation role of parental regulation is largely lacking. This study investigated post-intervention main effects on screen behaviours in the HEIA-intervention--a Norwegian school-based multiple-behaviour study, as well as mediation effects of parental regulation by adolescents' and parents' report. In addition, moderating effects of gender and weight status on the intervention and mediating effects were explored. METHODS: Participating schools were randomized to control (n=25) or intervention (n=12) condition. Adolescents (n=908 Control; 510 Intervention) self-reported their weekday and weekend TV-viewing and computer/game-use. Change in adolescents' behaviours was targeted through school and parents. Adolescents, mothers (n=591 Control; 244 Interventions) and fathers (n=469 Control; 199 Intervention) reported parental regulation of the screen behaviours post-intervention (at 20 month). The product-of-coefficient test using linear regression analysis was conducted to examine main and mediating effects. RESULTS: There was no intervention effect on the screen behaviours in the total sample. Gender moderated effect on weekend computer/game-use, while weight status moderated the effect on weekday TV-viewing and computer/game-use. Stratified analyses showed a small favourable intervention effect on weekday TV-viewing among the normal weight. Parental regulation did not mediate change in the screen behaviours. However, stronger parental regulation was associated with less TV-viewing and computer/game-use with effects being conditional on adolescents' versus parental reports. Parental regulation of the screen behaviours, primarily by the parental report, was associated with change in the respective behaviours. CONCLUSION: Multiple behaviour intervention may not affect all equally well, and the effect may differ by weight status and gender. In future interventions parents should be encouraged to regulate their adolescents' TV-viewing and computer/game-use on both weekdays and weekends as parental regulation was identified as a determinant of these screen behaviours. However, future intervention studies may need to search for more effective intervention strategies targeting parental regulation. TRIAL REGISTRATION: Current Controlled Trials ISRCTN98552879.

Effects of a 20-month cluster randomised controlled school-based intervention trial on BMI of school-aged boys and girls: the HEIA study.

BACKGROUND: School-based interventions that target prevention of overweight and obesity in children have been tested with mixed results. Thus, successful interventions are still called for. The aim of the present study was to investigate effects of a multicomponent school-based intervention programme targeting physical activity, sedentary and dietary behaviours on anthropometric outcomes. METHODS: A 20-month intervention was evaluated in a cluster randomised, controlled study of 1324 11-year-olds. Outcome variables were body mass index (BMI), BMI-for-age z-score (BMIz), waist circumference (WC), waist-to-height ratio (WTHR) and weight status (International Obesity Task Force's cut-offs). Weight, height and WC were measured objectively; pubertal status was self-reported and parental education was self-reported by the parents. Intervention effects were determined by one-way analysis of covariance and logistic regression, after checking for clustering effects of school, and moderating effects of gender, pubertal status and parental education. RESULTS: Beneficial effects were found for BMI (p=0.02) and BMIz (p=0.003) in girls, but not in boys. While a beneficial effect was found for BMI (p=0.03) in participants of parents reporting a high level of education, a negative effect was found for WTHR in participants with parents reporting a low level of education (p=0.003). There were no intervention effects for WC and weight status. CONCLUSIONS: A multicomponent 20-month school-based intervention had a beneficial effect on BMI and BMIz in adolescent girls, but not in boys. Furthermore, children of higher educated parents seemed to benefit more from the intervention, and this needs attention in future interventions to avoid further increase in social inequalities in overweight and obesity.

Physical Activity, Fitness, and Cardiovascular Disease Risk in Adolescent Childhood Cancer Survivors Compared to Controls: The Physical Activity in Childhood Cancer Survivors Study.

