Browsing by Author "Aguiar, Elroy J."

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    Cadence (steps/min) and relative intensity in 21 to 60-year-olds: the CADENCE-adults study
    (BMC, 2021) McAvoy, Cayla R.; Moore, Christopher C.; Aguiar, Elroy J.; Ducharme, Scott W.; Schuna, John M., Jr.; Barreira, Tiago V.; Chase, Colleen J.; Gould, Zachary R.; Amalbert-Birriel, Marcos A.; Chipkin, Stuart R.; Staudenmayer, John; Tudor-Locke, Catrine; Mora-Gonzalez, Jose; University of North Carolina; University of North Carolina Charlotte; University of North Carolina Chapel Hill; University of Alabama Tuscaloosa; California State University Long Beach; Oregon State University; Syracuse University; University of Massachusetts Amherst
    Background: Heuristic cadence (steps/min) thresholds of >= 100 and >= 130 steps/min correspond with absolutely-defined moderate (3 metabolic equivalents [METs]; 1 MET = 3.5 mL O-2 center dot kg(- 1)center dot min(- 1)) and vigorous (6 METs) intensity, respectively. Scarce evidence informs cadence thresholds for relatively-defined moderate (>= 64% heart rate maximum [HRmax = 220-age], >= 40%HR reserve [HRR = HRmax -HRresting, and >= 12 Rating of Perceived Exertion [RPE]); or vigorous intensity (>= 77%HRmax, >= 60%HRR, and >= 14 RPE). Purpose: To identify heuristic cadence thresholds corresponding with relatively-defined moderate and vigorous intensity in 21-60-year-olds. Methods: In this cross-sectional study, 157 adults (40.4 +/- 11.5 years; 50.6% men) completed up to twelve 5-min treadmill bouts, beginning at 0.5 mph and increasing by 0.5 mph. Steps were directly observed, HR was measured with chest-worn monitors, and RPE was queried in the final minute of each bout. Segmented mixed model regression and Receiver Operating Characteristic (ROC) curve analyses identified optimal cadence thresholds, stratified by age (21-30, 31-40, 41-50, and 51-60 years). Reconciliation of the two analytical models, including trade-offs between sensitivity, specificity, positive and negative predictive values, and overall accuracy, yielded final heuristic cadences. Results: Across all moderate intensity indicators, the segmented regression models estimated optimal cadence thresholds ranging from 123.8-127.5 (ages 21-30), 121.3-126.0 (ages 31-40), 117.7-122.7 (ages 41-50), and 113.3-116.1 steps/min (ages 51-60). Corresponding values for vigorous intensity were 140.3-144.1, 140.2-142.6, 139.3-143.6, and 131.6-132.8 steps/min, respectively. ROC analysis estimated chronologically-arranged age groups' cadence thresholds ranging from 114.5-118, 113.5-114.5, 104.6-112.9, and 103.6-106.0 across all moderate intensity indicators, and 127.5, 121.5, 117.2-123.2, and 113.0 steps/min, respectively, for vigorous intensity. Conclusions: Heuristic cadence thresholds corresponding to relatively-defined moderate intensity for the chronologically-arranged age groups were >= 120, 120, 115, and 105 steps/min, regardless of the intensity indicator (i.e., % HRmax, %HRR, or RPE). Corresponding heuristic values for vigorous intensity indicators were >= 135, 130, 125, and 120 steps/min. These cadences are useful for predicting/programming intensity aligned with age-associated differences in physiological response to, and perceived experiences of, moderate and/or vigorous intensity.
