Physical Activity In Healthy Adults Research Articles

Identifying app components that promote physical activity: a group concept mapping study.

Digital interventions are a promising avenue to promote physical activity in healthy adults. Current practices recommend to include end-users early on in the development process. This study focuses on the wishes and needs of users regarding an a mobile health (mHealth) application that promotes physical activity in healthy adults, and on the differences between participants who do or do not meet the World Health Organization's recommendation of an equivalent of 150 minutes of moderate intensity physical activity. We used a mixed-method design called Group Concept Mapping. In a first phase, we collected statements completing the prompt "In an app that helps me move more, I would like to see/ do/ learn the following…" during four brainstorming sessions with physically inactive individuals (n=19). The resulting 90 statements were then sorted and rated by a new group of participants (n=46). Sorting data was aggregated, and (dis)similarity matrices were created using multidimensional scaling. Hierarchical clustering was applied using Ward's method. Analyses were carried out for the entire group, a subgroup of active participants and a subgroup of inactive participants. Explorative analyses further investigated ratings of the clusters as a function of activity level, gender, age and education. Six clusters of statements were identified, namely 'Ease-of-use and Self-monitoring', 'Technical Aspects and Advertisement', 'Personalised Information and Support', 'Motivational Aspects', 'Goal setting, goal review and rewards', and 'Social Features'. The cluster 'Ease-of-use and Self-monitoring' was rated highest in the overall group and the active subgroup, whereas the cluster 'Technical Aspects and Advertisement' was scored as most relevant in the inactive subgroup. For all groups, the cluster 'Social Features' was scored the lowest. Explorative analysis revealed minor between-group differences. The present study identified priorities of users for an mHealth application that promotes physical activity. First, the application should be user-friendly and accessible. Second, the application should provide personalized support and information. Third, users should be able to monitor their behaviour and compare their current activity to their past performance. Fourth, users should be provided autonomy within the app, such as over which and how many notifications they would like to receive, and whether or not they want to engage with social features. These priorities can serve as guiding principles for developing mHealth applications to promote physical activity in the general population.

The Usability of a Touchpad Active Video Game Controller for Individuals With Impaired Mobility: Observational Study.

Video games are a popular sedentary activity among people with impaired mobility; however, active video game hardware typically lacks accessibility and customization options for individuals with mobility impairments. A touchpad video game system can elicit moderate physical activity in healthy adults; however, it is unclear if this system is usable by adults with impaired mobility. The purpose of this study was to assess the usability of a touchpad video game controller system adapted for adults with impaired mobility. Additional outcomes explored were enjoyment, perceived exertion, self-efficacy, participant feedback, and researcher observations of gameplay. Participants played several video game titles for 20 minutes with a touchpad video game controller as they stood or sat in a chair or their wheelchair. Usability was assessed with the System Usability Scale (SUS) and the Health Information Technology Usability Evaluation Scale (Health-ITUES) surveys after gameplay. After each video game, participants reported enjoyment using a visual analog scale (0 to 100 mm) and a rating of perceived exertion using the OMNI 0 to 10 scale. Self-efficacy was measured before and after gameplay. Participants provided feedback at the end of their session. In total, 21 adults (6 females and 15 males) with a mean age of 48.8 (SD 13.8) years with various mobility impairments participated in this study. The touchpads received mean usability scores on the SUS 80.1 (SD 18.5) and Health-ITUES 4.23 (SD 0.67). The SUS scores reported suggest the touchpad system is "usable"; however, the Health-ITUES scores were slightly below a suggested benchmark. Participants reported moderate to high enjoyment but perceived the exertion as "somewhat easy." Self-efficacy was moderate to high and did not differ pre- to postgame play. The participants regarded the touchpads as novel, fun, and entertaining. The generalizability of our results is limited due to the heterogenous sample; however, our participants identified several areas of improvement for future iteration.

Effects of the Trp64Arg Polymorphism in the ADRB3 Gene on Body Composition, Cardiorespiratory Fitness, and Physical Activity in Healthy Adults.

