Increasing dietary calcium intake of children and their parents: a randomised controlled trial.

OBJECTIVE: Approximately 25 % of Canadian children aged 4-8 years fail to meet the recommended dietary allowance (RDA) of calcium (Ca). Young children's food choices are primarily determined by their parents. No interventions have directly targeted parents as a medium through which to increase children's Ca consumption. This study compared the effectiveness of a Ca-specific intervention targeted towards parents, with generic dietary advice on the Ca consumption of children aged 4-10 years. DESIGN: A parallel two-arm randomised controlled trial was conducted. SETTING: The study was conducted across Canada. Both conditions received information on the RDA of Ca and an index of intake requirements. Material sent to the intervention condition included behavioural strategies to increase dietary Ca consumption, information on the benefits of dietary Ca intake and messages addressing perceived barriers to the consumption of Ca-rich foods. PARTICIPANTS: A total of 239 parents (93 % mothers) of children aged 4-10 years who consumed less than the RDA of Ca were randomly assigned in a 1:1 allocation ratio. RESULTS: There was a significant increase in total Ca intake and Ca from dairy for children at weeks 8, 34 and 52 (P ≤ 0·001) in both conditions. Parental Ca intake and amount spent on dairy products did not significantly increase following the intervention. CONCLUSIONS: Provision of daily Ca requirements with regular reminders could impact parents' delivery of Ca-rich foods to their children. This finding is important for public health messaging as it suggests that parents are a potent medium through which to promote Ca intake in children.

Evaluation of a community-based, family focused healthy weights initiative using the RE-AIM framework.

BACKGROUND: Childhood overweight and obesity is a major public health concern. Community-based interventions have the potential to reach caregivers and children. However, the overall health impact of these programs is rarely comprehensively assessed. This study evaluated a physical activity and healthy eating family program (Healthy Together; HT) using the RE-AIM framework. METHODS: Ten sites implemented the 5-week program. Thirty-nine staff members and 277 program participants (126 caregivers [M age = 35.6] and 151 children [M age = 13]) participated in the evaluation. Each RE-AIM dimension was assessed independently using a mixed-methods approach. Sources of data included archival records, interviews and surveys. Effectiveness outcome variables were assessed at pre- and post-intervention and 6-month follow-up. RESULTS: Reach: HT participants were almost entirely recruited from existing programs within sites. Effectiveness: Caregivers' nutrition related efficacy beliefs increased following HT (ps < .03). Participation in HT was not associated with significant changes in physical activity or nutrition behaviour or perceived social support (ps > .05). Knowledge surrounding healthy diets and physical activity increased in children and caregivers (ps < .05). Adoption: Thirty-five percent of sites approached to implement HT expressed interest. The 10 sites selected recruited existing staff members to implement HT. IMPLEMENTATION: Program objectives were met 72.8% of the time and 71 adaptations were made. HT was finance- and time-dependent. Maintenance: Two sites fully implemented HT in the follow-up year and 5 sites incorporated aspects of HT into other programs. CONCLUSIONS: Working alongside organizations that develop community programs to conduct comprehensive, arms-length evaluations can systematically highlight areas of success and challenges. Overall HT represents a feasible community-based intervention; however further support is required in order to ensure the program is effective at positively targeting the desired outcomes. As a result of this evaluation, modifications are currently being implemented to HT.

Health benefits of electrically-assisted cycling: a systematic review.

BACKGROUND: Electrically assisted bicycles (e-bikes) have been highlighted as a method of active travel that could overcome some of the commonly reported barriers to cycle commuting. The objective of this systematic review was to assess the health benefits associated with e-cycling. METHOD: A systematic literature review of studies examining physical activity, cardiorespiratory, metabolic and psychological outcomes associated with e-cycling. Where possible these outcomes were compared to those from conventional cycling and walking. Seven electronic databases, clinical trial registers, grey literature and reference lists were searched up to November 2017. Hand searching occurred until June 2018. Experimental or observational studies examining the impact of e-cycling on physical activity and/or health outcomes of interest were included. E-bikes used must have pedals and require pedalling for electric assistance to be provided. RESULTS: Seventeen studies (11 acute experiments, 6 longitudinal interventions) were identified involving a total of 300 participants. There was moderate evidence that e-cycling provided physical activity of at least moderate intensity, which was lower than the intensity elicited during conventional cycling, but higher than that during walking. There was also moderate evidence that e-cycling can improve cardiorespiratory fitness in physically inactive individuals. Evidence of the impact of e-cycling on metabolic and psychological health outcomes was inconclusive. Longitudinal evidence was compromised by weak study design and quality. CONCLUSION: E-cycling can contribute to meeting physical activity recommendations and increasing physical fitness. As such, e-bikes offer a potential alternative to conventional cycling. Future research should examine the long-term health impacts of e-cycling using rigorous research designs.

