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author:("dalle, Lance")
1.  Is a threshold-based model a superior method to the relative percent concept for establishing individual exercise intensity? a randomized controlled trial 
Exercise intensity is arguably the most critical component of the exercise prescription model. It has been suggested that a threshold based model for establishing exercise intensity might better identify the lowest effective training stimulus for all individuals with varying fitness levels; however, experimental evidence is lacking. The purpose of this study was to compare the effectiveness of two exercise training programs for improving cardiorespiratory fitness: threshold based model vs. relative percent concept (i.e., % heart rate reserve – HRR).
Apparently healthy, but sedentary men and women (n = 42) were randomized to a non-exercise control group or one of two exercise training groups. Exercise training was performed 30 min/day on 5 days/week for 12weeks according to one of two exercise intensity regimens: 1) a relative percent method was used in which intensity was prescribed according to percentages of heart rate reserve (HRR group), or 2) a threshold based method (ACE-3ZM) was used in which intensity was prescribed according to the first ventilatory threshold (VT1) and second ventilatory threshold (VT2).
Thirty-six men and women completed the study. After 12weeks, VO2max increased significantly (p < 0.05 vs. controls) in both HRR (1.76 ± 1.93 mL/kg/min) and ACE-3ZM (3.93 ± 0.96 mL/kg/min) groups. Repeated measures ANOVA identified a significant interaction between exercise intensity method and change in VO2max values (F = 9.06, p < 0.05) indicating that VO2max responded differently to the method of exercise intensity prescription. In the HRR group 41.7 % (5/12) of individuals experienced a favorable change in relative VO2max (Δ > 5.9 %) and were categorized as responders. Alternatively, exercise training in the ACE-3ZM group elicited a positive improvement in relative VO2max (Δ > 5.9 %) in 100 % (12/12) of the individuals.
A threshold based exercise intensity prescription: 1). elicited significantly (p < 0.05) greater improvements in VO2max, and 2). attenuated the individual variation in VO2max training responses when compared to relative percent exercise training. These novel findings are encouraging and provide important preliminary data for the design of individualized exercise prescriptions that will enhance training efficacy and limit training unresponsiveness.
Trial registration Identifier: ID NCT02351713 Registered 30 January 2015.
PMCID: PMC4491229  PMID: 26146564
Cardiorespiratory fitness; Cardiovascular Disease; Exercise prescription; Primary prevention; VO2max
2.  The prevalence of adverse cardiometabolic responses to exercise training with evidence-based practice is low 
The purpose of this study was to determine the prevalence of individuals who experienced exercise-induced adverse cardiometabolic response (ACR), following an evidence-based, individualized, community exercise program.
Prevalence of ACR was retrospectively analyzed in 332 adults (190 women, 142 men) before and after a 14-week supervised community exercise program. ACR included an exercise training-induced increase in systolic blood pressure of ≥10 mmHg, increase in plasma triglycerides (TG) of >37.0 mg/dL (≥0.42 mmol/L), or decrease in high-density lipoprotein cholesterol (HDL-C) of >4.0 mg/dL (0.12 mmol/L). A second category of ACR was also defined – this was ACR that resulted in a metabolic syndrome component (ACR-risk) as a consequence of the adverse response.
According to the above criteria, prevalence of ACR between baseline and post-program was systolic blood pressure (6.0%), TG (3.6%), and HDL-C (5.1%). The prevalence of ACR-risk was elevated TG (3.2%), impaired fasting blood glucose (2.7%), low HDL-C (2.2%), elevated waist circumference (1.3%), and elevated blood pressure (0.6%).
Evidence-based practice exercise programming may attenuate the prevalence of exercise training-induced ACR. Our findings provide important preliminary evidence needed for the vision of exercise prescription as a personalized form of preventative medicine to become a reality.
PMCID: PMC4319718  PMID: 25678806
evidence-based research; cardiovascular health; community-based research; metabolic health
3.  Is Moderate Intensity Exercise Training Combined with High Intensity Interval Training More Effective at Improving Cardiorespiratory Fitness than Moderate Intensity Exercise Training Alone? 
The purpose of this study was to compare the effectiveness of either continuous moderate intensity exercise training (CMIET) alone vs. CMIET combined with a single weekly bout of high intensity interval training (HIIT) on cardiorespiratory fitness. Twenty nine sedentary participants (36.3 ± 6.9 yrs) at moderate risk of cardiovascular disease were recruited for 12 weeks of exercise training on a treadmill and cycle ergometer. Participants were randomised into three groups: CMIET + HIIT (n = 7; 8-12 x 60 sec at 100% VO2max, 150 sec active recovery), CMIET (n = 6; 30 min at 45-60% oxygen consumption reserve (VO2R)) and a sedentary control group (n = 7). Participants in the CMIET + HIIT group performed a single weekly bout of HIIT and four weekly sessions of CMIET, whilst the CMIET group performed five weekly CMIET sessions. Probabilistic magnitude-based inferences were determined to assess the likelihood that the true value of the effect represents substantial change. Relative VO2max increased by 10.1% (benefit possible relative to control) in in the CMIET + HIIT group (32.7 ± 9.2 to 36.0 ± 11.5 mL·kg-1·min-1) and 3.9% (benefit possible relative to control) in the CMIET group (33.2 ± 4.0 to 34.5 ± 6.1 mL·kg-1·min-1), whilst there was a 5.7% decrease in the control group (30.0 ± 4.6 to 28.3 ± 6.5 mL·kg-1·min-1). It was ‘unclear’ if a clinically significant difference existed between the effect of CMIET + HIIT and CMIET on the change in VO2max. Both exercising groups showed clinically meaningful improvements in VO2max. Nevertheless, it remains ‘unclear’ whether one type of exercise training regimen elicits a superior improvement in cardiorespiratory fitness relative to its counterpart.