The ADRB3 gene plays a role in energy expenditure by participating in lipolysis, which affects body composition and performance. The ADRB3 rs4994 polymorphism has been studied in groups of athletes, overweight individuals, and obese and diabetic patients, but it has not been studied in young and healthy adults so far. In the present study, we examined the association of ADRB3 rs4994 polymorphism with body composition, somatotype, cardiorespiratory fitness and physical activity in young, healthy adults (N = 304). All subjects had anthropometric measurements, and somatotypes were assessed using the Heath-Carter method. In addition, cardiorespiratory fitness and physical activity levels were assessed. Genotyping for the ADRB3 gene was performed using a PCR-RFLP method. In the male group, body components were associated with the Trp64Trp genotype (waist circumference (p = 0.035), hip circumference (p = 0.029), BF (%) (p = 0.008), and BF (kg) (p = 0.010), BMI (p = 0.005), WHtR (p = 0.021), and BAI (p = 0.006)). In addition, we observed that the Trp64Trp genotype was associated with somatotype components (p = 0.013). In contrast, the Arg allele was associated with the ectomorphic components (0.006). We also observed a positive impact of the Trp64Trp genotype with maximal oxygen uptake (p= 0.023) and oxygen pulse (p = 0.024). We observed a negative relationship of the Trp64Trp genotype in the female group with reported moderate-intensity exercise (p = 0.036). In conclusion, we found an association of the Trp64 allele with anthropometric traits, somatotype and parameters describing physical performance in the male group. In the female subpopulation, we only found an effect of the polymorphism Trp64Arg on the level of physical activity for moderate-intensity exercise.

Validation of the LPA-SQUASH in post-liver-transplant patients.

This study aimed to validate the revised Short Questionnaire to Assess Health-Enhancing Physical Activity (SQUASH) to measure sedentary activity in post-liver-transplant patients. The proposed scale could be useful for transplantation nurses to assess and modify sedentary lifestyles and increase physical activity. The SQUASH was modified to include items on sitting time and light-intensity physical activity (LPA-SQUASH). A pilot study was conducted with 20 liver transplant patients, and an expert panel validated the scale contents. Then, post-liver-transplant outpatients at a Japanese university hospital participated in the main study (September-October 2020), in which questionnaires were mailed twice to assess test-retest reliability, and accelerometers used to establish criterion validity. Intra-class correlation coefficients (ICC) were calculated for test-retest reliability. Spearman correlations and Bland-Altman plots were used to assess validity and measurement error. In total, 173 participants returned the questionnaires, and 106 and 71 completed the reliability and validation studies, respectively. The range of LPA-SQUASH correlation coefficients for test-retest was .49-.58. ICCs ranged from .72 to .80 for items other than leisure. Accelerometer data and the LPA-SQUASH total physical activity amount and light-intensity physical activity correlated moderately. We modified the SQUASH, which was developed to measure physical activity in healthy adults, to assess light-intensity physical activity in post-liver-transplant patients. The LPA-SQUASH showed acceptable validity and reliability. The questionnaire may be used by transplantation nurses to examine light-intensity physical activity content/duration, deliver patient education considering patients' sedentary lifestyle, and facilitate goal setting for physical activity interventions to prevent metabolic syndrome.

Electrically assisted cycling for individuals with type 2 diabetes mellitus: a pilot randomized controlled trial

BackgroundType 2 diabetes mellitus (T2DM) and its associated complications puts considerable strain on healthcare systems. With the global incidence of T2DM increasing, effective disease management is essential. Physical activity (PA) is a key component of T2DM management; however, rates of PA engagement are low in this population. Developing effective and sustainable interventions that encourage PA is a high priority. Electrically assisted bicycles are becoming increasingly popular and may increase PA in healthy adults. This study aimed to provide evidence of the feasibility of conducting a randomized controlled trial to evaluate the efficacy of an e-cycling intervention to increase PA and improve health in individuals with T2DM.MethodsA parallel-group two-arm randomized, waitlist-controlled pilot study was conducted. Individuals were randomized to either an e-bike intervention or standard care. The intervention incorporated two one-to-one e-bike skills training and behavioural counselling sessions delivered by a community-based cycling charity, followed by a 12-week e-bike loan with two further sessions with the instructors. Feasibility was assessed via measures related to recruitment, retention and intervention implementation. Post-intervention interviews with instructors and participants explored the acceptability of the study procedures and intervention. Clinical, physiological and behavioural outcomes were collected at baseline and post-intervention to evaluate the intervention’s potential.ResultsForty participants (Mage = 57) were randomized, of which 34 were recruited from primary care practices. Thirty-five participants were retained in the trial. The intervention was conducted with high fidelity (> 80% content delivered). E-bike training provided participants with the skills, knowledge and confidence needed to e-bike independently. Instructors reported being more confident delivering the skills training than behavioural counselling, despite acknowledging its importance. The study procedures were found to be acceptable to participants. Between-group differences in change during the intervention were indicative of the interventions potential for improving glucose control, health-related quality of life and cardiorespiratory fitness. Increases in overall device measured moderate-to-vigorous PA behaviour following the intervention were found, and there was evidence that this population self-selected to e-cycle at a moderate intensity.ConclusionsThe study’s recruitment, retention, acceptability and potential efficacy support the development of a definitive trial subject to identified refinements.Trial registrationISRCTN, ISRCTN67421464. Registered 17/12/2018.

