Ronald C Plotnikoff

• PhD
• Managing Director at University of Newcastle Australia

Background: Type 2 diabetes is a major cause of illness and disability and physical activity reduces these risks. The SMART Health study aim was to compare the efficacy of a multicomponent intervention to promote aerobic physical activity and resistance training in schoolteachers at risk of or diagnosed with type 2 diabetes, with and without a tec...

Introduction Several barriers can preclude people with type 2 diabetes (T2D) from in-person exercise session participation. Telehealth may be an alternative mode of service delivery to increase uptake. We evaluated the feasibility, safety and preliminary efficacy of delivering group exercise via telehealth for people with T2D. Methods Sixteen peop...

Objective To perform a systematic review of completion rates of cardiac rehabilitation (CR) in adults aged 18 to 50 yr and describe how core components were reported, measured, and tailored to those under 50 yr. Review Methods Database search of MEDLINE, Embase, Emcare, PsycINFO, CINAHL, Scopus, and the Cochrane Library based on keywords, includin...

Background In this paper we outline the protocol for an implementation-effectiveness trial of ecofit, a multi-component mHealth intervention aimed at increasing participation in resistance and aerobic physical activity using the outdoor built environment (i.e., outdoor gyms) and social support. We have previously demonstrated the efficacy and effec...

Introduction The relationship between intervention engagement and behaviour change may vary depending on the specific engagement metric being examined. To counter this composite engagement measures may provide a deeper understanding of the relationship between engagement and behaviour change, though few studies have applied such multidimensional en...

Background: Few mobile health resistance-based physical activity interventions have targeted community-dwelling adults. "Ecofit" is a multicomponent intervention that promotes resistance and aerobic activities using smartphone technology, outdoor gyms, and social support. This study evaluated process evaluation outcomes of the ecofit randomized co...

Objective: Action planning is a common approach used in physical activity interventions. The aim of this study was to assess the association of frequency, consistency and content of action planning with physical activity behaviour, intention strength and habit strength. Methods and measures: Within a 3-month web-based, computer-tailored physical...

Purpose: The aim was to increase cardiac rehabilitation (CR) uptake using a novel intervention, Rehabilitation Support Via Postcard (RSVP), among patients with acute myocardial infarction discharged from two major hospitals in Hunter New England Local Health District (HNELHD), New South Wales, Australia. Methods: The RSVP trial was evaluated usi...

Background To examine associations between user engagement and activity-sleep patterns in a 12-week m-health behavioural intervention targeting physical activity and sleep. Methods This secondary analysis used data pooled from two Randomised Control Trials (RCT, [Synergy and Refresh]) that aimed to improve physical activity and sleep (PAS) among p...

Introduction: In Australia, 45% of adults meet the aerobic recommendations, and only 9%-30% meet the resistance training guidelines. Given the lack of at-scale community-based interventions promoting resistance training, the aim of this study was to assess the impact of an innovative mHealth intervention on upper- and lower-body muscular fitness,...

Background Whole-of-school programs have demonstrated success in improving student physical activity levels, but few have progressed beyond efficacy testing to implementation at-scale. The purpose of our study was to evaluate the scale-up of the ‘Internet-based Professional Learning to help teachers promote Activity in Youth’ (iPLAY) intervention i...

Background Mobile app-based interventions have the potential for wide-reach and therefore may be a useful tool in up-scaling physical activity interventions. In larger-scale interventions, face-to-face assessments are less cost-effective, and researchers often rely on surveys or activity trackers to assess outcomes. However, there is limited eviden...

This study aims to compare the effectiveness, engagement, usability, and acceptability of a web-based, computer-tailored physical activity intervention (provided as video or text) between participants who were matched or mismatched to their self-reported learning style (visual and auditory delivery through video or text-based information). Generali...

Background: Achieving system-level, sustainable ‘scale-up’ of interventions is the epitome of successful translation of evidence-based approaches in population health. In physical activity promotion, few evidence-based interventions reach implementation at scale or become embedded within systems for sustainable health impact. This is despite the va...

Background Few studies have investigated the impact of web-based physical activity interventions on mental health outcomes. Therefore, this study examined the impact of a web-based personally tailored physical activity intervention on depression, anxiety, stress and quality of life. Methods 501 participants were randomised into either a control gr...