Targeted Messages Increase Dairy Consumption in Adults: a Randomized Controlled Trial.

BACKGROUND: Dairy consumption amongst North Americans aged 30-50 has been declining. Targeted messages have been identified as a cost-efficient method through which to increase health-enhancing behavior, such as dairy intake. PURPOSE: The aim of this study is to assess the utility of targeted, framed, efficacy-enhancing messages on calcium consumption from dairy in adults aged 30-50 in a randomized controlled trial. METHOD: Seven hundred and thirty-two individuals (463 women, 269 men; M age = 40.57 years) were randomly assigned to one of five message conditions: (1) gain-framed (GF), (2) loss-framed (LF), (3) self-regulatory efficacy-enhancing (SRE), (4) GF plus SRE (GF + SRE), or (5) LF plus SRE (LF + SRE). Conditions were separate for men and women. Each condition received an emailed message on four consecutive days. Calcium intake from dairy, self-regulatory efficacy, outcome expectations, and outcome value were measured at baseline, 1 and 4 weeks following the intervention. RESULTS: Calcium intake from dairy significantly increased from baseline to week 1 post-intervention in all conditions (p < .001). A significant message condition x time interaction (p = .04) revealed that increases seen in the LF + SRE condition were maintained at week 4. All social cognitive constructs increased following the intervention (ps < .01). Self-regulatory efficacy (ß = .28, p < .01) and outcome expectations (ß = .19, p < .01) were significant predictors of subsequent calcium intake (week 4) from dairy. CONCLUSION: Taken together, it appears as though ensuring message content is targeted to the specific population's beliefs and motives is of importance when developing behavioral change intervention material.

Strategies for public health initiatives targeting dairy consumption in young children: a qualitative formative investigation of parent perceptions.

OBJECTIVE: Dairy products contain essential nutrients to ensure healthy growth and bone development in children. However, a significant proportion of children in developed countries fail to consume the daily recommended intake of dairy products. Parents are the gatekeepers of familial nutritional intake and represent a potential vehicle through which to increase dairy consumption in children. As such, formative research was conducted to gain insight into parents' perceived barriers to and benefits of purchasing and consuming dairy products and to develop innovative message content that could be utilized in future public health campaigns. DESIGN: Seven in-depth group interviews were conducted in two phases between February and May 2015. SETTING: Interviews were conducted in local recreational centres and libraries in British Columbia, Canada. SUBJECTS: Mothers (n 21, mean age 38 (sd 5) years) and fathers (n 9, mean age 38 (sd 3) years) of children aged 4-10 years. RESULTS: Parents perceived both positive and negative physical outcomes associated with consuming dairy. Lack of trustworthy information was a frequently discussed barrier theme to purchasing and consuming dairy products. Mothers were concerned about the cost of dairy products. Differences in purchasing and consumption strategies were reported between parents of children who consumed adequate dairy and those who did not. Parents believed the most appropriate communication channel was through print material. CONCLUSIONS: Messages targeting parents, as a means of increasing dairy consumption in children, should address barriers identified by parents. In addition, practical tips should be provided to promote purchasing and consumption of dairy products.

A systematic review of behavioural interventions to increase maternal calcium intake.