Effects Of Transcranial Direct Current Stimulation On Physical Activity In Healthy Subjects: A Pilot Study

Physical activity (PA) has well-established health benefits. Current efforts to enhance PA have targeted mainly socio-economic factors. Despite these efforts, only a small number of adults engages in regular PA. Regulation of voluntary PA is linked to brain mechanisms involving the dopaminergic system. Transcranial direct current stimulation (tDCS) involves neuromodulation and can target specifically the dopaminergic system. PURPOSE: To determine if tDCS targeted to the left dorsolateral prefrontal cortex and coupled to an exercise stimulus increases overall daily PA in healthy subjects. METHODS: In a single-blinded parallel design, subjects were randomly assigned to a group undergoing Active (n = 13) (mean ± SD; age = 26.8 ± 10.2 years; 3 males, 10 females) or Sham/control (n = 9) (age = 23.3 ± 7.9 years; 2 males, 7 females) tDCS. PA was monitored using a thigh-worn activPAL micro accelerometer for 2 weeks before (PRE) and 3 weeks during (DUR) the tDCS intervention. The tDCS intervention consisted of 20 mins of tDCS (ie. active or sham), followed by brisk walking for 30 mins, 3 times a week during DUR. PA was evaluated as Total Daily Steps (TDS) and Activity Score (AS; describing PA energy expenditure in terms of metabolic equivalent (MET)). Collected data corresponding to PRE and DUR were averaged for the course of week 2 and 3, respectively. Informed consent was obtained at the time of enrollment and the research was approved by the ASU Institutional Review Board. RESULTS: ANOVA analyses found significant effects for time for TDS (P < 0.001), but not for AS (P > 0.05). Pairwise comparisons indicated no significant effects for neither TDS or AS at PRE. TDS (steps) increased in response to the tDCS, in both the Active (DUR, 7411 ± 2126 vs PRE, 6201 ± 2303; P < 0.01) and the Sham (DUR, 6840 ± 1443 vs PRE, 5778 ± 1508; P < 0.05) groups. However, TDS response was ~14% higher in the Active Group. AS (MET-hr/day) increased in response to the tDCS in the Active (DUR, 33.2 ± 0.9 vs PRE, 32.8 ± 0.9 steps; P ≤ 0.05), but not Sham (DUR, 32.8 ± 0.8 vs PRE, 32.8 ± 0.6 steps; P > 0.05) group. CONCLUSION: Three weeks of active tDCS increases measures of daily PA in healthy subjects. Although studies with larger number of subjects are needed, this study provides preliminary evidence for neurostimulation as a promising intervention to increase PA in healthy adults.

TAILORED MOBILE PHONE APP PROMOTING DAILY PHYSICAL ACTIVITY: A RANDOMIZED TRIAL

Background/Objective: Do adults better adhere to daily physical activity when they were provided a personalized program an App delivered compared to single pedometer feedback? An experimental study including randomized parallel group with or without the personalized program aimed at assessing the effect of a PA App designed to enhance daily physical activity in healthy adults.&#x0D; Methods: The participants were 30 adults (12 men and 18 women), aged between 35 and 60 years (45.33 ± 7.6). They were randomly assigned to a control group (CG, N=15), or to an experimental group (EG, N=15). Participants from the EG received their program from an app linked to a web-platform and benefited from daily walking step-count feedback, individually adapted goals per week, behavioral advices and health information. Participants from the CG only benefited of daily walking step-count on their smartphones.&#x0D; Results: The primary outcomes measures were number of walking steps per week; they were collected at baseline, week 6 and week 12. The secondary outcome was adherence based on the number of weeks the participants connected their smartphone to the web-platform.&#x0D; Non-parametric statistics indicated that (i) the EG maintained their adherence to the program more than the CG and (ii) the number of steps walked by participants from the EG increased significantly.&#x0D; Conclusion: Adults adhere better to daily physical activity when they benefit from a personalized program an app delivered.

Facilitators and barriers to fitness bootcamp participation using the Behaviour Change Wheel

Objective: Despite its importance for mental and physical health, many adults fail to meet current physical activity recommendations. Furthermore, most adults who begin a physical activity programme revert to being less active or even inactive within the first 6 months. Fitness bootcamps represent a potential intervention for improving physical activity in healthy adults. However, no study to date has examined the influences on long-term participation in fitness bootcamps, which is the first step to developing an effective intervention. Using the Behaviour Change Wheel (BCW) framework, this study identified the facilitators and barriers to long-term (1 year or more) fitness bootcamp participation, which were then linked to behaviour change techniques (BCTs) to facilitate intervention development. Design: Qualitative research design. Setting: Data collection occurred in England. Method: Interviews were conducted with 15 long-term fitness bootcamp participants. Results: Thematic analysis revealed 17 facilitators and 6 barriers to long-term fitness bootcamp participation. Participants highlighted the importance of facilitators such as convenience, being outdoors and enjoyment. The social environment, including having a positive instructor and supportive group members, was further noted as a key influence on participation. While long-term participants faced occasional barriers to their routine such as physical injury, bad weather and competing events, the impact of these could be minimised through appropriate BCTs such as ‘demonstration of the behaviour’ and ‘restructuring the social/physical environment’. Conclusion: Findings from this study highlight the importance of social and environmental factors to promoting long-term fitness bootcamp participation and the inclusion of social and physical environmental restructuring as key intervention components.

The Associations between Self-Determined Motivation, Multidimensional Self-Efficacy, and Device-Measured Physical Activity

Self-determined motivation (SDT) and self-efficacy theory have been widely used for understanding individuals’ physical activity motivation and self-efficacy. However, there is a gap of evidence on the relations between SDT and multidimensional self-efficacy with device-measured physical activity in healthy adults. Questionnaires including the behavior regulation in exercise questionnaire version 2 (BREQ-2) and the multidimensional self-efficacy for exercise scale (MSES) were completed by the participants at baseline. All participants wore an accelerometer for seven days to record their physical activities at baseline and eight-week follow up. In total, thirty healthy adults completed the study (12 men, 18 women). The results showed that intrinsic motivation and scheduling self-efficacy had significantly positive associations with moderate-to-vigorous physical activity energy expenditure and duration. Multiple regression analysis showed that the relative autonomy index, task and scheduling efficacy could predict physical activity at baseline, but no SDT or self-efficacy variable could predict physical activity behavior after eight weeks. These results showed that the associations between motivation and self-efficacy with physical activity might change within a short period of time, which suggests that the regular assessment of motivation and self-efficacy might be needed in interventional programs to promote continued physical activity participation in healthy adults.

Impact of Different Types of Physical Activity in Green Urban Space on Adult Health and Behaviors: A Systematic Review.

This systematic review aimed to investigate the type of physical activity carried out in green urban spaces by the adult population and to value its impact on the population’s health. Additionally, another purpose was to examine if the presence of outdoor gyms in green urban spaces can promote participation in physical activity among adults. Searches of electronic databases, with no time restrictions and up to June 2020, resulted in 10 studies meeting the inclusion criteria. A quantitative assessment is reported as effect size. Many people practiced walking activity as a workout, which showed improvements in health. Walking is the most popular type of training due to its easy accessibility and it not requiring equipment or special skills. Outdoor fitness equipment has been installed in an increasing number of parks and has become very popular worldwide. Further, outdoor fitness equipment provides free access to fitness training and seems to promote physical activity in healthy adults. However, other studies about outdoor fitness equipment efficiency are needed. People living near to equipped areas are more likely to perform outdoor fitness than those who live further away. The most common training programs performed in green urban spaces included exercises with free and easy access, able to promote physical health and perception.

The influence of physical activity on the nociceptive flexion reflex in healthy people.