Key PointsBoth continuous moderate intensity exercise training (CMIET) alone and CMIET combined with a single weekly bout of high intensity interval training (CMIET + HIIT) elicit ‘possibly beneficial’ clinically meaningful improvements in cardiorespiratory fitness.Cardiorespiratory fitness improved by ~1.0 MET in the CMIET + HIIT exercise intervention group, which likely leads to important long-term prevention implications as a 1 MET increase in cardiorespiratory fitness has been linked with an 18% reduction in deaths due to CVD.There was 100% adherence to interval sessions in the CMIET + HIIT group, suggesting this combination of training can be well-tolerated in previously inactive overweight/obese individuals.
PMCID: PMC4126312  PMID: 25177202
Exercise prescription; prevention; risk factors; cardiovascular disease
4.  A community-based exercise intervention transitions metabolically abnormal obese adults to a metabolically healthy obese phenotype 
Lower habitual physical activity and poor cardiorespiratory fitness are common features of the metabolically abnormal obese (MAO) phenotype that contribute to increased cardiovascular disease risk. The aims of the present study were to determine 1) whether community-based exercise training transitions MAO adults to metabolically healthy, and 2) whether the odds of transition to metabolically healthy were larger for obese individuals who performed higher volumes of exercise and/or experienced greater increases in fitness.
Methods and results
Metabolic syndrome components were measured in 332 adults (190 women, 142 men) before and after a supervised 14-week community-based exercise program designed to reduce cardiometabolic risk factors. Obese (body mass index ≥30 kg · m2) adults with two to four metabolic syndrome components were classified as MAO, whereas those with no or one component were classified as metabolically healthy but obese (MHO). After community exercise, 27/68 (40%) MAO individuals (P<0.05) transitioned to metabolically healthy, increasing the total number of MHO persons by 73% (from 37 to 64). Compared with the lowest quartiles of relative energy expenditure and change in fitness, participants in the highest quartiles were 11.6 (95% confidence interval: 2.1–65.4; P<0.05) and 7.5 (95% confidence interval: 1.5–37.5; P<0.05) times more likely to transition from MAO to MHO, respectively.
Community-based exercise transitions MAO adults to metabolically healthy. MAO adults who engaged in higher volumes of exercise and experienced the greatest increase in fitness were significantly more likely to become metabolically healthy. Community exercise may be an effective model for primary prevention of cardiovascular disease.
PMCID: PMC4128798  PMID: 25120373
exercise; obesity; prevention; risk factors
5.  Measuring Physical Activity in a Cardiac Rehabilitation Population Using a Smartphone-Based Questionnaire 
Questionnaires are commonly used to assess physical activity in large population-based studies because of their low cost and convenience. Many self-report physical activity questionnaires have been shown to be valid and reliable measures, but they are subject to measurement errors and misreporting, often due to lengthy recall periods. Mobile phones offer a novel approach to measure self-reported physical activity on a daily basis and offer real-time data collection with the potential to enhance recall.
The aims of this study were to determine the convergent validity of a mobile phone physical activity (MobilePAL) questionnaire against accelerometry in people with cardiovascular disease (CVD), and to compare how the MobilePAL questionnaire performed compared with the commonly used self-recall International Physical Activity Questionnaire (IPAQ).
Thirty adults aged 49 to 85 years with CVD were recruited from a local exercise-based cardiac rehabilitation clinic in Auckland, New Zealand. All participants completed a demographics questionnaire and underwent a 6-minute walk test at the first visit. Subsequently, participants were temporarily provided a smartphone (with the MobilePAL questionnaire preloaded that asked 2 questions daily) and an accelerometer, which was to be worn for 7 days. After 1 week, a follow-up visit was completed during which the smartphone and accelerometer were returned, and participants completed the IPAQ.
Average daily physical activity level measured using the MobilePAL questionnaire showed moderate correlation (r=.45; P=.01) with daily activity counts per minute (Acc_CPM) and estimated metabolic equivalents (MET) (r=.45; P=.01) measured using the accelerometer. Both MobilePAL (beta=.42; P=.008) and age (beta=–.48, P=.002) were significantly associated with Acc_CPM (adjusted R2=.40). When IPAQ-derived energy expenditure, measured in MET-minutes per week (IPAQ_met), was considered in the predicted model, both IPAQ_met (beta=.51; P=.001) and age (beta=–.36; P=.016) made unique contributions (adjusted R2=.47, F 2,27=13.58; P<.001).There was also a significant association between the MobilePAL and IPAQ measures (r=.49, beta=.51; P=.007).
