Dyadic action control in overweight and obese couples: Effectiveness of a randomized controlled trial to promote physical activity.

BACKGROUND: Enhancing physical activity in overweight and obese individuals is an important means to promote health in this target population. The Health Action Process Approach (HAPA), which was the theoretical framework of this study, focuses on individual self-regulation variables for successful health behavior change. One key self-regulation variable of this model is action control with its three subfacets awareness of intentions, self-monitoring and regulatory effort. The social context of individuals, however, is usually neglected in common health behavior change theories. In order to integrate social influences into the HAPA, this randomized controlled trial investigated the effectiveness of a dyadic conceptualization of action control for promoting physical activity. METHODS/DESIGN: This protocol describes the design of a single-blind randomized controlled trial, which comprises four experimental groups: a dyadic action control group, an individual action control group and two control groups. Participants of this study are overweight or obese, heterosexual adult couples who intend to increase their physical activity. Blocking as means of a gender-balanced randomization is used to allocate couples to conditions and partners to either being the target person of the intervention or to the partner condition. The ecological momentary intervention takes place in the first 14 days after baseline assessment and is followed by another 14 days diary phase without intervention. Follow-ups are one month and six months later. Subsequent to the six-months follow-up another 14 days diary phase takes place.The main outcome measures are self-reported and accelerometer-assessed physical activity. Secondary outcome measures are Body Mass Index (BMI), aerobic fitness and habitual physical activity. DISCUSSION: This is the first study examining a dyadic action control intervention in comparison to an individual action control condition and two control groups applying a single-blind randomized control trial. Challenges with running couples studies as well as advantages and disadvantages of certain design-related decisions are discussed. This RCT was funded by the Swiss National Science Foundation (PP00P1_133632/1) and was registered on 27/04/2012 at http://www.isrctn.com/ISRCTN15705531.

Predicting Physical Activity in Adolescents: The Role of Compensatory Health Beliefs within the Health Action Process Approach

Objective: Compensatory health beliefs (CHBs), defined as beliefs that healthy behaviours can compensate for unhealthy behaviours, may be one possible factor hindering people in adopting a healthier lifestyle. This study examined the contribution of CHBs to the prediction of adolescents’ physical activity within the theoretical framework of the Health Action Process Approach (HAPA). Design: The study followed a prospective survey design with assessments at baseline (T1) and two weeks later (T2). Method: Questionnaire data on physical activity, HAPA variables and CHBs were obtained twice from 430 adolescents of four different Swiss schools. Multilevel modelling was applied. Results: CHBs added significantly to the prediction of intentions and change in intentions, in that higher CHBs were associated with lower intentions to be physically active at T2 and a reduction in intentions from T1 to T2. No effect of CHBs emerged for the prediction of self-reported levels of physical activity at T2 and change in physical activity from T1 to T2. Conclusion: Findings emphasise the relevance of examining CHBs in the context of an established health behaviour change model and suggest that CHBs are of particular importance in the process of intention formation.

Influence of physical activity and acute exercise on cognitive performance and saliva testosterone in preadolescent school children

We investigated whether the chronic physical activity participation had an impact on the acute effects of a short bout of 12 min of intensive physical activity on cognitive performance and testosterone concentration in primary school students (n = 42, mean age = 9.69, SD = .44; experimental group (EG), n = 27; control group (CG), n = 15). Furthermore, we looked for associations between testosterone concentration and cognitive performance. After the intervention, participants of the EG showed better cognitive performances as compared to the CG. We further observed a significant group (EG, CG) test (pre, post) activity level (high, low) interaction. Post hoc pairwise comparisons revealed that after acute physical activity the testosterone concentration was diminished only in habitually low active children. The results indicate that intensive physical activity only attenuates the reactivity of the hypothalamic-pituitary-gonadal axis in habitually low active preadolescents, but had a beneficial effect on cognitive performance for all participants independent of their physical activity level and testosterone.

Promoting physical activity in overweight couples: Effectiveness of a dyadic action control trial (DYACTIC)

Background: Health behavior change models identify effective self-regulatory skills for behavioral change, but the social context is usually neglected. This study investigated the effectiveness of a dyadic conceptualization of action control for promoting physical activity. Methods: 121 overweight individuals and their partners were randomly allocated to one of two experimental (dyadic vs. individual action control) and two control conditions. Participants completed questionnaires at baseline (T1) and four weeks later (T2) including measures of action control and 7-day recall physical activity. Findings: Results showed that action control signi+cantly increased from T1 to T2 and was overall higher in the experimental conditions compared to control conditions. In terms of physical activity, no overall intervention effect emerged. However, post hoc analyses revealed higher mean levels of sport activities in the dyadic intervention group compared to all other groups. Discussion: Overall, +ndings provide +rst support for the usefulness of a dyadic action control intervention, and suggest further investigation of objective measures of physical activity and secondary outcomes

The effects of qualitatively different acute physical activity interventions in real-world settings on executive functions in preadolescent children

There is growing evidence indicating a positive effect of acute physical activity on cognitive performance in children. Most of the evidence originates, however, from studies in highly controlled laboratory settings. The aim of the present study was to investigate whether the same effects can be found in more real-world settings. We examined the effects of qualitatively different acute physical activity interventions on the three core dimensions of executive functions (updating, inhibition, shifting). In an experimental between-subject design, 219 ten to twelve year-olds were assigned to one of four conditions which varied systematically in physical activation and cognitive engagement. Executive functions were measured before and immediately after the intervention. Contrary to the hypothesis, no effects of acute physical activity with and without cognitive engagement were found on executive functions in the overall sample. Only children with higher fitness and/or higher academic achievement benefitted from the interventions in terms of their updating performance. Thus, the results indicate that it may be more difficult to attain positive effects through acute physical activity in real-world settings than in laboratory settings and that physiological and cognitive requirements may have to be adjusted to individual capacity to make an intervention effective.

Physical activity intensity and surrogate markers for cardiovascular health in adolescents

We examined the impact of physical activity (PA) on surrogate markers of cardiovascular health in adolescents. 52 healthy students (28 females, mean age 14.5 ± 0.7 years) were investigated. Microvascular endothelial function was assessed by peripheral arterial tonometry to determine reactive hyperemic index (RHI). Vagal activity was measured using 24 h analysis of heart rate variability [root mean square of successive normal-to-normal intervals (rMSSD)]. Exercise testing was performed to determine peak oxygen uptake ([Formula: see text]) and maximum power output. PA was assessed by accelerometry. Linear regression models were performed and adjusted for age, sex, skinfolds, and pubertal status. The cohort was dichotomized into two equally sized activity groups (low vs. high) based on the daily time spent in moderate-to-vigorous PA (MVPA, 3,000-5,200 counts(.)min(-1), model 1) and vigorous PA (VPA, >5,200 counts(.)min(-1), model 2). MVPA was an independent predictor for rMSSD (β = 0.448, P = 0.010), and VPA was associated with maximum power output (β = 0.248, P = 0.016). In model 1, the high MVPA group exhibited a higher vagal tone (rMSSD 49.2 ± 13.6 vs. 38.1 ± 11.7 ms, P = 0.006) and a lower systolic blood pressure (107.3 ± 9.9 vs. 112.9 ± 8.1 mmHg, P = 0.046). In model 2, the high VPA group had higher maximum power output values (3.9 ± 0.5 vs. 3.4 ± 0.5 W kg(-1), P = 0.012). In both models, no significant differences were observed for RHI and [Formula: see text]. In conclusion, in healthy adolescents, PA was associated with beneficial intensity-dependent effects on vagal tone, systolic blood pressure, and exercise capacity, but not on microvascular endothelial function.

Can a website-delivered computer-tailored physical activity intervention be acceptable, usable, and effective for older people?

Despite the numerous health benefits, population physical activity levels are low and declining with age. A continued increase of Internet access allows for website-delivered interventions to be implemented across age-groups, though older people have typically not been considered for this type of intervention. Therefore, the purpose of this study was to evaluate a website-delivered computer-tailored physical activity intervention, with a specific focus on differences in tailored advice acceptability, website usability, and physical activity change between three age-groups. To mimic "real-life" conditions, the intervention, which provided personalized physical activity feedback delivered via the Internet, was implemented and evaluated without any personal contact for the entire duration of the study. Data were collected online at baseline, 1-week, and 1-month follow-up and analyzed for three age-groups (≤44, 45-59, and ≥60 years) using linear mixed models. Overall, 803 adults received the intervention and 288 completed all measures. The oldest age-group increased physical activity more than the other two groups, spent the most time on the website, though had significantly lower perceived Internet self-confidence scores when compared with the youngest age-group. No differences were found in terms of website usability and tailored advice acceptability. These results suggest that website-delivered physical activity interventions can be suitable and effective for older aged adults.

Actigraphic monitoring of physical activity in clinical trials in schizophrenia

Schizophrenia is still associated with poor outcome, which is mainly related to negative symptoms, reduced physical activity and low quality of life. Physical activity can be objectively measured without distress using wrist actigraphy. The activity levels during the wake periods of the day have been informative on psychopathology and antipsychotic medication. Several studies demonstrated prominent negative symptoms to be associated with reduced activity levels with strongest correlations in chronic patients. Particularly, the avolition score is correlated with reduced activity levels. Moreover, activity levels differ between DSM-IV schizophrenia spectrum disorders and subtypes as well as between patients treated with olanzapine or risperidone. The longitudinal course of activity levels during an psychotic episode demonstrates considerable variance between subjects. During a psychotic episode patients with low activity levels at baseline experience an amelioration of negative symptoms. In contrast, patients with high activity levels at baseline have stable low negative syndrome scores. Between psychotic episodes less variance is observed. Actigraphy is easily applied in schizophrenia and allows collecting large amounts of crosssectional or longitudinal data. With larger numbers of subjects in controlled trials, continuous recording of activity would foster the detection of different outcome trajectories, which may prove as useful groups to target interventions. In clinical trials, activity monitoring may supplement and validate measures of the negative syndrome and its avolition factor or serve as an outcome marker for physical activity, which is important for metabolic issues and quality of life.

Dynamic Activity-Related Incentives for Physical Activity.

The present studies adopted the theoretical framework of activity- and purpose-related incentives (Rheinberg, 2008) to explain the maintenance of physical activity. We hypothesized that activity-related incentives (e.g., “fun”) increase more than purpose-related incentives (e.g., “health”) between the initiation and maintenance phase of physical activity. Additionally, change in activity-related incentives was hypothesized to be a better predictor of maintenance of physical activity than change in purpose-related incentives. Two correlative field studies with rehabilitation patients (Study 1) and Nordic Walkers (Study 2) were conducted to test the hypotheses. Participants’ incentives of physical activity were measured at the beginning of exercising and two weeks (Study 1; T2) and three months (Study 2; T2) later. At T2, participants were asked for their current physical activity. Both studies showed a greater change of activity-related incentives than purpose-related incentives. Furthermore, change in activity-related incentives was more predictive of the maintenance of physical activity than change in purpose-related incentives. The results showed the important role of activity-related incentives in maintenance of physical activity. The theoretical contribution to physical activity maintenance research and practical implications for health promotion programs were discussed.

Physical Activity and Risk of Bleeding in Elderly Patients Taking Anticoagulants.

BACKGROUND Although the possibility of bleeding during anticoagulant treatment may limit patients from taking part in physical activity, the association between physical activity and anticoagulation-related bleeding is uncertain. OBJECTIVES To determine whether physical activity is associated with bleeding in elderly patients taking anticoagulants. PATIENTS/METHODS In a prospective multicenter cohort study of 988 patients aged ≥65 years receiving anticoagulants for venous thromboembolism, we assessed patients' self-reported physical activity level. The primary outcome was the time to a first major bleeding, defined as fatal bleeding, symptomatic bleeding in a critical site, or bleeding causing a fall in hemoglobin or leading to transfusions. The secondary outcome was the time to a first clinically-relevant non-major bleeding. We examined the association between physical activity level and time to a first bleeding using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate. RESULTS During a mean follow-up of 22 months, patients with a low, moderate, and high physical activity level had an incidence of major bleeding of 11.6, 6.3, and 3.1 events per 100 patient-years, and an incidence of clinically relevant non-major bleeding of 14.0, 10.3, and 7.7 events per 100 patient-years, respectively. A high physical activity level was significantly associated with a lower risk of major bleeding (adjusted sub-hazard ratio 0.40, 95%-CI 0.22-0.72). There was no association between physical activity and non-major bleeding. CONCLUSIONS A high level of physical activity is associated with a decreased risk of major bleeding in elderly patients receiving anticoagulant therapy. This article is protected by copyright. All rights reserved.

Physical activity in schizophrenia is higher in the first episode than in subsequent ones

Schizophrenia is frequently associated with abnormal motor behavior, particularly hypokinesia. The course of the illness tends to deteriorate in the first years. We aimed to assess gross motor activity in patients with a first episode (n = 33) and multiple episodes (n = 115) of schizophrenia spectrum disorders using wrist actigraphy. First episode patients were younger, had higher motor activity and reduced negative symptom severity. Covarying for age, chlorpromazine equivalents, and negative symptoms, first episode patients still had higher motor activity. This was also true after excluding patients with schizophreniform disorder from the analyses. In first episode patients, but not in patients with multiple episodes, motor activity was correlated with antipsychotic dosage. In conclusion, after controlling for variables related to disorder chronicity, patients with first episodes were still more active than patients with multiple episodes. Thus, reduced motor activity is a marker of deterioration in the course of schizophrenia spectrum disorders.