Purpose: Childhood cancer survivors have increased risk of cardiac late effects that can be potentially mitigated by physical activity and fitness. We aimed to (1) compare cardiovascular disease (CVD) risk between survivors and controls, and (2) examine whether the associations of moderate-to-vigorous physical activity (MVPA), cardiorespiratory fitness (CRF), and musculoskeletal fitness (MSF) with CVD risk factors differed between survivors and controls. Methods: Within the Physical Activity in Childhood Cancer Survivors (PACCS) study, we assessed CVD risk factors (android fat mass, systolic blood pressure [SBP], total cholesterol/high-density lipoprotein [HDL]-cholesterol, and glycosylated hemoglobin) in 157 childhood cancer survivors and 113 age- and sex-matched controls aged 9-18 years. We used multivariable mixed linear regression models to compare CVD risk factors between survivors and controls, and assess associations of MVPA, CRF, and MSF with CVD risk factors. Results: Compared with controls, survivors had more android fat mass (861 vs. 648 g, p = 0.001) and lower SBP (114 vs. 118 mmHg, p = 0.002). MVPA, CRF, and MSF were associated with lower levels of android fat mass and total cholesterol/HDL-cholesterol, and higher SBP in survivors. Associations of MVPA, CRF, and MSF with CVD risk factors were similar in survivors and controls (Pinteraction > 0.05), except the associations of CRF and MSF with android fat mass, which were stronger in survivors than in controls (Pinteraction ≤ 0.001). Conclusion: Owing to higher levels of android fat mass and its stronger association with physical fitness in childhood cancer survivors compared with controls, survivors should get targeted interventions to increase fitness to reduce future risk of CVD.

Intervention effects on physical activity: the HEIA study - a cluster randomized controlled trial.

BACKGROUND: Although school-based interventions to promote physical activity in adolescents have been suggested in several recent reviews, questions have been raised regarding the effects of the strategies and the methodology applied and for whom the interventions are effective. The aim of the present study was to investigate effects of a school-based intervention program: the HEalth in Adolescents (HEIA) study, on change in physical activity, and furthermore, to explore whether potential effects varied by gender, weight status, initial physical activity level and parental education level. METHODS: This was a cluster randomized controlled 20 month intervention study which included 700 11-year-olds. Main outcome-variable was mean count per minute (cpm) derived from ActiGraph accelerometers (Model 7164/GT1M). Weight and height were measured objectively. Adolescents reported their pubertal status in a questionnaire and parents reported their education level on the consent form. Linear mixed models were used to test intervention effects and to account for the clustering effect of sampling by school. RESULTS: The present study showed an intervention effect on overall physical activity at the level of p=0.05 with a net effect of 50 cpm increase from baseline to post intervention in favour of the intervention group (95% CI -0.4, 100). Subgroup analyses showed that the effect appeared to be more profound among girls (Est 65 cpm, CI 5, 124, p=0.03) and among participants in the low-activity group (Est 92 cpm, CI 41, 142, p<0.001), as compared to boys and participants in the high-activity group, respectively. Furthermore, the intervention affected physical activity among the normal weight group more positively than among the overweight, and participants with parents having 13-16 years of education more positively than participants with parents having either a lower or higher number of years of education. The intervention seemed to succeed in reducing time spent sedentary among girls but not among boys. CONCLUSIONS: A comprehensive but feasible, multi-component school-based intervention can affect physical activity patterns in adolescents by increasing overall physical activity. This intervention effect seemed to be more profound in girls than boys, low-active adolescents compared to high-active adolescents, participants with normal weight compared to the overweight, and for participants with parents of middle education level as opposed to those with high and low education levels, respectively. An implementation of the HEIA intervention components in the school system may have a beneficial effect on public health by increasing overall physical activity among adolescents and possibly among girls and low-active adolescents in particular.

Are screen-based sedentary behaviors longitudinally associated with dietary behaviors and leisure-time physical activity in the transition into adolescence?

BACKGROUND: There is a need for more longitudinal studies investigating the associations between screen-based sedentary behaviors (SB), dietary behaviors and leisure-time physical activity (PA). METHODS: In the HEIA cohort study, 908 children were followed from age 11 to age 13 (September 2007-May 2009). The children self-reported their intake of fruits, vegetables, soft drinks with sugar and snacks. TV/DVD use, computer/game use and leisure-time PA were also self-reported. Multilevel generalized linear mixed model analysis was used to assess longitudinal associations between the screen-based SB and each of the two other behaviors. RESULTS: Twenty-month changes in TV/DVD use and computer/game use were positively associated with changes in the consumption of soft drinks with sugar and unhealthy snacks in the same period; and inversely associated with change in vegetable consumption. Change in computer/game use was also inversely related to change in fruit consumption. An inverse but non-substantive association was found between change in TV/DVD use and change in leisure-time PA. Change in computer/game use was not significantly associated with change in leisure-time PA. CONCLUSIONS: Changes in screen-based SB were associated with multiple unfavorable changes in dietary habits, although the associations were weak. These associations need to be further investigated in intervention/experimental studies, to assess whether changing screen-based SB will result in clinically relevant changes in dietary behaviors. However, the findings of this study suggest that screen-based SB and leisure-time PA are largely independent behaviors which should be addressed separately in health promotion activities.