Pregnancy and lactation are a time when adequate calcium consumption is essential for the development of the fetus and to ensure the health of the mother. Over 50% of Canadian women of childbearing and rearing age fail to meet the recommended daily intake of calcium. Identification of effective behavioural intervention strategies for increasing calcium intake is needed within this specific population. This paper brings together all published behavioural interventions designed to increase calcium consumption in pregnant, lactating or post-partum mothers in a systematic review. Relevant studies were obtained through searches of MEDLINE, EMBASE, PsycINFO, CINAHL and the Cochrane Library with no date restrictions. Studies were evaluated using previously published criteria for evaluating calcium behaviour change interventions. This systematic literature review identified five behavioural calcium interventions conducted within this population. Three interventions aimed to improve overall dietary behaviours, the fourth aimed to promote breastfeeding (including increasing calcium consumption) and the fifth aimed to increase daily servings of yoghurt. Only one of the five interventions yielded large effect sizes, with a mean change of 954 mg of calcium per day post-intervention. The number of behavioural change techniques did not appear to be related to intervention efficacy. Only one study used a theoretical framework to guide the intervention. This review highlights the lack of research examining behaviour change interventions aimed at increasing calcium consumption in pregnant, lactating and post-partum women and provides practical suggestions for researchers wishing to intervene with this population in the future.

''I felt marvellous e-cycling. If I had long hair I would have flicked it": a qualitative investigation of the factors associated with e-cycling engagement among adults with type 2 diabetes.

Background: Physical activity (PA) is a key component in the management of type 2 diabetes. However, this population have low rates of PA engagement. Electrically assisted cycling has been identified as a means through which to increase PA by incorporating activity into daily life, while overcoming some of the barriers to conventional cycling. The determinants of e-cycling among people living with chronic disease are largely unknown. The aim of this research was to explore the determinants of e-cycling among individuals with type 2 diabetes using the Theoretical Domains Framework (TDF) and the Capability, Opportunity and Motivation for Behaviour change model (COM-B). This information is important for determining the suitability of future e-cycling initiatives and, if appropriate, inform future e-cycling interventions. Method: One-to-one semi structured interviews were conducted with 16 participants from the e-cycling arm of a pilot randomised controlled trial between September 2019 and April 2020. The TDF was used to develop the interview guide. The framework method of analysis was used, incorporating both deductive and inductive reasoning. A conceptual model of the factors that influence e-cycling in this population was created. Results: The most commonly reported TDF domains were skills, knowledge, belief about capabilities, belief about consequences and environmental context and resources. Specifically, e-bike training facilitated e-cycling engagement by providing participants with the skills, knowledge, and confidence needed to ride the e-bike and ride on the road. In addition, the enjoyment of e-cycling was a key facilitator to engagement. Participants engaged in e-cycling to improve their health rather than for environmental reasons. Most barriers to e-cycling related to the natural or physical environment. Conclusion: This study provides insight into the personal, social, and environmental factors associated with e-cycling in this population. The findings of this study can be used to develop a more refined e-cycling intervention targeting the factors identified as influencing e-cycling engagement. In addition, this information will help in the selection of mechanistic outcome measures for evaluation.

Study protocol for two pilot randomised controlled trials aimed at increasing physical activity using electrically assisted bicycles to enhance prostate or breast cancer survival.

BACKGROUND: In 2020, 1.4 and 2.3 million new cases of prostate cancer and breast cancer respectively were diagnosed globally. In the UK, prostate cancer is the most common male cancer, while breast cancer is the most common female cancer. Engaging in physical activity (PA) is a key component of treatment. However, rates of PA are low in these clinical populations. This paper describes the protocol of CRANK-P and CRANK-B, two pilot randomised controlled trials, involving an e-cycling intervention aimed at increasing PA in individuals with prostate cancer or breast cancer respectively. METHODS: These two trials are single-centre, stratified, parallel-group, two-arm randomised waitlist-controlled pilot trials in which forty individuals with prostate cancer (CRANK-P) and forty individuals with breast cancer (CRANK-B) will be randomly assigned, in a 1:1 allocation ratio, to an e-cycling intervention or waitlist control. The intervention consists of e-bike training with a certified cycle instructor, followed by the provision of an e-bike for 12 weeks. Following the intervention period, participants in the e-bike condition will be directed to community-based initiatives through which they can access an e-bike. Data will be collected at baseline (T0), immediately post intervention (T1) and at 3-month follow-up (T2). In addition, in the intervention group, data will be collected during the intervention and follow-up periods. Quantitative and qualitative methods will be used. The primary objectives are to determine effective recruitment strategies, establish recruitment and consent rates, adherence and retention in the study, and determine the feasibility and acceptability of the study procedures and intervention. The potential impact of the intervention on clinical, physiological and behavioural outcomes will be assessed to examine intervention promise. Data analyses will be descriptive. DISCUSSION: The findings from these trials will provide information on trial feasibility and highlight the potential of e-cycling as a strategy to positively impact the health and behaviour of individuals with prostate cancer and breast cancer. If appropriate, this information can be used to design and deliver a fully powered definitive trial. TRIAL REGISTRATION: CRANK-B: [ISRCTN39112034]. CRANK-P [ISRCTN42852156]. Registered [08/04/2022] https://www.isrctn.com .