Aims: Dietary modification is essential for the secondary prevention of cardiovascular disease. However, there are limited published evidence syntheses to guide practice in the cardiac rehabilitation (CR) setting. This systematic review's objective was to assess effectiveness and reporting of nutrition interventions to optimize dietary intake in a...

Background: Gamification is purported to enhance engagement with health behavior apps, ultimately improving their effectiveness. This study aimed to examine (1) whether the inclusion of gamification features in a physical activity smartphone app was associated with improved app usage and goal adherence, describe (2) use of the gamification features...

Objective To examine the joint associations between meeting guidelines for physical activity (PA) and sleep duration and all-cause mortality risk among adults.Methods Participants were adults (n = 282,473) aged 18–84 years who participated in the 2004–2014 US National Health Interview Survey. Mortality status was ascertained using the National Deat...

Type 2 diabetes mellitus (T2DM) accounts for approximately 90% of diabetes cases globally. Regular physical activity is regarded as one of the key components in T2DM management. Aerobic exercise was traditionally recommended; however, there is a growing body of research examining the independent effect of resistance training (RT) on glycemic contro...

Background: The COVID-19 global pandemic greatly impacted lifestyles and physical activity routines. This study explored how the COVID-19 pandemic impacted participant experience and motivation in ecofit, a large, community-based, multicomponent intervention that supports aerobic and resistance-based physical activity using publicly available, out...

Participating in physical activity is beneficial for health. Whilst Aboriginal children possess high levels of physical activity, this declines rapidly by early adolescence. Low physical activity participation is a behavioral risk factor for chronic disease, which is present at much higher rates in Australian Aboriginal communities compared to non-...

Background Outdoor gym installations have become a popular initiative by local government agencies globally to increase community-based physical activity. Despite their rapid spread, usage rates and user characteristics are not well described, particularly the mode/type of activity performed. This study aims to investigate the proportion and timing...

BACKGROUND Mobile health apps that promote physical activity are being developed at a rapid rate. App-based interventions have the potential for wide reach and therefore, may be a useful tool in up-scaling physical activity interventions. In larger scale interventions, face-to-face assessments are less cost effective, and researchers often rely on...

Purpose: This study examined the usage, acceptability, usability, perceived usefulness, and satisfaction of a web-based video-tailored physical activity (PA) intervention (“TaylorActive”) in adults. Methods: In 2013–2014, 501 Australian adults aged 18+ years were randomized into a video-tailored intervention, text-tailored intervention, or control...

Social media provides a convenient platform for health campaigns. However, practitioners designing such campaigns are faced with a number of decisions regarding advertising formats and appeals. This study set out to compare the effectiveness of two advertising formats (image vs. video) and two advertising appeals (benefits of being active vs. app a...

This study involved the design and evaluation of the High-Intensity Interval Training Self-Efficacy Questionnaire (HIIT-SQ). Phase 1: Questionnaire items were developed. Phase 2: Australian adolescents (N = 389, 16.0 ± 0.4 years, 41.10% female) completed the HIIT-SQ, and factorial validity of the measurement model was explored. Phase 3: Adolescents...

Importance Cardiorespiratory fitness is an important marker of childhood health and low fitness levels are a risk factor for disease later in life. Levels of children's fitness have declined in recent decades. Whether school-based physical activity interventions can increase fitness at the population level remains unclear. Objective To evaluate th...

Abstract Background To examine if a composite activity-sleep behaviour index (ASI) mediates the effects of a combined physical activity and sleep intervention on symptoms of depression, anxiety, or stress, quality of life (QOL), energy and fatigue in adults. Methods This analysis used data pooled from two studies: Synergy and Refresh. Synergy: Phys...

Background ecofit is an evidence-based multi-component physical activity intervention that integrates smartphone technology, the outdoor environment, and social support. In a previous efficacy trial, significant improvements were found across several clinical, fitness, and mental health outcomes among adults at risk of (or with) type 2 diabetes. M...

Participation in regular physical activity has significant physical, psychological, and social benefits, including the prevention and treatment of Type 2 Diabetes (T2D). The primary aim of this paper was to evaluate the impact of the CoFit physical activity intervention on depression and anxiety symptoms among adults at risk of, or diagnosed with,...