Adolescents' prospective screen time by gender and parental education, the mediation of parental influences.

BACKGROUND: The present study investigated associations in gender dyads of parents' and adolescents' time spent on television and video viewing (TV/DVD), and computer and electronic game use (PC/games) at the ages of 11 and 13 years. Possible mediating effects of parental modelling and parental regulation in the relationship between parental education and adolescents' prospective TV/DVD and PC/game time were further examined. METHODS: A total of 908 adolescents, participating at both ages 11 and 13 years in the Norwegian HEalth In Adolescents (HEIA) cohort study (2007-2009), were included in the analyses. Data on adolescents', mothers' and fathers' self reported time spent on TV/DVD and PC/games were measured at both time points by questionnaires. Correlation coefficients were used to examine gender dyads of parents' and adolescents' reports. Mediation analyses using linear regression investigated possible mediation effects of parental modelling and parental regulation in the prospective relationship between parental education and adolescents' time spent on TV/DVD and PC/games between the ages of 11 and 13 years. RESULTS: Correlations of screen time behaviours in gender dyads of parents and adolescents showed significant associations in time spent on TV/DVD at the age of 11 and 13 years. Associations between mothers and sons and between fathers and daughters were also observed in time spent on PC/games at the age of 11 years. Maternal and paternal modelling was further found to mediate the relationship between parental education and adolescents' prospective TV/DVD time between the ages of 11 and 13 years. No mediation effect was observed for parental regulation, however a decrease in both maternal and paternal regulation at the age of 11 years significantly predicted more TV/DVD time among adolescents at the age of 13 years. CONCLUSION: Cross-sectional and longitudinal relationships were observed in gender dyads of parents' and adolescents' screen time behaviours at the ages of 11 and 13 years, and further studies including both parents and their children should be emphasized. Moreover, maternal and paternal modelling were found to be important target variables in interventions aiming to reduce social differences by parental education in adolescents' prospective time spent on TV/DVD.

Does tracking of dietary behaviours differ by parental education in children during the transition into adolescence?

OBJECTIVE: The present study investigates the changes and tracking of dietary behaviours in Norwegian 11-year-olds and examines the association between parental education and dietary tracking over a time period of 20 months. DESIGN: Longitudinal data from the Norwegian HEalth In Adolescents (HEIA) cohort study followed up at three time points (2007-2009). SETTING: Intakes of fruits, vegetables and snacks were assessed by frequency and intakes of sugar-sweetened soft drinks and squash were assessed by frequency and amount. Tracking of dietary behaviours was assessed by adolescents' relative position in rank over time and Cohen's kappa was used to measure tracking coefficients. Multinomial logistic regression analyses were performed to assess the association between parental education and the tracking of dietary behaviours. SUBJECTS: In total, 885 adolescents from the HEIA cohort study participated by answering Internet-based questionnaires at three time points. RESULTS: The results indicated that boys and girls maintained their relative position in rank of dietary intake over time, when grouped by baseline consumption. Fair to moderate tracking coefficients of dietary variables were observed. An inverse association was found between parental education and stability of soft drink and squash consumption during the 20 months. CONCLUSIONS: The observed tracking pattern indicates the importance of promoting healthy dietary behaviours at an even earlier age. Furthermore, interventions should focus particularly on adolescents from families with low parental education and their consumption of sugar-sweetened beverages.

Physical activity in 9-15 year-old pediatric cancer survivors compared to a nationwide sample.

INTRODUCTION: Sufficient physical activity (PA) has the potential to mitigate late effects of cancer, but objective data of PA levels in adolescents are scarce. The aim of this study was to investigate differences in PA behavior between childhood cancer survivors (CCS) and healthy peers. METHODS: PA levels of n = 74 CCS and n = 1304 healthy peers from the MoMo study aged 9-15 years were assessed with validated objective accelerometry and group means were compared. A binary multiple logistic regression was performed to investigate the potential predictors of PA. RESULTS: CCS spent significantly more time sedentary (p < 0.001) and less time in moderate-to-vigorous physical activity (p = 0.002) compared to the healthy cohort. Subgroup analysis revealed the largest deviations of PA levels for CCS aged 9-11 years who fulfilled international PA recommendations on significantly fewer days than MoMo (p < 0.01). Health conditions seem to be a predictor concerning the fulfillment of international PA recommendations by the WHO (p = 0.015). CONCLUSIONS: Our study identified vulnerable groups which seem to require targeted exercise and health behavior change programs to increase physical activity and reduce sedentary time. The presence of treatment sequelae as a significant predictor of insufficient physical activity underlines the need of multidisciplinary supportive care approaches.