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    Cadence (steps/min) and relative intensity in 21 to 60-year-olds: the CADENCE-adults study (vol 18, 27, 2021)
    (BMC, 2022) McAvoy, Cayla R.; Moore, Christopher C.; Aguiar, Elroy J.; Ducharme, Scott W.; Schuna, John M., Jr.; Barreira, Tiago V.; Chase, Colleen J.; Gould, Zachary R.; Amalbert-Birriel, Marcos A.; Chipkin, Stuart R.; Staudenmayer, John; Tudor-Locke, Catrine; Mora-Gonzalez, Jose; University of North Carolina; University of North Carolina Charlotte; University of North Carolina Chapel Hill; University of Alabama Tuscaloosa; California State University Long Beach; Oregon State University; Syracuse University; University of Massachusetts Amherst
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    Cadence-based Classification of Minimally Moderate Intensity During Overground Walking in 21-to 40-Year-Old Adults
    (Human Kinetics, 2019) Aguiar, Elroy J.; Gould, Zachary R.; Ducharme, Scott W.; Moore, Chris C.; McCullough, Aston K.; Tudor-Locke, Catrine; University of Alabama Tuscaloosa; University of Massachusetts Amherst; California State University Long Beach; University of North Carolina; University of North Carolina Charlotte
    Background: A walking cadence of >= 100 steps/min corresponds to minimally moderate intensity, absolutely defined as >= 3 metabolic equivalents (METs). This threshold has primarily been calibrated during treadmill walking. There is a need to determine the classification accuracy of this cadence threshold to predict intensity during overground walking. Methods: In this laboratory-based cross-sectional investigation, participants (N = 75, 49.3% women, age 21-40 y) performed a single 5-minute overground (hallway) walking trial at a self-selected preferred pace. Steps accumulated during each trial were hand tallied and converted to cadence (steps/min). Oxygen uptake was measured using indirect calorimetry and converted to METs. The classification accuracy (sensitivity, specificity, overall accuracy, and positive predictive value) of >= 100 steps/min to predict >= 3METs was calculated. Results: A cadence threshold of =100 steps/min yielded an overall accuracy (combined sensitivity and specificity) of 73.3% for predicting minimally moderate intensity. Moreover, for individuals walking at a cadence >= 100 steps/min, the probability (positive predictive value) of achieving minimally moderate intensity was 80.3%. Conclusions: Although primarily developed using treadmill-based protocols, a cadence threshold of >= 100 steps/min for young adults appears to be a valid heuristic value (evidence-based, rounded, practical) associated with minimally moderate intensity during overground walking performed at a self-selected preferred pace.
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    A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-adults study
    (BMC, 2022) Mora-Gonzalez, Jose; Gould, Zachary R.; Moore, Christopher C.; Aguiar, Elroy J.; Ducharme, Scott W.; Schuna, John M., Jr.; Barreira, Tiago, V; Staudenmayer, John; McAvoy, Cayla R.; Boikova, Mariya; Miller, Taavy A.; Tudor-Locke, Catrine; University of Granada; University of North Carolina; University of North Carolina Charlotte; University of Massachusetts Amherst; University of North Carolina Chapel Hill; University of Alabama Tuscaloosa; California State University Long Beach; Oregon State University; Syracuse University
    Background Standardized validation indices (i.e., accuracy, bias, and precision) provide a comprehensive comparison of step counting wearable technologies. Purpose To expand a previously published child/youth catalog of validity indices to include adults (21-40, 41-60 and 61-85 years of age) assessed across a range of treadmill speeds (slow [0.8-3.2 km/h], normal [4.0-6.4 km/h], fast [7.2-8.0 km/h]) and device wear locations (ankle, thigh, waist, and wrist). Methods Two hundred fifty-eight adults (52.5 +/- 18.7 years, 49.6% female) participated in this laboratory-based study and performed a series of 5-min treadmill bouts while wearing multiple devices; 21 devices in total were evaluated over the course of this multi-year cross-sectional study (2015-2019). The criterion measure was directly observed steps. Computed validity indices included accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV). Results Over the range of normal speeds, 15 devices (Actical, waist-worn ActiGraph GT9X, activPAL, Apple Watch Series 1, Fitbit Ionic, Fitbit One, Fitbit Zip, Garmin vivoactive 3, Garmin vivofit 3, waist-worn GENEActiv, NL-1000, PiezoRx, Samsung Gear Fit2, Samsung Gear Fit2 Pro, and StepWatch) performed at < 5% MAPE. The wrist-worn ActiGraph GT9X displayed the worst accuracy across normal speeds (MAPE = 52%). On average, accuracy was compromised across slow walking speeds for all wearable technologies (MAPE = 40%) while all performed best across normal speeds (MAPE = 7%). When analyzing the data by wear locations, the ankle and thigh demonstrated the best accuracy (both MAPE = 1%), followed by the waist (3%) and the wrist (15%) across normal speeds. There were significant effects of speed, wear location, and age group on accuracy and bias (both p < 0.001) and precision (p <= 0.045). Conclusions Standardized validation indices cataloged by speed, wear location, and age group across the adult lifespan facilitate selecting, evaluating, or comparing performance of step counting wearable technologies. Speed, wear location, and age displayed a significant effect on accuracy, bias, and precision. Overall, reduced performance was associated with very slow walking speeds (0.8 to 3.2 km/h). Ankle- and thigh-located devices logged the highest accuracy, while those located at the wrist reported the worst accuracy.