Purpose To evaluate the performance of Facebook advertisements for a physical activity smartphone app at different times of the year. Design A repeated cross-sectional study examined the cost and engagement levels of advertisements during 3 time points: Post-Easter April-May 2019 , Pre-Summer October 2019 , and New Year January 2020 . Setting Adv...

Understanding for whom behaviour change interventions work is important, however there is a lack of studies examining potential moderators in such interventions. This study investigated potential moderators on the effectiveness of a computer-tailored intervention to increase physical activity among Australian adults. People who had <150 minutes of...

Technology-based physical activity programs are a novel solution to the major public health issue of physical inactivity. However, to be successful, there must be a large and population-appropriate uptake, which depends heavily on promotion. This study evaluates the effectiveness of an advertising campaign to disseminate a physical activity smartph...

Background Regular engagement in physical activity has well-established physical and psychological health benefits. Despite this, over a quarter of the global adult population is insufficiently physically active. Physical activity interventions grounded in behaviour change theory, such as the social-cognitive theory, are widely considered to be mor...

Background Cardiorespiratory fitness (CRF) is an important marker of current and future health status. The primary aim of our study was to evaluate the impact of a time-efficient school-based intervention on older adolescents’ CRF. Methods Two-arm cluster randomised controlled trial conducted in two cohorts (February 2018 to February 2019 and Febr...

Process evaluations can help to optimise the implementation of school-based physical activity interventions. The purpose of this paper is to describe the process evaluation of a school-based high-intensity interval training (HIIT) program for older adolescent students, known as Burn 2 Learn (B2L). B2L was evaluated via a cluster randomised controll...

Objectives Some online, personally tailored, text-based physical activity interventions have proven effective. However, people tend to ‘skim’ and ‘scan’ web-based text rather than thoroughly read their contents. In contrast, online videos are more engaging and popular. We examined whether web-based personally tailored physical activity videos were...

Background: This study compared the efficacy of two multi-component m-health interventions with a wait-list control group on body weight (primary outcome), and secondary outcomes of cardiovascular risk factors, lifestyle behaviours, and mental health. Methods: Three-arm randomised controlled trial (Enhanced: physical activity, diet, sleep, Tradi...

Objectives: Examining mediators of intervention efficacy in an m-health intervention targeting physical activity and sleep in 160 Australian adults. Design: Nationwide randomised controlled trial. Main outcome measures: Moderate- and vigorous-intensity physical activity (MVPA), assessed using the Active Australia Questionnaire; sleep quality (Pitts...

Introduction: Appealing approaches to increasing physical activity levels are needed. This study evaluated whether a social and gamified smartphone app (Active Team) could be one such approach. Study design: A 3-group cluster RCT compared the efficacy of Active Team with a basic self-monitoring app and waitlist control group. Setting/participan...

Background: Poor sleep health is highly prevalent. Physical activity is known to improve sleep quality but not specifically targeted in sleep interventions. Purpose: To compare the efficacy of a combined physical activity and sleep intervention with a sleep-only intervention and a wait-list control, for improving sleep quality in middle-aged adu...

Background: This study examined the criterion validity of the online Active Australia Survey, using accelerometry as the criterion, and whether self-report bias was related to level of activity, age, sex, education, body mass index and health-related quality of life. Methods: The online Active Australia Survey was validated against the GENEActiv...

Background: Substantial evidence links activity domains with health and well-being; however, research has typically examined time-use behaviors independently, rather than considering daily activity as a 24-hour time-use composition. This study used compositional data analysis to estimate the difference in physical and mental well-being associated...

Introduction This study evaluated the psychometric properties of the PERMA Profiler, a 15-item self-report measurement tool designed to measure Seligman’s five pillars of wellbeing: Positive emotions, Relationships, Engagement, Meaning, and Accomplishment. Methods Australian adults (N = 439) completed the PERMA Profiler and measures of physical an...

This study examined the psychometric properties of a newly developed instrument to assess psychosocial determinants of sleep hygiene. Baseline data ( n = 160) from an m-health physical activity and sleep intervention were analyzed to examine scale validity. Additional participants ( n = 20) were recruited to compute test–retest reliability. Four of...

Background The success of a mobile phone app in changing health behavior is thought to be contingent on engagement, commonly operationalized as frequency of use. Objective This subgroup analysis of the 2 intervention arms from a 3-group randomized controlled trial aimed to examine user engagement with a 100-day physical activity intervention deliv...