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

BACKGROUND: Type 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. METHODS: A 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. RESULTS: Forty 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. CONCLUSIONS: The study's recruitment, retention, acceptability and potential efficacy support the development of a definitive trial subject to identified refinements. TRIAL REGISTRATION: ISRCTN, ISRCTN67421464 . Registered 17/12/2018.

A Pilot Study on In-Task Affect Predicting Free-Living Adherence to HIIT and MICT.

Purpose: To report pilot test findings on whether in-task affect during a supervised exercise program, where participants were randomized to either moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT), predicts changes in moderate-to-vigorous physical activity (MVPA-Total and MVPA10+ in bouts of ≥ 10 min) at 1- and 6-month post-intervention. Method: This experimental study design randomized 32 inactive adults with prediabetes to complete a 2-week supervised MICT or HIIT plus behavioral counseling exercise intervention and objectively assessed free-living physical activity post-intervention. The Feeling Scale (FS) was used to assess the in-task effect. FS was measured in the middle of four, 1-min intervals in the HIIT condition, corresponding to ~20%, ~50%, ~75%, and ~85% of work out time. For the MICT condition, FS was assessed at similar exercise duration percentage times as HIIT. Accelerometer data evaluated MVPA at 1- and 6-month post-intervention. Results: 32 adults were included in the analyses. Pilot findings indicated in-task affect between the conditions did not predict changes in MVPA-Total from baseline to 1 and 6 months. For MVPA10+, in-task affect negatively predicted MVPA10+ over time in the MICT condition only. Conclusion: This study provides preliminary evidence that affect during MICT negatively predicts MVPA10+ over time, and that there is no difference of in-task affect's utility in predicting MVPA-Total between HIIT and MICT. Larger studies are required to confirm these findings.

Using the behavior change wheel to develop text messages to promote diet and physical activity adherence following a diabetes prevention program.

Improving diet and physical activity (PA) can reduce the risk of developing type 2 diabetes (T2D); however, long-term diet and PA adherence is poor. To impact population-level T2D risk, scalable interventions facilitating behavior change adherence are needed. Text messaging interventions supplementing behavior change interventions can positively influence health behaviors including diet and PA. The Behavior Change Wheel (BCW) provides structure to intervention design and has been used extensively in health behavior change interventions. Describe the development process of a bank of text messages targeting dietary and PA adherence following a diabetes prevention program using the BCW. The BCW was used to select the target behavior, barriers and facilitators to engaging in the behavior, and associated behavior change techniques (BCTs). Messages were written to map onto BCTs and were subsequently coded for BCT fidelity. The target behaviors were adherence to diet and PA recommendations. A total of 16 barriers/facilitators and 28 BCTs were selected for inclusion in the messages. One hundred and twenty-four messages were written based on selected BCTs. Following the fidelity check a total of 43 unique BCTs were present in the final bank of messages. This study demonstrates the application of the BCW to guide the development of a bank of text messages for individuals with prediabetes. Results underscore the potential utility of having independent coders for an unbiased expert evaluation of what active components are in use. Future research is needed to demonstrate the feasibility and effectiveness of resulting bank of messages.

Making changes to one's physical activity and diet can reduce future risk of developing type 2 diabetes. That being said, making life-long changes to complex behaviors such as diet or physical activity is easier said than done. Text messages can be used to improve long-term diet and physical activity changes; however, it can be difficult to identify what should be said in a text message to nudge those behaviors. To improve utility and reduce cost of sending unnecessary messages, theory should be used in developing text messaging content. The current study used the Behavior Change Wheel to develop a library of text messages that can be used to improve diet and physical activity in individuals who have taken part in an effective community-based diabetes prevention program. The Behavior Change Wheel guides researchers to develop real-world interventions based on evidence and theory. Overall, we created a library of 124 theory-based messages which can be further tested following a diabetes prevention program.