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    A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-Kids study
    (BMC, 2021) Gould, Zachary R.; Mora-Gonzalez, Jose; Aguiar, Elroy J.; Schuna, John M., Jr.; Barreira, Tiago, V; Moore, Christopher C.; Staudenmayer, John; Tudor-Locke, Catrine; University of Massachusetts Amherst; University of North Carolina; University of North Carolina Charlotte; University of Alabama Tuscaloosa; Oregon State University; Syracuse University; University of North Carolina Chapel Hill
    Background: Wearable technologies play an important role in measuring physical activity (PA) and promoting health. Standardized validation indices (i.e., accuracy, bias, and precision) compare performance of step counting wearable technologies in young people. Purpose: To produce a catalog of validity indices for step counting wearable technologies assessed during different treadmill speeds (slow [0.8-3.2 km/h], normal [4.0-6.4 km/h], fast [7.2-8.0 km/h]), wear locations (waist, wrist/arm, thigh, and ankle), and age groups (children, 6-12 years; adolescents, 13-17 years; young adults, 18-20 years). Methods: One hundred seventeen individuals (13.1 +/- 4.2 years, 50.4% female) participated in this cross-sectional study and completed 5-min treadmill bouts (0.8 km/h to 8.0 km/h) while wearing eight devices (Waist Actical, ActiGraph GT3X+, NL-1000, SW-200; Wrist ActiGraph GT3X+; Arm: SenseWear; Thigh: activPAL; Ankle: StepWatch). Directly observed steps served as the criterion measure. Accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV) were computed. Results: Five of the eight tested wearable technologies (i.e., Actical, waist-worn ActiGraph GT3X+, activPAL, StepWatch, and SW-200) performed at < 5% MAPE over the range of normal speeds. More generally, waist (MAPE = 4%), thigh (4%) and ankle (5%) locations displayed higher accuracy than the wrist location (23%) at normal speeds. On average, all wearable technologies displayed the lowest accuracy across slow speeds (MAPE = 50.1 +/- 35.5%), and the highest accuracy across normal speeds (MAPE = 15.9 +/- 21.7%). Speed and wear location had a significant effect on accuracy and bias (P < 0.001), but not on precision (P> 0.05). Age did not have any effect (P > 0.05). Conclusions: Standardized validation indices focused on accuracy, bias, and precision were cataloged by speed, wear location, and age group to serve as important reference points when selecting and/or evaluating device performance in young people moving forward. Reduced performance can be expected at very slow walking speeds (0.8 to 3.2 km/h) for all devices. Ankle-worn and thigh-worn devices demonstrated the highest accuracy. Speed and wear location had a significant effect on accuracy and bias, but not precision.
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    Classification of moderate-intensity overground walking speed in 21-to 85-year-old adults
    (Taylor & Francis, 2022) Zheng, Peixuan; Ducharme, Scott W.; Moore, Christopher C.; Tudor-Locke, Catrine; Aguiar, Elroy J.; University of Alabama Tuscaloosa; California State University Long Beach; University of North Carolina; University of North Carolina Chapel Hill; University of North Carolina Charlotte
    The Compendium of Physical Activities reports that walking at 2.5 mph associates with absolutely-defined moderate intensity (i.e., >= 3 metabolic equivalents [METs]). However, it is unclear whether this speed threshold is accurate during overground walking and/or across the adult age-span. This study aimed to identify optimal and heuristic speed thresholds associated with 3 METs during overground walking across age groups. Healthy adults (n = 248, 21-85 years old, 49% women) performed a 5-minute self-paced overground walking trial. Speed was measured using an electronic gait mat, and oxygen uptake was measured using indirect calorimetry and converted to METs. Optimal and heuristic thresholds and classification accuracy metrics were determined and compared using ROC curve analyses. Speed thresholds (95% CIs) associated with 3 METs for the whole sample, young (21-40 years), middle-aged (41-60 years) and older-aged (61-85 years) groups were 1.29 (1.25, 1.33), 1.30 (1,26, 1,35), and 1.25 (1.21, 1.29) m/s, respectively. Overall, 3 mph and 5 km/h performed better than 2.5 mph and 4.5 km/h in balancing both sensitivity and specificity (higher Youden's Indices). Overground walking speeds associated with 3 METs were similar across age groups. A heuristic threshold of 3 mph or 5 km/h may better identify absolutely-defined moderate intensity overground walking.
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    Development of a Cadence-based Metabolic Equation for Walking
    (Lippincott Williams & Wilkins, 2021) Moore, Christopher C.; Aguiar, Elroy J.; Ducharme, Scott W.; Tudor-Locke, Catrine; University of North Carolina; University of North Carolina Chapel Hill; University of Alabama Tuscaloosa; California State University Long Beach; University of North Carolina Charlotte
    Purpose: This study aimed to develop cadence-based metabolic equations (CME) for predicting the intensity of level walking and evaluate these CME against the widely adopted American College of Sports Medicine (ACSM) Metabolic Equation, which predicts walking intensity from speed and grade. Methods: Two hundred and thirty-five adults (21-84 yr of age) completed 5-min level treadmill walking bouts between 0.22 and 2.24 m.s(-1), increasing by 0.22 m.s(-1) for each bout. Cadence (in steps per minute) was derived by dividing directly observed steps by bout duration. Intensity (oxygen uptake; in milliliters per kilogram per minute) was measured using indirect calorimetry. A simple CME was developed by fitting a least-squares regression to the cadence-intensity relationship, and a full CME was developed through best subsets regression with candidate predictors of age, sex, height, leg length, body mass, body mass index (BMI), and percent body fat. Predictive accuracy of each CME and the ACSM metabolic equation was evaluated at normal (0.89-1.56 m.s(-1)) and all (0.22-2.24 m.s(-1)) walking speeds through k-fold cross-validation and converted to METs (1 MET = 3.5 mL.kg(-1).min(-1)). Results:On average, the simple CME predicted intensity within similar to 1.8 mL.kg(-1).min(-1) (similar to 0.5 METs) at normal walking speeds and with negligible (<0.01 METs) bias. Including age, leg length, and BMI in the full CME marginally improved predictive accuracy (<= 0.36 mL.kg(-1).min(-1) [<= 0.1 METs]), but may account for larger (up to 2.5 mL.kg(-1).min(-1) [0.72 MET]) deviations in the cadence-intensity relationships of outliers in age, stature, and/or BMI. Both CME demonstrated 23%-35% greater accuracy and 2.2-2.8 mL.kg(-1).min(-1) (0.6-0.8 METs) lower bias than the ACSM metabolic equation's speed-based predictions. Conclusions: Although the ACSM metabolic equation incorporates a grade component and is convenient for treadmill-based applications, the CME developed herein enables accurate quantification of walking intensity using a metric that is accessible during overground walking, as is common in free-living contexts.
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    The Dose-Response Effect of Short-Term Exercise on Cognitive Function
    (University of Alabama Libraries, 2022) Zheng, Peixuan; Aguiar, Elroy J.; University of Alabama Tuscaloosa
    Physical activity (PA) is increasingly recognized as an effective approach for improving cognitive function. However, it is unclear how short-term PA or physical inactivity might influence cognition, and whether this effect is associated with other health outcomes such as vascular function. A series of three studies were conducted to address this knowledge gap. The first study systematically reviewed and meta-analyzed 90 effects from 16 randomized controlled trials to examine the effect of acute exercise on cognitive function in healthy older adults aged 60 years or above. The results revealed that acute exercise elicited a small but significant improvement in cognitive function compared to the non-exercise control condition (standardized mean difference [SMD] = 0.17, p = 0.003), and greater improvements were found in time- than accuracy-related cognitive outcomes (SMD = 0.24 versus 0.11, p < 0.05). The second study investigated the effects of a single bout of moderate-intensity walking on cognitive and vascular function in physically inactive older adults aged 60 years or above. Compared to the control (sitting) condition, acute exercise (30-min walking at 100 steps/min) significantly improved performance in executive function, whereas reduced carotid to femoral pulse wave velocity (p-values < 0.05). Changes in processing speed and aortic augmentation index were similar between conditions (p > 0.05), whereas central mean arterial blood pressure was increased after sitting (p < 0.05) but remained unaltered after acute exercise (p > 0.05). The third study focused on the impact of short-term physical inactivity (i.e., walking below 5000 steps/day for one week) on cognitive performance and vascular function among physically active individuals aged 50 years or above. Results from the Bayesian analysis demonstrated minimal changes in all variables before versus after step reduction, indicating that one week of reduction in PA did not yield detrimental effects on cognitive performance and vascular function. Collectively, this body of work supports a small but positive effect of acute exercise on cognition among generally healthy older adults without cognitive impairment. In addition, significant associations were found between changes in cognitive performance with arterial stiffness and central blood pressure in response to acute exercise or short-term PA reduction.
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    Evaluation of a Type 2 diabetes risk reduction online program for women with recent gestational diabetes: a randomised trial
    (BMC, 2022) Taylor, Rachael; Rollo, Megan E.; Baldwin, Jennifer N.; Hutchesson, Melinda; Aguiar, Elroy J.; Wynne, Katie; Young, Ashley; Callister, Robin; Collins, Clare E.; University of Newcastle; Hunter Medical Research Institute; University of Alabama Tuscaloosa
    Background: To evaluate the preliminary efficacy, feasibility and acceptability of the 3-month Body Balance Beyond (BBB) online program among Australian women with overweight/obesity and recent gestational diabetes mellitus. Methods: Women were randomised into either: 1) High Personalisation (HP) (access to'BBB'website, video coaching sessions, text message support); 2) Medium Personalisation (MP) (website and text message support); or 3) Low Personalisation (LP) (website only). Generalised linear mixed models were used to evaluate preliminary efficacy, weight, diet quality, physical activity levels, self-efficacy and quality of life (QoL) at baseline and 3-months. Feasibility was assessed by recruitment and retention metrics and acceptability determined via online process evaluation survey at 3-months. Results: Eighty three women were randomised, with 76 completing the study. Self-efficacy scores showed significant improvements in confidence to resist eating in a variety of situations from baseline to 3-months in HP compared to MP and LP groups (P=.03). The difference in mean QoL scores favoured the HP compared to MP and LP groups (P=.03). Half of the women (HP n=17[81%], MP n=12[75%], LP n=9[56%]) lost weight at 3-months. No significant group-by-time effect were reported for other outcomes. Two-thirds of women in the HP group were satisfied with the program overall and 86% would recommend it to others, compared with 25% and 44% in the MP group, and 14% and 36% in the LP group, respectively. Conclusions: Video coaching sessions were associated with improvements in QoL scores and self-efficacy, however further refinement of the BBB website and text messages support could improve program acceptability.
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    The Feasibility and Preliminary Efficacy of an eHealth Lifestyle Program in Women with Recent Gestational Diabetes Mellitus: A Pilot Study
    (MDPI, 2020) Rollo, Megan E.; Baldwin, Jennifer N.; Hutchesson, Melinda; Aguiar, Elroy J.; Wynne, Katie; Young, Ashley; Callister, Robin; Haslam, Rebecca; Collins, Clare E.; University of Newcastle; University of Alabama Tuscaloosa
    Self-administered eHealth interventions provide a potential low-cost solution for reducing diabetes risk. The aim of this pilot randomised controlled trial (RCT) was to evaluate the feasibility, including recruitment, retention, preliminary efficacy (primary outcome) and acceptability (secondary outcome) of the "Body Balance Beyond" eHealth intervention in women with previous gestational diabetes mellitus (GDM). Women with overweight/obesity who had recent GDM (previous 24 months) were randomised into one of three groups: 1) high personalisation (access to "Body Balance Beyond" website, individual telehealth coaching via video call by a dietitian and exercise physiologist, and text message support); 2) low personalisation (website only); or 3) waitlist control. To evaluate preliminary efficacy, weight (kg), glycosylated hemoglobin, type A1C (HbA1c), cholesterol (total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL)), diet quality and moderate-vigorous physical activity were analysed at baseline and at 3 and 6 months using generalised linear mixed models. To investigate acceptability, process evaluation was conducted at 3 and 6 months. Of the 327 potential participants screened, 42 women (mean age 33.5 +/- 4.0 years and BMI 32.4 +/- 4.3 kg/m(2)) were randomised, with 30 (71%) completing the study. Retention at 6 months was 80%, 54% and 79% for high personalisation, low personalisation and waitlist control, respectively (reasons: personal/work commitments, n = 4; started weight-loss diet, n = 1; pregnant, n = 1; resources not useful, n = 1; and not contactable, n = 5). No significant group-by-time interactions were observed for preliminary efficacy outcomes, with the exception of HDL cholesterol, where a difference favoured the low personalisation group relative to the control (p = 0.028). The majority (91%) of women accessed the website in the first 3 months and 57% from 4-6 months. The website provided useful information for 95% and 92% of women at 3 and 6 months, respectively, although only a third of women found it motivating (30% and 25% at 3 and 6 months, respectively). Most women agreed that the telehealth coaching increased their confidence for improving diet (85%) and physical activity (92%) behaviours, although fewer women regarded the text messages as positive (22% and 31% for improving diet and physical activity, respectively). The majority of women (82% at 3 months and 87% at 6 months) in the high personalisation group would recommend the program to other women with GDM. Recruiting and retaining women with a recent diagnosis of GDM is challenging. The "Body Balance Beyond" website combined with telehealth coaching via video call is largely acceptable and useful for women with recent GDM. Further analysis of the effect on diabetes risk reduction in a larger study is needed.