The nociceptive flexion reflex (NFR) is a spinal reflex induced by painful stimuli resulting in an appropriate withdrawal response. The NFR is considered to be an objective physiological correlate of spinal nociception. Previous research has already demonstrated that physical activity (PA) can influence pain assessments. To date, no studies have directly examined the relationship between PA and spinal nociception. Hence, this study aimed to investigate whether the NFR threshold can be predicted by report-based and monitor-based measures of PA in healthy adults. PA and the NFR threshold of 58 healthy adults were assessed. PA was evaluated by self-report using the International Physical Activity Questionnaire and by monitor-based accelerometry data. The NFR threshold was elicited through transcutaneous electrical stimulation of the sural nerve and quantified by the biceps femoris muscle electromyogram. Hierarchical linear regression analyses were performed to determine the relationship between PA and the NFR, while controlling for confounders. Monitor-based measured step count and activities of moderate- to vigorous-intensity predicted the NFR threshold accounting for 23.0% (p=.047) to 37.1% (p=.002) of the variance. Larger amounts of step counts and higher participation in moderate- to vigorous-intensity activities predicted higher NFR thresholds. Monitor-based activities of sedentary intensity predicted the NFR threshold accounting for 35.8% (p=.014) to 35.9% (p=.014) of the variance. Spending more time per day on activities of sedentary intensity predicted lower NFR thresholds. The study provides preliminary evidence indicating that a physically active lifestyle may reduce spinal nociception in healthy adults, while a sedentary lifestyle enhances spinal nociception. The present study provides preliminary evidence that the influencing effects of physical activity on pain are the result of a strong descending control and do not purely rely on supraspinal mechanisms. These study results highlight the importance of considering physical activity levels when evaluating nociceptive processing, given the prognostic value of physical activity in spinal nociception. Furthermore, this study encourages future research to examine the effects of moderate- to vigorous-intensity exercise programmes on spinal nociception in chronic pain populations.

Effect of eHealth to increase physical activity in healthy adults over 55 years: A systematic review and meta-analysis.

To estimate the effect of eHealth interventions on increasing physical activity (PA) in healthy adults over 55years, a systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. MEDLINE, Cochrane, Web of Science, SPORTDiscus, and Scopus databases were searched, from inception to February 2020, for experimental studies reporting the effect of eHealth interventions on steps/day, daily moderate-to-vigorous physical activity (MVPA min/day), PA min/week, and MVPA min/week among adults over 55years. The DerSimonian and Laird method was used to compute a pooled effect size (ES) estimate and the respective 95% confidence interval (95% CI). Eighteen studies were included in this meta-analysis with adults whose age ranged from 58 to 74.2years. The interventions lasted between four and 52weeks. The ES estimates of eHealth interventions on increasing PA were 0.59 (95% CI: 0.15-1.02) for steps/day, 0.49 (95% CI: 0.17-0.80) for daily MVPA, 0.13 (95% CI: 0.01-0.24) for total weekly PA and 0.31 (95% CI: 0.13-0.48) for weekly MVPA. Considering clinical improvements, the mean change difference estimates were an increase of 1616.28 steps/day (95% CI: 386.25-2846.31), 7.41minutes of daily MVPA (95% CI: 3.24-11.57), 40.54minutes of total weekly PA (95% CI: -8.71 to 89.79) and 56.35minutes of weekly MVPA (95% CI: 17.43-95.27). In conclusion, eHealth interventions are effective in increasing PA levels among adults over 55years, resulting in increased steps/day, MVPA min/day, PA min/week and MVPA min/week.

The Effectiveness of the Transtheoretical Model to Improve Physical Activity in Healthy Adults: A Systematic Review

Despite the known risks of physical inactivity, only 50% of adults meet the recommended guidelines for physical activity (PA). Therefore, numerous interventions have been designed to increase PA across a lifespan. The purpose of this systematic review was to determine the effectiveness of interventions based on the transtheoretical model to improve PA in healthy adults. Electronic databases (CINAHL, MEDLINE, Psychology & Behavioral Sciences Collection, PsycINFO, Sociological Collection, and SPORTDiscus) were systematically searched from January 2001 to May 2020. A total of 11 randomized pretest-posttest studies were included in this review. Ten studies utilized a subjective measurement of PA, and 3 studies included an objective measure. Five studies demonstrated significant improvements in PA for the transtheoretical model-based intervention groups compared with control/comparison groups; however, 6 studies demonstrated no differences between groups. The findings suggest that there is inconsistent evidence to support the use of interventions based on the transtheoretical model to improve PA in adult populations. Interventions were more successful when materials were delivered via in-person counseling and when study participants were in the precontemplation or contemplation phases at baseline.

Effectiveness of Wearable Trackers on Physical Activity in Healthy Adults: Systematic Review and Meta-Analysis of Randomized Controlled Trials

BackgroundWearable trackers are an increasingly popular tool among healthy adults and are used to facilitate self-monitoring of physical activity.ObjectiveWe aimed to systematically review the effectiveness of wearable trackers for improving physical activity and weight reduction among healthy adults.MethodsThis review used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology and reporting criteria. English-language randomized controlled trials with more than 20 participants from MEDLINE, CINAHL, Cochrane Library, Web of Science, PubMed, and Scopus (2000-2017) were identified. Studies were eligible for inclusion if they reported an intervention group using wearable trackers, reporting steps per day, total moderate-to-vigorous physical activity, activity, physical activity, energy expenditure, and weight reduction.ResultsTwelve eligible studies with a total of 1693 participants met the inclusion criteria. The weighted average age was 40.7 years (95% CI 31.1-50.3), with 64.4% women. The mean intervention duration was 21.4 weeks (95% CI 6.1-36.7). The usage of wearable trackers was associated with increased physical activity (standardized mean difference 0.449, 95% CI 0.10-0.80; P=.01). In the subgroup analyses, however, wearable trackers demonstrated no clear benefit for physical activity or weight reduction.ConclusionsThese data suggest that the use of wearable trackers in healthy adults may be associated with modest short-term increases in physical activity. Further data are required to determine if a sustained benefit is associated with wearable tracker usage.

Is the 10 metre walk test on sloped surfaces associated with age and physical activity in healthy adults?

BackgroundPreferred walking speed is considered an important indicator of health in older adults and is measured on level ground. However, this may not represent the complex demands of community ambulation such as walking on sloped surfaces. Performing a 10 m walk test on a sloped surface is a novel test, and may be a more sensitive measure of walking capacity which may better discriminate age or health-related changes in gait speed compared to a traditional level 10 m walk test. The purpose of this investigation was to determine healthy adults’ performance in the 10 m walk test across various inclines and speeds, and which version of the 10 m walk test would be best at discriminating age-related changes in walking speed. Further, this study aimed to determine whether measures of general health and physical activity are associated with the performance of each test.MethodsHealthy Adults (n = 181) aged 20–80 years completed the 10 m walk test on level, downhill and uphill surfaces (8° inclination) at fastest and preferred speeds. Descriptive statistics were calculated for walking speed for males and females across each decade of life. Repeated measures ANOVA was performed to discriminate age-related changes in gait speed by decade, for the 10 m walk test at each speed and slope. Multiple linear regression analyses were conducted to examine the association between waist to height ratio, resting heart rate, age and self-reported physical activity upon preferred and fastest walking speeds at each incline (level/downhill/uphill).ResultsThe 10 m walk test best discriminated age-related changes in gait speed when performed at fastest speeds on each slope, or at a preferred speed on an uphill slope. Waist to height ratio, age and the physical activity index were all significantly associated with fastest walking speeds over each incline and preferred uphill speed. Only waist to height ratio was associated with preferred walking speed on level and downhill surfaces.ConclusionsThe 10 m walk test has the greatest ability to discriminate age- and health-related changes in gait speed when it is performed at a fastest speed on any slope, or uphill at a preferred speed. The normative data reported in this study may be used to compare the performance of the 10 m walk test to that of healthy adults at preferred and fastest speeds on sloped surfaces.

Evaluating Motivational Interviewing and Habit Formation to Enhance the Effect of Activity Trackers on Healthy Adults' Activity Levels: Randomized Intervention.