Objectives: Supporting healthy ageing is a key priority worldwide. Physical activity, diet quality and sleep are all associated with health outcomes, but few studies have explored their independent associations with all-cause mortality in an older population in the same model. The study aim was to examine associations between step-count, self-repo...

Introduction Interventions that improve both physical activity and sleep quality may be more effective in improving overall health. The purpose of the Synergy Study is to test the efficacy of a mobile health combined behavior intervention targeting physical activity and sleep quality. Study design Randomized, waitlist-controlled trial. Setting/pa...

Purpose: Fatigue is a common and potentially disabling symptom in patients with cancer. It can often be effectively reduced by exercise. Yet, effects of exercise interventions might differ across subgroups. We conducted a meta-analysis using individual patient data of randomized controlled trials (RCTs) to investigate moderators of exercise interv...

Introduction: Regular physical activity can significantly reduce the risk of numerous chronic diseases, and improve bone density and mental health. Yet, only 50% of Australian adults meet the aerobic physical activity guidelines and 9-19% meet the resistance-based physical activity guidelines. The aim of this study is to enhance community-based ae...

Purpose To explore whether there was a difference in objectively measured physical activity and study participation between people who received their preferred study group allocation (matched) and those who did not receive their preferred study group (mismatched). Design Secondary data from the NewCOACH randomized controlled trial. Setting Insuff...

Objectives: While outdoor gyms are being rapidly installed around the globe, little is known about their implications on physical activity, and fitness and other health-related outcomes. The primary objective of this systematic review was to examine the effects of outdoor gyms on physical activity, fitness and other health-related outcomes. Second...

Background: Homophily is the tendency to associate with friends similar to ourselves. This study explored the effects of homophily on team formation in a physical activity challenge in which "captains" signed up their Facebook friends to form teams. Methods: This study assessed whether participants (n = 430) were more similar to their teammates...

Background The study aim was to examine the mechanisms of physical activity behaviour change in the multi-component eCoFit randomised controlled trial (RCT) among adults diagnosed with, or at risk of, T2D. Method The RCT included two phases: phase 1 (weeks 1–10) integrated group sessions (outdoor physical activity and cognitive mentoring) and the...

Background Although gender is an important determinant of health behaviour with males less likely to perform health-protective behaviours, samples in health behaviour research are heavily biased towards females. This study investigated the use of online social network, Facebook, to reach and recruit inactive males to a team-based, social, and gamif...

Healthy Dads Healthy Kids (HDHK) was the first program internationally to specifically target overweight and obese fathers to improve their children’s health. In previous randomized controlled trials, HDHK generated meaningful short-term improvements in the adiposity, physical activity, and eating behaviors of both fathers and children. The aim of...

BACKGROUND The success of a mobile phone app in changing health behavior is thought to be contingent on engagement, commonly operationalized as frequency of use. OBJECTIVE This subgroup analysis of the 2 intervention arms from a 3-group randomized controlled trial aimed to examine user engagement with a 100-day physical activity intervention deliv...

Introduction This trial aims to investigate the impact of a school-based physical activity programme, involving high-intensity interval training (HIIT), on the physical, mental and cognitive health of senior school students. Methods and analysis The Burn 2 Learn (B2L) intervention will be evaluated using a two-arm parallel group cluster randomised...

Introduction: Type 2 diabetes mellitus (T2DM) is a global public health concern. Aerobic physical activity (PA) and resistance training (RT) play significant roles in the prevention and management of T2DM. The aim of this pilot trial is to determine the preliminary efficacy and confirm feasibility of referral to exercise physiologists, psychologis...

This study involved the design and evaluation of the High-Intensity Interval Training Self-Efficacy Questionnaire (HIIT-SQ). Phase 1: Questionnaire items were developed. Phase 2: Australian adolescents ( N = 389, 16.0 ± 0.4 years, 41.10% female) completed the HIIT-SQ, and factorial validity of the measurement model was explored. Phase 3: Adolescent...

Background General practitioners (GPs) cite time as a barrier to physical activity counseling. An alternative for time-poor GPs in Australia is the referral of insufficiently active patients to exercise physiologists (EPs). As data on the predictors of adherence to physical activity counseling interventions are limited, this study aimed to identify...