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    Hemodynamic Responses to Resistance Exercise with Blood Flow Restriction Using a Practical Method Versus a Traditional Cuff-Inflation System
    (MDPI, 2022) Winchester, Lee J.; Blake, Morgan T.; Fleming, Abby R.; Aguiar, Elroy J.; Fedewa, Michael, V; Esco, Michael R.; Earley, Ryan L.; University of Alabama Tuscaloosa
    The aim of this study was to examine the potential differences in acute hemodynamic responses and muscular performance outcomes following resistance exercise between traditional blood flow restriction (TRA(BFR)) and a novel band tissue flossing method (BTFBFR). METHODS: Fifteen healthy young adults (23.27 +/- 2.69 years) visited the lab for three sessions (>= 72 h apart). Each session's exercise consisted of three sets of 20 maximum-effort seated leg extensions and flexions with one of three conditions: control (CON), TRA(BFR) (50% limb occlusion pressure (LOP)), or BTFBFR. During TRA(BFR) and BTFBFR sessions, occlusion was applied immediately prior to exercise and removed immediately after. Heart rate was collected prior to exercise, after onset of occlusion, immediately after exercise, and one-minute after removal of occlusion. Ultrasonography was performed prior to, and at least 30 s after, occlusion. RESULTS: BTFBFR caused greater reductions in arterial distance (14.28%, p = 0.010) and arterial area (28.43%, p = 0.020) than TRA(BFR). BTFBFR was able to significantly reduce arterial flow below pre-occlusion values, while TRA(BFR) did not. Both conditions caused significant elevations in heart rate following occlusion (TRA(BFR): +4.67 bpm, p = 0.046 and BTFBFR: +6.07 bpm, p = 0.034), immediately post-exercise (TRA(BFR): +56.93 bpm, p < 0.001 and BTFBFR: +52.79 bpm, p < 0.001) and one-minute post-exercise (TRA(BFR): +15.71, p = 0.003 and BTFBFR: +14.57, p < 0.001). Only BTFBFR caused significant reductions in performance as measured by average power per repetition. CONCLUSIONS: BTFBFR causes a more exaggerated decrease in arterial blood flow as well as muscular power when compared to traditional TRA(BFR) at 50% of LOP.
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    Mobility-related outcomes for periacetabular osteotomy in persons with acetabular dysplasia: setting the stage for measurement of real-world outcomes
    (Oxford University Press, 2022) Alrashdi, Naif Z.; Motl, Robert W.; Aguiar, Elroy J.; Ryan, Michael K.; Perumean-Chaney, Suzanne E.; Ithurburn, Matthew P.; University of Alabama Birmingham; Majmaah University; University of Illinois Chicago; University of Illinois Chicago Hospital; University of Alabama Tuscaloosa
    Periacetabular osteotomy (PAO) is a surgery for persons with symptomatic acetabular dysplasia (AD) that increases acetabular coverage of the femoral head for reducing hip pain and improving function. Patient-reported outcomes (PROs) are significantly improved following PAO, yet little is known regarding mobility-related outcomes. This narrative review provides a synthesis of evidence regarding PROs and mobility-related outcomes in persons with AD following PAO. We further identified important future research directions, chiefly the need for measurement of real-world outcomes. We searched PubMed using comprehensive predefined search terms. We included studies that (i) enrolled persons with AD undergoing PAO, (ii) included PROs and/or mobility-related outcomes and (iii) were written in English. We synthesized and summarized study characteristics and findings. Twenty-three studies were included in this review. Commonly evaluated PROs included pain (n = 14), hip function (n = 19) and quality of life (n = 9). Mobility-related outcomes included self-reported physical activity (PA; n = 11), walking speed and cadence (n = 4), device-measured PA (n = 2), and sit-to-stand, four-square-step and timed stair ascent tests (n = 1). Persons with AD had significant improvements in PROs following PAO, yet mobility-related outcomes (e.g. walking speed and device-measured PA levels) did not change over 1 year following PAO. Few studies have evaluated mobility-related outcomes following PAO, and these studies were of a low methodological quality. Future research might include experience sampling data collection approaches and body-worn devices as free-living, technology-driven methodologies to evaluate mobility and other outcomes in persons with AD undergoing PAO.
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    Proposed Mechanisms of Blood Flow Restriction Exercise for the Improvement of Type 1 Diabetes Pathologies
    (2021) Jones, Morgan T.; Aguiar, Elroy J.; Winchester, Lee J.; University of Alabama Tuscaloosa
    Individuals with type 1 diabetes suffer from impaired angiogenesis, decreased capillarization, and higher fatigability that influence their muscular system beyond the detriments caused by decreased glycemic control. In order to combat exacerbations of these effects, the American Diabetes Association recommends that individuals with type 1 diabetes participate in regular resistance exercise. However, traditional resistance exercise only induces hypertrophy when loads of 65% of an individual’s one repetition maximum are used. Combining blood flow restriction with resistance exercise may serve as a more efficient means for stimulating anabolic pathways that result in increased protein synthesis and angiogenesis at lower loads, while also promoting better glycemic control. The purpose of this paper is to provide a review on the literature surrounding the benefits of resistance exercise, specifically for individuals with type 1 diabetes, and postulate potential effects of combining resistance exercise with blood flow restriction in this clinical population.
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    Toward Harmonized Treadmill-Based Validation of Step-Counting Wearable Technologies: A Scoping Review
    (Human Kinetics, 2020) Moore, Christopher C.; McCullough, Aston K.; Aguiar, Elroy J.; Ducharme, Scott W.; Tudor-Locke, Catrine; University of North Carolina; University of North Carolina Chapel Hill; University of Massachusetts Amherst; University of Alabama Tuscaloosa; California State University Long Beach; University of North Carolina Charlotte
    The authors conducted a scoping review as a first step toward establishing harmonized (ie, consistent and compatible), empirically based best practices for validating step-counting wearable technologies. Purpose: To catalog studies validating step-counting wearable technologies during treadmill ambulation. Methods: The authors searched PubMed and SPORTDiscus in August 2019 to identify treadmill-based validation studies that employed the criterion of directly observed (including video recorded) steps and cataloged study sample characteristics, protocol details, and analytical procedures. Where reported, speed- and wear location-specific mean absolute percentage error (MAPE) values were tabulated. Weighted median MAPE values were calculated by wear location and a 0.2-m/s speed increment. Results: Seventy-seven eligible studies were identified: most had samples averaging 54% (SD = 5%) female and 27 (5) years of age, treadmill protocols consisting of 3 to 5 bouts at speeds of 0.8 (0.1) to 1.6 (0.2) m/s, and reported measures of bias. Eleven studies provided MAPE values at treadmill speeds of 1.1 to 1.8m/s; their weighted medianMAPE values were 7% to 11% for wrist-worn, 1% to 4% for waist-worn, and <= 1% for thigh-worn devices. Conclusions: Despite divergent study methodologies, the authors identified common practices and summarized MAPE values representing device step-count accuracy during treadmill walking. These initial empirical findings should be further refined to ultimately establish harmonized best practices for validating wearable technologies.
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    Using Cadence to Predict the Walk-to-Run Transition in Children and Adolescents: A Logistic Regression Approach
    (Taylor & Francis, 2021) Ducharme, Scott W.; Turner, Dusty S.; Pleuss, James D.; Moore, Christopher C.; Schuna, John M.; Tudor-Locke, Catrine; Aguiar, Elroy J.; California State University Long Beach; United States Military Academy; United States Department of Defense; United States Army; University of North Carolina; University of North Carolina Chapel Hill; Oregon State University; University of North Carolina Charlotte; University of Alabama Tuscaloosa
    The natural transition from walking to running occurs in adults at approximately equal to 140 steps/min. It is unknown when this transition occurs in children and adolescents. The purpose of this study was to develop a model to predict age- and anthropometry-specific preferred transition cadences in individuals 6-20 years of age. Sixty-nine individuals performed sequentially faster 5-min treadmill walking bouts, starting at 0.22 m/s and increasing by 0.22 m/s until completion of the bout during which they freely chose to run. Steps accumulated during each bout were directly observed and converted to cadence (steps/min). A logistic regression model was developed to predict preferred transition cadences using the best subset of parameters. The resulting model, which included age, sex, height, and BMI z-score, produced preferred transition cadences that accurately classified gait behaviour (k-fold cross-validated prediction accuracy =97.02%). This transition cadence ranged from 136-161 steps/min across the developmental age range studied. The preferred transition cadence represents a simple and practical index to predict and classify gait behaviour from wearable sensors in children, adolescents, and young adults. Moreover, herein we provide an equation and an open access online R Shiny app that researchers, practitioners, or clinicians can use to predict individual-specific preferred transition cadences.
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    Walking cadence (steps/min) and intensity in 41 to 60-year-old adults: the CADENCE-adults study
    (BMC, 2020) Tudor-Locke, Catrine; Ducharme, Scott W.; Aguiar, Elroy J.; Schuna, John M., Jr.; Barreira, Tiago V.; Moore, Christopher C.; Chase, Colleen J.; Gould, Zachary R.; Amalbert-Birriel, Marcos A.; Mora-Gonzalez, Jose; Chipkin, Stuart R.; Staudenmayer, John; University of North Carolina; University of North Carolina Charlotte; California State University Long Beach; University of Alabama Tuscaloosa; Oregon State University; Syracuse University; University of North Carolina Chapel Hill; University of Massachusetts Amherst