BackgroundWhile widely used and endorsed, there is limited evidence supporting the benefits of activity trackers for increasing physical activity; these devices may be more effective when combined with additional strategies that promote sustained behavior change like motivational interviewing (MI) and habit development.ObjectiveThis study aims to determine the utility of wearable activity trackers alone or in combination with these behavior change strategies for promoting improvements in active and sedentary behaviors.MethodsA sample of 91 adults (48/91 female, 53%) was randomized to receive a Fitbit Charge alone or in combination with MI and habit education for 12 weeks. Active and sedentary behaviors were assessed pre and post using research-grade activity monitors (ActiGraph and activPAL), and the development of habits surrounding the use of the trackers was assessed postintervention with the Self-Reported Habit Index. During the intervention, Fitbit wear time and activity levels were monitored with the activity trackers. Linear regression analyses were used to determine the influence of the trial on outcomes of physical activity and sedentary time. The influence of habits was examined using correlation coefficients relating habits of tracker use (wearing the tracker and checking data on the tracker and associated app) to Fitbit wear time and activity levels during the intervention and at follow-up.ResultsRegression analyses revealed no significant differences by group in any of the primary outcomes (all P>.05). However, personal characteristics, including lower baseline activity levels (beta=–.49, P=.01) and lack of previous experience with pedometers (beta=–.23, P=.03) were predictive of greater improvements in moderate and vigorous physical activity. Furthermore, for individuals with higher activity levels at the baseline, MI and habit education were more effective for maintaining these activity levels when compared with receiving a Fitbit alone (eg, small increase of ~48 steps/day, d=0.01, vs large decrease of ~1830 steps/day, d=0.95). Finally, habit development was significantly related to steps/day during (r=.30, P=.004) and following the intervention (r=.27, P=.03).ConclusionsThis study suggests that activity trackers may have beneficial effects on physical activity in healthy adults, but benefits vary based on individual factors. Furthermore, this study highlights the importance of habit development surrounding the wear and use of activity trackers and the associated software to promote increases in physical activity.Trial RegistrationClinicalTrials.gov NCT03837366; https://clinicaltrials.gov/ct2/show/NCT03837366

Physical Activity Assessment Between Consumer- and Research-Grade Accelerometers: A Comparative Study in Free-Living Conditions.

BackgroundWearable activity monitors such as Fitbit enable users to track various attributes of their physical activity (PA) over time and have the potential to be used in research to promote and measure PA behavior. However, the measurement accuracy of Fitbit in absolute free-living conditions is largely unknown.ObjectiveTo examine the measurement congruence between Fitbit Flex and ActiGraph GT3X for quantifying steps, metabolic equivalent tasks (METs), and proportion of time in sedentary activity and light-, moderate-, and vigorous-intensity PA in healthy adults in free-living conditions.MethodsA convenience sample of 19 participants (4 men and 15 women), aged 18-37 years, concurrently wore the Fitbit Flex (wrist) and ActiGraph GT3X (waist) for 1- or 2-week observation periods (n=3 and n=16, respectively) that included self-reported bouts of daily exercise. Data were examined for daily activity, averaged over 14 days and for minutes of reported exercise. Average day-level data included steps, METs, and proportion of time in different intensity levels. Minute-level data included steps, METs, and mean intensity score (0 = sedentary, 3 = vigorous) for overall reported exercise bouts (N=120) and by exercise type (walking, n=16; run or sports, n=44; cardio machine, n=20).ResultsMeasures of steps were similar between devices for average day- and minute-level observations (all P values > .05). Fitbit significantly overestimated METs for average daily activity, for overall minutes of reported exercise bouts, and for walking and run or sports exercises (mean difference 0.70, 1.80, 3.16, and 2.00 METs, respectively; all P values < .001). For average daily activity, Fitbit significantly underestimated the proportion of time in sedentary and light intensity by 20% and 34%, respectively, and overestimated time by 3% in both moderate and vigorous intensity (all P values < .001). Mean intensity scores were not different for overall minutes of exercise or for run or sports and cardio-machine exercises (all P values > .05).ConclusionsFitbit Flex provides accurate measures of steps for daily activity and minutes of reported exercise, regardless of exercise type. Although the proportion of time in different intensity levels varied between devices, examining the mean intensity score for minute-level bouts across different exercise types enabled interdevice comparisons that revealed similar measures of exercise intensity. Fitbit Flex is shown to have measurement limitations that may affect its potential utility and validity for measuring PA attributes in free-living conditions.

Moderate Physical Activity in Healthy Adults Is Associated With Cardiac Remodeling.

Cardiac mass and volumes are often elevated in athletes, but it is not known whether moderate physical activity is also associated with cardiac dilatation and hypertrophy in a healthy adult population. In total, 1096 adults (54% female, median age 39 years) without cardiovascular disease or cardiomyopathy-associated genetic variants underwent cardiac magnetic resonance imaging to determine biventricular volumes and function. Physical activity was assessed using a validated activity questionnaire. The relationship between cardiac parameters and activity was assessed using multiple linear regression adjusting for age, sex, race, and systolic blood pressure. Logistic regression was performed to determine the effect of activity on the likelihood of subjects having cardiac dilatation or hypertrophy according to standard cardiac magnetic resonance normal ranges. Increasing physical activity was associated with greater left ventricular (LV) mass (β=0.23; P<0.0001) and elevated LV and right ventricular volumes (LV: β=0.26, P<0.0001; right ventricular: β=0.26, P<0.0001). Physical activity had a larger effect on cardiac parameters than systolic blood pressure (0.06≤β≤0.21) and a similar effect to age (-0.20≤β≤-0.31). Increasing physical activity was a risk factor for meeting imaging criteria for LV hypertrophy (adjusted odds ratio 2.1; P<0.0001), LV dilatation (adjusted odds ratio 2.2; P<0.0001), and right ventricular dilatation (adjusted odds ratio 2.2; P<0.0001). Exercise-related cardiac remodeling is not confined to athletes, and there is a risk of overdiagnosing cardiac dilatation or hypertrophy in a proportion of active, healthy adults.

The influence of social-cognitive constructs and personality traits on physical activity in healthy adults

The psychosocial factors involved in successful physical activity engagement are not fully understood. Research suggests that specific personality traits (e.g. extraversion, conscientiousness, and neuroticism) influence physical activity behaviour. There is also evidence that social-cognitive constructs (e.g. self-efficacy, self-regulation, outcome expectations, social support, and perceived barriers) can significantly explain and predict physical activity behaviour. The current study aimed to investigate the influence of personality and social-cognitive constructs on physical activity over a 2-week period. The study employed a prospective design in which 94 participants provided 2-weeks of pedometer data and completed daily diary measures of non-ambulatory physical activity. In addition, all participants completed self-report measures of the Big Five personality traits and social-cognitive constructs. Multiple regression analyses revealed that social-cognitive constructs significantly explained 35.6% of the variance in physical activity, with goal setting emerging as a key predictor. Although personality did not have an effect on physical activity overall, subsequent analyses found significant differences in neuroticism between activity groups, and personality significantly interacted with social-cognitive constructs to influence behaviour. The findings suggest a key role for goal setting, barrier self-efficacy, conscientiousness, and neuroticism in explaining physical activity behaviour.

Comment on: "impact and cost-effectiveness of a universal strategy to promote physical activity in primary care".

The paper by Gulliford et al. [1] analyzes the cost-effectiveness of promoting physical activity in healthy adults in a UK primary care setting by a Markov state transition model. The intervention consists of annual screening for physical activity plus brief consultation through a family physician. The model assumes low intervention costs (£35 per person year) and significant added health benefits in terms of sedentary adults becoming active after 1 year. The number needed to treat for one additional sedentary adult to meet internationally recommended levels of activity is 12 (95 % confidence interval 7–33) [5]. Yet, the intervention was not found to be clearly cost-effective at a willingness to pay of £30,000 per quality-adjusted life year (QALY) gained. That is, the probability of being cost-effective was only 72 % over 10 years (Table 4). The result is surprising as effective low-cost interventions such as generic drugs or vaccines are usually highly cost-effective. On closer scrutiny, the underlying reason for the lack of cost-effectiveness is not the base-case costeffectiveness ratio (which is £13,685/QALY = 80.744/ 0.0059, based on data in Table 4) but an astonishing 29 % probability that the intervention leads to lower (!) life expectancy (Table 3). This finding, however, is at odds with the prevailing viewpoint in the literature that the relationship between the level of exercise and health/survival is linear or curvilinear [2, 3]. For example, a recently conducted large pooled cohort analysis [4] comprising 654,827 individuals, 21–90 years of age, showed that even a low level of leisure time physical activity of moderate to vigorous intensity was associated with reduced risk of mortality relative to no such activity. The overall dose– response relationship was curvilinear, with diminishing returns at high activity levels (see Fig. 1). Yet, for none of risk groups considered the returns to exercise were negative, even at the limits of the 95 % confidence interval. Therefore, the result of the analysis by Gulliford et al. [1] is not externally valid. Fig. 1 Leisure time physical activity level and hazard ratios for mortality and gains in life expectancy after age 40 [4]