Mapping behavior change techniques to characterize a social cognitive theory informed physical activity intervention for adults at risk of type 2 diabetes mellitus.

Behavior change techniques (BCTs) are used to target theoretical mechanisms of action predicted to bring about behavior change. Reporting BCTs and connecting them to mechanisms of action is critical to understanding intervention processes of change. This article identifies the BCTs associated with an exercise intervention for individuals at risk of type 2 diabetes and determines the extent to which these BCTs target associated mechanisms of action. BCTs were mapped onto social cognitive theory (SCT) and the theoretical domains framework (TDF) using published literature identifying links between BCTs and SCT/TDF and expert consensus. Two coders then used the 93-item BCT taxonomy (BCTTv1) to independently code BCTs within the intervention. The BCTs used in the current intervention enabled identification of the theoretical mechanisms of action targeted in the intervention. More than 70% of the intervention content incorporated at least one BCT. More than 50% of the BCTs used targeted SCT constructs and more than 70% of BCTs used targeted at least one of the 14 TDF domains. Five BCTs did not map onto either SCT or TDF. This research provides a systematic method of linking BCTs to mechanisms of action. This process increases the transparency of intervention content and identification of the mechanisms of action targeted in the current intervention. Reporting interventions in this manner will enable the most potent mechanisms of actions associated with long-term behavior change to be identified and utilized in future work. Trial Registration: ClinicalTrials.gov # NCT02164474. Registered on June 12, 2014.

The impact of e-cycling on travel behaviour: A scoping review.

INTRODUCTION: Electrically assisted bicycles (e-bikes) have become increasingly popular in the past decade. This review aimed to scope the literature to identify what is known about the frequency and duration of e-bike use, their impact on travel behaviour, the purposes for which e-bikes are used and factors associated with e-bike use. In addition, the review aimed to identify gaps in the literature and highlight future research priorities. METHODS: A scoping review of published and unpublished literature in any language. Relevant articles were identified through searching six databases, two grey literature platforms and reference lists. Searches were conducted until August 2019. Data were extracted using a standardised extraction form and descriptive and narrative results are provided. RESULTS: Seventy-six studies met the inclusion criteria. The volume of research has increased since 2017 and primarily examines personal e-bike use, as opposed to e-bike share/rental schemes or organizational e-bike initiatives. The use of e-bikes increased the frequency and duration of cycling compared to conventional cycling and may help overcome barriers associated with conventional cycling. The uptake in e-cycling largely substitutes for conventional cycling or private car journeys, though the degree of substitution depends on the primary transport mode prior to e-bike acquisition. E-bikes are primarily used for utilitarian reasons, though older adults also engage in recreational e-cycling. Research priorities include quantitatively examining e-bike use, their impact on overall transport behaviour and identifying determinants of e-cycling to inform intervention and policy. CONCLUSIONS: This review suggests that the personal use of e-bikes is associated with a reduction in motorized vehicle use, which has potential positive impacts on the environment and health. The impacts of e-bike share schemes and workplace initiatives are less well understood. Evidence describing the purposes for which e-bikes are used, and the factors associated with usage, are useful to inform e-cycling promotion policy.

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

BACKGROUND: The global incidence of type 2 diabetes mellitus (T2DM) is increasing. Given the many complications associated with T2DM, effective management of the disease is crucial. Physical activity is considered to be a key component of T2DM management. However, people with T2DM are generally less physically active than individuals without T2DM and adherence to physical activity is often poor following completion of lifestyle interventions. As such, developing interventions that foster sustainable physical activity is of high priority. Electrically assisted bicycles (e-bikes) have been highlighted as a potential strategy for promoting physical activity in this population. E-bikes provide electrical assistance to the rider only when pedalling and could overcome commonly reported barriers to regular cycling. This paper describes the protocol of the PEDAL-2 pilot randomized controlled trial, an e-cycling intervention aimed at increasing physical activity in individuals with T2DM. METHODS: A parallel-group two-arm randomized waitlist-controlled pilot trial will be conducted. Forty individuals with T2DM will be randomly assigned, in a 1:1 allocation ratio, to an e-cycling intervention or waitlist control. Recruitment and screening will close once 20 participants have been randomized to each study arm. The intervention will involve e-bike training with a certified cycle instructor and provision of an e-bike for 12 weeks. Data will be collected at baseline, during the intervention and immediately post-intervention using both quantitative and qualitative methods. In this trial, the primary interests are determination of effective recruitment strategies, recruitment and consent rates, adherence and retention and delivery and receipt of the intervention. The potential impact of the intervention on a range of clinical, physiological and behaviour outcomes will be assessed to examine intervention promise. Data analyses will be descriptive. DISCUSSION: This paper describes the protocol for the PEDAL-2 pilot randomized controlled trial. Results from this trial will provide information on trial feasibility and identify the promise of e-cycling as a strategy to positively impact the health and behaviour of individuals with T2DM. If appropriate, this information can be used to design and deliver a fully powered definitive trial. TRIAL REGISTRATION: ISRCTN, ISRCTN67421464. Registered 03/01/2019.