Physical Activity Among Adolescent Cancer Survivors: The PACCS Study.

OBJECTIVES: Physical activity (PA) may modify risks of late effects after cancer. We aimed to examine levels of PA and sedentary time (ST) in a large, international sample of adolescent childhood cancer survivors in relation to sociodemographic and cancer-related factors and compare levels of PA and ST to reference cohorts. METHODS: Survivors from any cancer diagnosis who had completed cancer treatment ≥1 year ago, aged 9 to 16 years, were eligible for the multicenter Physical Activity in Childhood Cancer Survivors study. PA and ST were measured by ActiGraph GT3X+ accelerometers. We performed linear regression analyses to assess factors associated with moderate-to-vigorous PA (MVPA) and ST, and compared marginal means of total PA, MVPA, and ST in 432 survivors to sex- and age-stratified references (2-year intervals) using immediate t-tests for aggregated data. RESULTS: Among survivors, 34% fulfilled the World Health Organization's PA recommendation of ≥60 min of daily MVPA on average and their ST was 8.7 hours per day. Being female, older, overweight, a survivor of central nervous system tumor, or having experienced relapse were associated with lower MVPA and/or higher ST. Generally, male survivors spent less time in MVPA compared with references, whereas female survivors had similar levels. Both male and female survivors had higher ST than references in nearly all age groups. CONCLUSIONS: The low PA and high ST in this large sample of adolescent childhood cancer survivors is worrisome. Combined, our results call for targeted interventions addressing both PA and ST in follow-up care after childhood cancer.

Effects of Aerobic Exercise on Cardiorespiratory Fitness, Cardiovascular Risk Factors, and Patient-Reported Outcomes in Long-Term Breast Cancer Survivors: Protocol for a Randomized Controlled Trial.

BACKGROUND: Anthracycline-based chemotherapy has been mainstay of adjuvant breast cancer therapy for decades. Although effective, anthracyclines place long-term breast cancer survivors at risk of late effects, such as reduced cardiorespiratory fitness and increased risk of cardiovascular disease. Previous research has shown beneficial effects of exercise training on cardiorespiratory fitness, but the effects of exercise on limiting factors for cardiorespiratory fitness, cardiovascular risk factors, and patient-reported outcomes in long-term survivors are less clear. Whether previous exposure to breast cancer therapy modulates the effects of exercise is also unknown. OBJECTIVE: The primary aim of the CAUSE (Cardiovascular Survivors Exercise) trial is to examine the effect of aerobic exercise on cardiorespiratory fitness in anthracycline-treated long-term breast cancer survivors. Secondary aims are to examine effects of exercise training on limiting factors for cardiorespiratory fitness, cardiovascular risk factors, and patient-reported outcomes, and to compare baseline values and effects of exercise training between similar-aged women with and those without prior breast cancer. A third aim is to examine the 24-month postintervention effects of aerobic exercise on primary and secondary outcomes. METHODS: The CAUSE trial is a 2-armed randomized controlled trial, where 140 long-term breast cancer survivors, 8-12 years post diagnosis, are assigned to a 5-month nonlinear aerobic exercise program with 3 weekly sessions or to standard care. Seventy similar-aged women with no history of cancer will undergo the same exercise program. Cardiorespiratory fitness measured as peak oxygen consumption (VO2peak), limiting factors for VO2peak (eg, cardiac function, pulmonary function, hemoglobin mass, blood volume, and skeletal muscle characteristics), cardiovascular risk factors (eg, hypertension, diabetes, dyslipidemia, obesity, physical activity level, and smoking status), and patient-reported outcomes (eg, body image, fatigue, mental health, and health-related quality of life) will be assessed at baseline, post intervention, and 24 months post intervention. RESULTS: A total of 209 patients were included from October 2020 to August 2022, and postintervention assessments were completed in January 2023. The 24-month follow-up will be completed in February 2025. CONCLUSIONS: The findings from the CAUSE trial will provide novel scientific understanding of the potential benefits of exercise training in long-term breast cancer survivors. TRIAL REGISTRATION: ClinicalTrials.gov NCT04307407; https://clinicaltrials.gov/ct2/show/NCT04307407. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/45244.