A mobile phone–delivered questionnaire is a relatively reliable and valid measure of physical activity in a CVD cohort. Reliability and validity measures in the present study are comparable to existing self-report measures. Given their ubiquitous use, mobile phones may be an effective method for physical activity surveillance data collection.
PMCID: PMC3636157  PMID: 23524251
cellular phone; self report; motor activity; bias; cardiovascular diseases
6.  A mHealth cardiac rehabilitation exercise intervention: findings from content development studies 
Involving stakeholders and consumers throughout the content and study design ensures interventions are engaging and relevant for end-users. The aim of this paper is to present the content development process for a mHealth (mobile phone and internet-based) cardiac rehabilitation (CR) exercise intervention.
An innovative mHealth intervention was developed with patient input using the following steps: conceptualization, formative research, pre-testing, and pilot testing. Conceptualization, including theoretical and technical aspects, was undertaken by experts. For the formative component, focus groups and interviews with cardiac patients were conducted to discuss their perceptions of a mHealth CR program. A general inductive thematic approach identified common themes. A preliminary library of text and video messages were then developed. Participants were recruited from CR education sessions to pre-test and provide feedback on the content using an online survey. Common responses were extracted and compiled. An iterative process was used to refine content prior to pilot testing and conduct of a randomized controlled trial.
38 CR patients and 3 CR nurses participated in the formative research and 20 CR patients participated in the content pre-testing. Participants perceived the mHealth program as an effective approach to inform and motivate patients to exercise. For the qualitative study, 100% (n = 41) of participants thought it to be a good idea, and 11% of participants felt it might not be useful for them, but would be for others. Of the 20 participants who completed the online survey, 17 out of 20 (85%) stated they would sign up to a program where they could receive information by video messages on a website, and 12 out of 20 (60%) showed interest in a texting program. Some older CR patients viewed technology as a potential barrier as they were unfamiliar with text messaging or did not have mobile phones. Steps to instruct participants to receive texts and view the website were written into the study protocol. Suggestions to improve videos and wording of texts were fed back to the content development team and refined.
Most participants thought a mHealth exercise program was an effective way to deliver exercise-based CR. The results were used to develop an innovative multimedia exercise intervention. A randomized controlled trial is currently underway.
Trial registration
PMCID: PMC3442998  PMID: 22646848
Cardiac rehabilitation; Exercise; Telemedicine; Internet
7.  Relationship Between %Heart Rate Reserve And %VO2 Reserve During Elliptical Crosstrainer Exercise 
The primary purpose of the study was to determine the relationships between %HRR vs. %VO2R and %HRR vs. %VO2max during maximal elliptical crosstrainer (ECT) exercise. A secondary aim was to compare the %HRR vs. %VO2R and %HRR vs. %VO2max relationships between maximal ECT and treadmill (TM) exercise. Adult subjects (n = 48) completed a maximal exercise test on the ECT, with a subgroup (N = 24) also performing a maximal exercise test on the TM. Continuous HR and VO2 data were analyzed via linear regression to determine y-intercept and slope values for %HRR vs. %VO2R and %HRR vs. %VO2max. Student t-tests were used to determine whether the mean y-intercept and slope values differed from the line of identity (y-intercept = 0, slope = 1). For each group, both the y-intercept and slope for %HRR vs. %VO2R fit the line of identity. Conversely, for all groups both the y-intercept and slope for %HRR vs. %VO2max were significantly different (p < 0.001) from the line of identity (y-intercept ≠ 0, slope ≠ 1). In comparing the regressions of %HRR vs. %VO2R between exercise modes, there were no significant differences (p > 0.05) for either y-intercept (ECT = 0.3 vs. TM = -0.3, p = 0.435) or slope (ECT = 1.01 vs. TM = 1.00, p = 0.079) values. In agreement with previous research on TM and cycle exercise, it was found that %HRR is more closely aligned with %VO2R, rather than %VO2max during ECT exercise. Additionally, it was found that the regressions of %HRR vs. %VO2R and %HRR vs. %VO2max were equivalent between the ECT and TM.
Key PointsThe present study showed that %HRR is aligned with %VO2R, not %VO2max, during maximal ellipitcal crosstrainer exercise.It was found that the relationships between %HRR vs. %VO2R and %HRR vs. %VO2max were equivalent between the ellipitcal crosstrainer and treadmill.This study revealed that the elliptical crosstrainer produced similar maximal physiological values (VO2max, HRmax, RERmax) compared to treadmill running during VO2max testing.
PMCID: PMC3861769  PMID: 24357963
Exercise mode; regression; exercise prescription

Results 1-7 (7)