Males are under-represented in physical activity research, often comprising just 20% of sample participants. Online social networks such as Facebook offer promise as a recruitment platform to engage harder-to-reach populations based on demographic segmentation but there is little evidence available on how to best leverage the potential of this appr...

Background: Exercise effects in cancer patients often appear modest, possibly because interventions rarely target patients most in need. This study investigated the moderator effects of baseline values on the exercise outcomes of fatigue, aerobic fitness, muscle strength, quality of life (QoL), and self-reported physical function (PF) in cancer pa...

Introduction: Traditional behavioural weight loss trials targeting improvements in physical activity and diet are modestly effective. It has been suggested that sleep may have a role in weight loss and maintenance. Improving sleep health in combination with physical activity and dietary behaviours may be one strategy to enhance traditional behavio...

Purpose: This study was designed to assess the feasibility and preliminary efficacy of a teacher-facilitated high-intensity interval training intervention for older adolescents (ie, 16-18 y). Methods: Two secondary schools from New South Wales, Australia were recruited, and participants (ie, grade 11 students; 16.2 [0.4] y) were randomized at th...

Purpose: Insufficient physical activity (PA) and inadequate sleep quality (SQ) and sleep duration (SD) are highly prevalent behaviours that increase the risk of developing many chronic health conditions. Evidence regarding bi-directional relationships between PA, SQ and SD is inconsistent. As changes in one of these behaviours may impact on the ot...

Objective: To evaluate the effectiveness of interventions targeting alcohol consumption, drug use and smoking for college/university students. Participants: College/University students Methods: Studies were eligible if: (1)included students attending universities/colleges; (2)implemented in a university/college setting; (3)aimed to improve at least...

Introduction ParticipACTION is a Canadian physical activity communications and social marketing organization relaunched in 2007. This study assesses the capacity of Canadian organizations to adopt, implement, and promote physical activity initiatives. The four objectives were to compare findings from baseline (2008) and follow-up (2013) with respec...

Introduction ParticipACTION est un organisme canadien relancé en 2007 dédié à la communication et au marketing social en matière d’activité physique. Cette étude porte sur le pouvoir d'action des organismes canadiens dans l'adoption, la mise en oeuvre et la promotion des initiatives en ce domaine. Nos objectifs étaient de comparer les résultats de...

Background - Fatigue is one of the most common and disabling comlaints in atients with breast cancer and can effectively be reduced by hysical exercise, with small to moderate effect sizes. To identify heterogeneity in resonses to exercise and to further ersonalize exercise rescritions, moderators of exercise effects on fatigue should be investigat...

Introduction There is a need to reduce physical inactivity and poor sleep health in the adult population to decrease chronic disease rates and the associated burden. Given the high prevalence of these risk behaviours, effective interventions with potential for wide reach are warranted. Methods and analysis The aim of this two-arm RCT will be to te...

Many adults without a diagnosed sleep disorder report poor sleep health, which is defined by dissatisfactory levels of sleep duration, sleep quality, or the timing of sleep. No previous review has summarized and described interventions targeting poor sleep health in this population. This meta-analysis aimed to quantify the efficacy of behavioral an...

Background: Physical inactivity and poor dietary habits in women pose a clear public health burden. Mothers are generally the main female role model for daughters, therefore, targeting intergenerational females simultaneously may be a novel approach. However, the effectiveness of this approach to improve physical activity, fitness, nutrition and a...

Objective: Interventions to promote physical activity for sedentary patients seen in general practice may be a way to reduce the burden of chronic disease. Coaching by an exercise physiologist is publicly funded in Australia, but cost effectiveness has not been documented. Methods: In a three-arm randomised controlled trial, face-to-face coachin...

Objective To explore young people’s perceptions of pedometers and investigate behaviours exhibited while being monitored. Design Qualitative design using six focus groups with participants (mean age 14.7 years). Setting Study participants ( n = 24) were randomly selected from a previous study of 123 young people aged 14–15 years from three second...

Background Physical inactivity is a leading preventable cause of chronic disease and premature death globally, yet over half of the adult Australian population is inactive. To address this, web-based physical activity interventions, which have the potential to reach large numbers of users at low costs, have received considerable attention. To fully...

Background: Participating in regular physical activity is a recommended cancer recovery strategy for breast cancer survivors. However, tailored support services are not widely available and most survivors are insufficiently active to obtain health benefits. Delivering tailored programs via the Internet offers one promising approach. However, recen...