Brief Exercise Counseling and High-Intensity Interval Training on Physical Activity Adherence and Cardiometabolic Health in Individuals at Risk of Type 2 Diabetes: Protocol for a Randomized Controlled Trial.

BACKGROUND: Worldwide incidence of type 2 diabetes (T2D) is rapidly increasing. Given the numerous negative health consequences associated with T2D, prevention of this disease has become a priority. Lifestyle changes, including regular exercise, can reduce the onset of T2D in those at elevated risk. However, long-term adherence to exercise is often poor in this population. Existing lifestyle interventions targeting exercise are labor intensive and costly for staff and participants. Evidence-informed counseling delivered in a manner that reduces dependence on staff and facilitates self-regulatory skills could alleviate time and financial barriers while promoting independent exercise. OBJECTIVE: This protocol outlines the design, recruitment, and proposed analysis of a brief, 2-week evidence-informed exercise counseling intervention combined with either high-intensity interval training (HIIT) or traditional moderate-intensity continuous training (MICT). METHODS: Small Steps for Big Changes is a 2-arm randomized controlled trial that will examine the effectiveness of combining brief exercise counseling with HIIT or MICT on adherence to moderate and vigorous exercise over 1 year. Cardiorespiratory fitness will be assessed at baseline, post intervention (2 weeks), and at 6- and 12-month follow-up. Physical activity behavior will be examined at baseline, post intervention, and 3-, 6-, 9-, and 12-month follow-up. The impact of the intervention on psychosocial outcomes pertinent to exercise adherence will be examined. RESULTS: Data collection was complete in March 2017. Data analysis is currently underway, and the first results are expected to be submitted for publication in 2019. CONCLUSIONS: The results of this brief intervention have the potential to inform future public health efforts designed to increase exercise in individuals at risk of T2D. TRIAL REGISTRATION: ClinicalTrials.gov NCT02164474; https://clinicaltrials.gov/ct2/show/NCT02164474 (Archived by WebCite at http://www.webcitation.org/74Hx1ipj6). INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/11226.

The influence of high-intensity interval training and moderate-intensity continuous training on sedentary time in overweight and obese adults.

High-intensity interval training (HIIT) elicits health benefits but it is unclear how HIIT impacts sedentary behaviour. In this preliminary study, we compared the effects of supervised HIIT or moderate-intensity continuous training (MICT) on sedentary time in overweight/obese adults. In both groups, percentage of time spent in sedentary activities was significantly reduced during the supervised exercise intervention (time main effect, P = 0.03), suggesting that both HIIT and MICT replaced time spent previously being sedentary.

High-Intensity Interval or Continuous Moderate Exercise: A 24-Week Pilot Trial.

PURPOSE: High-intensity interval training (HIIT) may lead to superior cardiometabolic improvements when compared with moderate-intensity continuous training (MICT). However, adherence to HIIT requires examination. The purpose of this pilot study was to examine moderate-to-vigorous physical activity (MVPA) adherence 24 wk after a brief counseling intervention combined with either HIIT or MICT. METHODS: Individuals at high risk of type 2 diabetes (T2D) were randomized to HIIT (n = 15) or MICT (n = 17) and completed 10 exercise sessions accompanied by a brief 10-min counseling intervention over a 2-wk period. Objectively measured purposeful MVPA (accelerometry) and cardiorespiratory fitness (V˙O2peak) were assessed at baseline and 24 wk postintervention. Self-regulatory efficacy and task self-efficacy were examined at baseline, postintervention, and 24 wk postintervention. Using an intention-to-treat analysis, change scores were calculated for HIIT and MICT and compared between groups. RESULTS: Individuals assigned to HIIT increased their MVPA by 53 min (Cohen's d = 1.52) at 24 wk compared with 19 min in MICT. Both HIIT and MICT increased relative V˙O2peak by 2 and 1 mL·kg·min, respectively. Participants in both groups increased in their self-regulatory and task self-efficacy postintervention, but both groups demonstrated similar decline at 24 wk. CONCLUSION: This pilot intervention was successful in increasing, and maintaining, free-living MVPA over a 24-wk period in individuals at high risk of T2D. Speculation that HIIT is inappropriate or unattainable for overweight individuals at high risk of T2D may be unfounded.