Correction: Effects of Aerobic Exercise on Cardiorespiratory Fitness, Cardiovascular Risk Factors, and Patient-Reported Outcomes in Long-Term Breast Cancer Survivors: Protocol for a Randomized Controlled Trial.

[This corrects the article DOI: 10.2196/45244.].

Mid-way and post-intervention effects on potential determinants of physical activity and sedentary behavior, results of the HEIA study - a multi-component school-based randomized trial.

BACKGROUND: There is limited knowledge as to whether obesity prevention interventions are able to produce change in the determinants hypothesized to precede change in energy balance-related behaviors in young people. The aim of this study was to evaluate the effect of a multi-component intervention on a wide range of theoretically informed determinants of physical activity (PA) and sedentary behavior (SB). Moderation effects of gender, weight status and parental education level and whether the perceived intervention dose received influenced the effects were also explored. METHODS: The HEIA study was a 20-month school-based, randomized controlled trial to promote healthy weight development. In total, 1418 11-year-olds participated at baseline and post-intervention assessment. Enjoyment, self-efficacy, perceived social support from parents, teachers and friends related to PA, perceived parental regulation of TV-viewing and computer/game-use and perceived social inclusion at schools were examined by covariance analyses to assess overall effects and moderation by gender, weight status and parental education, mid-way and post-intervention. Covariance analyses were also used to examine the role of intervention dose received on change in the determinants. RESULTS: At mid-way enjoyment (p = .03), perceived social support from teachers (p = .003) and self-efficacy (p = .05) were higher in the intervention group. Weight status moderated the effect on self-efficacy, with a positive effect observed among the normal weight only. At post-intervention results were sustained for social support from teachers (p = .001), while a negative effect was found for self-efficacy (p = .02). Weight status moderated the effect on enjoyment, with reduced enjoyment observed among the overweight. Moderation effects for parental education level were detected for perceived social support from parents and teachers. Finally, positive effects on several determinants were observed among those receiving a high as opposed to a low intervention dose. CONCLUSION: The intervention affected both psychological and social-environmental determinants. Results indicate that social support from teachers might be a potential mediator of PA change, and that overweight adolescents might be in need of specially targeted interventions to avoid reducing their enjoyment of PA. Further studies should continue to assess how intervention effectiveness is influenced by the participants' self-reported dose of intervention received.

Mechanical and free living comparisons of four generations of the Actigraph activity monitor.

BACKGROUND: More studies include multiple generations of the Actigraph activity monitor. So far no studies have compared the output including the newest generation and investigated the impact on the output of the activity monitor when enabling the low frequency extension (LFE) option. The aims were to study the responses of four generations (AM7164, GT1M, GT3X and GT3X+) of the Actigraph activity monitor in a mechanical setup and a free living environment with and without enabling the LFE option. METHODS: The monitors were oscillated in a mechanical setup using two radii in the frequency range 0.25-3.0 Hz. Following the mechanical study a convenience sample (N = 20) wore three monitors (one AM7164 and two GT3X) for 24 hours. RESULTS: The AM7164 differed from the newer generations across frequencies (p < 0.05) in the mechanical setup. The AM7164 produced a higher output at the lower and at the highest intensities, whereas the output was lower at the middle intensities in the mid-range compared to the newer generations. The LFE option decreased the differences at the lower frequencies, but increased differences at the higher. In free living, the mean physical activity level (PA) of the GT3X was 18 counts per minute (CPM) (8%) lower compared to the AM7164 (p < 0.001). Time spent in sedentary intensity was 26.6 minutes (95% CI 15.6 to 35.3) higher when assessed by the GT3X compared to the AM7164 (p < 0.001). Time spend in light and vigorous PA were 23.3 minutes (95% CI 31.8 to 14.8) and 11.7 minutes (95% CI 2.8 to 0.7) lower when assessed by the GT3X compared to the AM7164 (p < 0.05). When enabling the LFE the differences in the sedentary and light PA intensity (<333 counts*10 sec-1) were attenuated (p > 0.05 for differences between generations) thus attenuated the difference in mean PA (p > 0.05) when the LFE option was enabled. However, it did not attenuate the difference in time spend in vigorous PA and it introduced a difference in time spend in moderate PA (+ 3.0 min (95% CI 0.4 to 5.6)) between the generations. CONCLUSION: We observed significant differences between the AM7164 and the newer Actigraph GT-generations (GT1M, GT3X and GT3X+) in a mechanical setup and in free-living. Enabling the LFE option attenuated the differences in mean PA completely, but induced a bias in the moderate PA intensities.

Correlates of weight status among Norwegian 11-year-olds: The HEIA study.

BACKGROUND: The underlying mechanisms of overweight and obesity in adolescents are still not fully understood. The aim of this study was to investigate modifiable and non-modifiable correlates of weight status among 1103 Norwegian 11-year-old adolescents in the HEalth in Adolescents (HEIA) study, including demographic factors such as gender and parental education, and behavioral factors such as intake of sugar-sweetened beverages, snacks and breakfast consumption, watching TV and playing computer games, physical activity and sedentary time. METHODS: Weight and height were measured objectively, body mass index (BMI) was calculated and International Obesity Task Force cut-offs were used to define weight status. Physical activity and sedentary time were measured by accelerometers. Other behavioral correlates and pubertal status were self-reported by questionnaires. Parental education was reported by the parents on the consent form for their child. Associations were investigated using logistic regressions. RESULTS: There were gender differences in behavioral correlates of weight status but not for weight status itself. Adolescents with parents in the highest education category had a 46% reduced odds of being overweight compared to adolescents with parents in the lowest education category. Adolescents with parents with medium education had 42% lower odds of being overweight than adolescents with parents with the lowest education category. Level of parental education, breakfast consumption and moderate to vigorous physical activity were positively associated with being normal weight, and time watching TV was positively associated with being overweight for the total sample. Gender differences were detected; boys had a doubled risk of being overweight for every additional hour of watching TV per week, while for girls there was no association. CONCLUSIONS: The present study showed a social gradient in weight status in 11-year-olds. Both breakfast consumption and moderate to vigorous physical activity were inversely associated with weight status. No associations were found between intake of sugar-sweetened beverages and snacks, playing computer games and weight status. Watching TV was positively associated with weight status for boys but not for girls. Interventions are needed to gain more insight into the correlates of change in weight status.

Stability and change in screen-based sedentary behaviours and associated factors among Norwegian children in the transition between childhood and adolescence.

BACKGROUND: In order to inform interventions to prevent sedentariness, more longitudinal studies are needed focusing on stability and change over time in multiple sedentary behaviours. This paper investigates patterns of stability and change in TV/DVD use, computer/electronic game use and total screen time (TST) and factors associated with these patterns among Norwegian children in the transition between childhood and adolescence. METHODS: The baseline of this longitudinal study took place in September 2007 and included 975 students from 25 control schools of an intervention study, the HEalth In Adolescents (HEIA) study. The first follow-up took place in May 2008 and the second follow-up in May 2009, with 885 students participating at all time points (average age at baseline = 11.2, standard deviation ± 0.3). Time used for/spent on TV/DVD and computer/electronic games was self-reported, and a TST variable (hours/week) was computed. Tracking analyses based on absolute and rank measures, as well as regression analyses to assess factors associated with change in TST and with tracking high TST were conducted. RESULTS: Time spent on all sedentary behaviours investigated increased in both genders. Findings based on absolute and rank measures revealed a fair to moderate level of tracking over the 2 year period. High parental education was inversely related to an increase in TST among females. In males, self-efficacy related to barriers to physical activity and living with married or cohabitating parents were inversely related to an increase in TST. Factors associated with tracking high vs. low TST in the multinomial regression analyses were low self-efficacy and being of an ethnic minority background among females, and low self-efficacy, being overweight/obese and not living with married or cohabitating parents among males. CONCLUSIONS: Use of TV/DVD and computer/electronic games increased with age and tracked over time in this group of 11-13 year old Norwegian children. Interventions targeting these sedentary behaviours should thus be introduced early. The identified modifiable and non-modifiable factors associated with change in TST and tracking of high TST should be taken into consideration when planning such interventions.