    Background In younger adults (i.e., those < 40 years of age) a walking cadence of 100 steps/min is a consistently supported threshold indicative of absolutely-defined moderate intensity ambulation (i.e., >= 3 metabolic equivalents; METs). Less is known about the cadence-intensity relationship in adults of middle-age. Purpose To establish heuristic (i.e., evidence-based, practical, rounded) cadence thresholds for absolutely-defined moderate (3 METs) and vigorous (6 METs) intensity in adults 41 to 60 years of age. Methods In this cross-sectional study, 80 healthy adults of middle-age (10 men and 10 women representing each 5-year age-group between 41 to 60 years; body mass index = 26.0 +/- 4.0 kg/m(2)) walked on a treadmill for 5-min bouts beginning at 0.5 mph and increasing in 0.5 mph increments. Performance termination criteria included: 1) transitioning to running, 2) reaching 75% of age-predicted maximum heart rate, or 3) reporting a Borg rating of perceived exertion > 13. Cadence was directly observed (i.e., hand tallied). Intensity (i.e., oxygen uptake [VO2] mL/kg/min) was assessed with an indirect calorimeter and converted to METs (1 MET = 3.5 mL/kg/min). A combination of segmented regression and Receiver Operating Characteristic (ROC) modeling approaches was used to identify optimal cadence thresholds. Final heuristic thresholds were determined based on an evaluation of classification accuracy (sensitivity, specificity, positive and negative predictive value, overall accuracy). Results The regression model identified 101.7 (95% Predictive Interval [PI]: 54.9-110.6) and 132.1 (95% PI: 122.0-142.2) steps/min as optimal cadence thresholds for 3 METs and 6 METs, respectively. Corresponding values based on ROC models were 98.5 (95% Confidence Intervals [CI]: 97.1-104.9) and 117.3 (95% CI: 113.1-126.1) steps/min. Considering both modeling approaches, the selected heuristic thresholds for moderate and vigorous intensity were 100 and 130 steps/min, respectively. Conclusions Consistent with our previous report in 21 to 40-year-old adults, cadence thresholds of 100 and 130 steps/min emerged as heuristic values associated with 3 and 6 METs, respectively, in 41 to 60-year-old adults. These values were selected based on their utility for public health messaging and on the trade-offs in classification accuracy parameters from both statistical methods. Findings will need to be confirmed in older adults and in free-living settings.
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    Walking cadence (steps/min) and intensity in 61-85-year-old adults: the CADENCE-Adults study
    (BMC, 2021) Tudor-Locke, Catrine; Mora-Gonzalez, Jose; Ducharme, Scott W.; Aguiar, Elroy J.; Schuna, John M., Jr.; Barreira, Tiago, V; Moore, Christopher C.; Chase, Colleen J.; Gould, Zachary R.; Amalbert-Birriel, Marcos A.; Chipkin, Stuart R.; Staudenmayer, John; University of North Carolina; University of North Carolina Charlotte; California State University Long Beach; University of Alabama Tuscaloosa; Oregon State University; Syracuse University; University of North Carolina Chapel Hill; University of Massachusetts Amherst
    Background: Heuristic (i.e., evidence-based, rounded) cadences of >= 100 and >= 130 steps/min have consistently corresponded with absolutely-defined moderate (3 metabolic equivalents [METs]) and vigorous (6 METs) physical activity intensity, respectively, in adults 21-60 years of age. There is no consensus regarding similar thresholds in older adults. Purpose: To provide heuristic cadence thresholds for 3, 4, 5, and 6 METs in 61-85-year-old adults. Methods: Ninety-eight community-dwelling ambulatory and ostensibly healthy older adults (age = 72.6 +/- 6.9 years; 49% women) walked on a treadmill for a series of 5-min bouts (beginning at 0.5 mph with 0.5 mph increments) in this laboratory-based cross-sectional study until: 1) transitioning to running, 2) reaching >= 75% of their age-predicted maximum heart rate, or 3) reporting a Borg rating of perceived exertion > 13. Cadence was directly observed and hand-tallied. Intensity (oxygen uptake [VO2] mL/kg/min) was assessed with indirect calorimetry and converted to METs (1 MET = 3.5 mL/kg/min). Cadence thresholds were identified via segmented mixed effects model regression and using Receiver Operating Characteristic (ROC) curves. Final heuristic cadence thresholds represented an analytical compromise based on classification accuracy (sensitivity, specificity, positive and negative predictive value, and overall accuracy). Results: Cadences of 103.1 (95% Prediction Interval: 70.0-114.2), 116.4 (105.3-127.4), 129.6 (118.6-140.7), and 142.9 steps/min (131.8-148.4) were identified for 3, 4, 5, and 6 METs, respectively, based on the segmented regression. Comparable values based on ROC analysis were 100.3 (95% Confidence Intervals: 95.7-103.1), 111.5 (106.1-112.9), 116.0 (112.4-120.2), and 128.6 steps/min (128.3-136.4). Heuristic cadence thresholds of 100, 110, and 120 were associated with 3, 4, and 5 METs. Data to inform a threshold for >= 6 METs was limited, as only 6/98 (6.0%) participants achieved this intensity. Conclusions: Consistent with previous data collected from 21-40 and 41-60-year-old adults, heuristic cadence thresholds of 100, 110, and 120 steps/min were associated with 3, 4, and 5 METs, respectively, in 61-85-year-old adults. Most older adults tested did not achieve the intensity of >= 6 METs; therefore, our data do not support establishing thresholds corresponding with this intensity level.