High-intensity interval training as an efficacious alternative to moderate-intensity continuous training for adults with prediabetes.

AIMS: High-intensity interval training (HIIT) leads to improvements in various markers of cardiometabolic health but adherence to HIIT following a supervised laboratory intervention has yet to be tested. We compared self-report and objective measures of physical activity after one month of independent exercise in individuals with prediabetes who were randomized to HIIT (n = 15) or traditional moderate-intensity continuous training (MICT, n = 17). METHOD: After completing 10 sessions of supervised training participants were asked to perform HIIT or MICT three times per week for four weeks. RESULTS: Individuals in HIIT (89 ± 11%) adhered to their prescribed protocol to a greater extent than individuals in MICT (71 ± 31%) as determined by training logs completed over one-month follow-up (P = 0.05, Cohen's d = 0.75). Minutes spent in vigorous physical activity per week measured by accelerometer were higher in HIIT (24 ± 18) as compared to MICT (11 ± 10) at one-month follow-up (P = 0.049, Cohen's d = 0.92). Cardiorespiratory fitness and systolic blood pressure assessed at one-month follow-up were equally improved (P's < 0.05). CONCLUSIONS: This study provides preliminary evidence that individuals with prediabetes can adhere to HIIT over the short-term and do so at a level that is greater than MICT.

Short-term high-intensity interval and moderate-intensity continuous training reduce leukocyte TLR4 in inactive adults at elevated risk of type 2 diabetes.

Exercise can have anti-inflammatory effects in obesity, but the optimal type and intensity of exercise are not clear. This study compared short-term high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) in terms of improvement in cardiorespiratory fitness, markers of inflammation, and glucose control in previously inactive adults at elevated risk of developing type 2 diabetes. Thirty-nine inactive, overweight/obese adults (32 women) were randomly assigned to 10 sessions over 2 wk of progressive HIIT (n = 20, four to ten 1-min sessions at ∼90% peak heart rate, 1-min rest periods) or MICT (n = 19, 20-50 min at ∼65% peak heart rate). Before and 3 days after training, participants performed a peak O2 uptake test, and fasting blood samples were obtained. Both HIIT (1.8 ± 0.4 vs. 1.9 ± 0.4 l/min, pre vs. post) and MICT (1.8 ± 0.5 vs. 1.9 ± 0.5 l/min, pre vs. post) improved peak O2 uptake (P < 0.001) and lowered plasma fructosamine (P < 0.05). Toll-like receptor (TLR) 4 (TLR4) expression was reduced on lymphocytes and monocytes after both HIIT and MICT (P < 0.05) and on neutrophils after MICT (P < 0.01). TLR2 on lymphocytes was reduced after HIIT and MICT (P < 0.05). Plasma inflammatory cytokines were unchanged after training in both groups, but MICT led to a reduction in fasting plasma glucose (P < 0.05, 5.9 ± 1.0 vs. 5.6 ± 1.0 mmol/l, pre vs. post). Ten days of either HIIT or MICT can improve cardiorespiratory fitness and glucose control and lead to reductions in TLR2 and TLR4 expression. MICT, which involved a longer duration of exercise, may be superior for reducing fasting glucose.

Where does HIT fit? An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum.

Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI), the affective response to continuous vigorous-intensity exercise (CVI) has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT), is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (W peak). Three subsequent visits involved a single bout of a) HIT, corresponding to 1-minute at ∼ 100% W peak and 1-minute at ∼ 20% W peak for 20 minutes, b) CMI, corresponding to ∼ 40% W peak for 40 minutes, and c) CVI, corresponding to ∼ 80% W peak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise.