Input and Soft-Tissue Vibration Characteristics during Sport-Specific Tasks Purpose To assess the influence of sport-specific tasks on the characteristics of input and soft-tissue vibrations. Method Triaxial accelerometers were used to quantify the input (heel cup of the shoe) and soft-tissue vibrations of the gastrocnemius medialis and vastus lateralis muscles during seven sport-specific tasks performed by 10 healthy volunteers. A wavelet analysis was used to analyze the acceleration signals in the time-frequency domain. The energy and frequency of the input and soft-tissue vibrations, as well as the transmission of energy from the input to the muscles and the damping properties of soft tissues, were computed. Results Different inputs, energy transmissions and damping properties were found between the various movements. Landings and side cuts induced the greatest input frequency and energy, as well as the greatest soft-tissue vibration energy. These tasks produced up to three times greater energy than in-line running. Positive energy transmission was found for frequencies under 50 Hz and for frequencies up to 90 Hz for some movements, indicating a possible change in the natural frequency of vibration within muscle. Only small differences in damping properties were found, which may indicate that the attenuation of the vibration was not the priority during these tasks. Conclusion Athletes are subject to greater energy impacts and vibrations during some sport-specific tasks compared to running. It may be useful to decrease such input/vibration energy via the usage of footwear or compression tools in order to limit their potential deleterious effects on the musculoskeletal system. It is therefore recommended to quantify and control the number of impacts induced by the different sport-specific tasks. Corresponding author: Robin Trama, UFR STAPS 1, 27/29 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, +33649850040, robin.trama@univ-lyon1.fr This study was financed by the European Regional Development Fund, FUI VIBRINNOV. The results of the study are presented clearly, honestly and without fabrication, falsification or inappropriate data manipulation. The results of the present study do not constitute endorsement by ACSM. None of the authors are in conflict of interest with regards to this research. Accepted for Publication: 18 July 2019. © 2019 American College of Sports Medicine

A Dual-Accelerometer System for Detecting Human Movement in a Free-living Environment Purpose Accurate measurement of various human movement behaviours are essential in developing 24-hour movement profiles. A dual accelerometer system recently showed promising results for accurately classifying a broad range of behaviours in a controlled laboratory environment. As a progressive step, the aim of this study is to validate the same dual-accelerometer system in semi free-living conditions in children and adults. The efficacy of several placement sites (e.g., wrist, thigh, back) were evaluated for comparison. Methods Thirty participants (15 children) wore three Axivity AX3 accelerometers alongside an automated clip camera (clipped to the lapel) that recorded video of their free-living environment (ground truth criterion measure of physical activity). Participants were encouraged to complete a range of daily-living activities within a two-hour timeframe. A random forest machine-learning classifier was trained using features generated from the raw accelerometer data. Three different placement combinations were examined (thigh-back, thigh-wrist, back-wrist), and their performance was evaluated using leave-one-out cross-validation for the child and adult samples separately. Results Machine learning models developed using the thigh-back accelerometer combination performed the best in distinguishing seven distinct activity classes with an overall accuracy of 95.6% in the adult sample, and eight activity classes with an overall accuracy of 92.0% in the child sample. There was a drop in accuracy (at least 11.0%) when other placement combinations were evaluated. Conclusions This validation study demonstrated that a dual accelerometer system previously validated in a laboratory setting also performs well in semi free-living conditions. Although these results are promising and progressive, further work is needed to expand the scope of this measurement system to detect other components of behaviour (e.g., activity intensity and sleep) that are related to health. Corresponding author: Tom Stewart, Auckland University of Technology, Private Bag 92006, Auckland 1142, New Zealand, Phone: +64 9 921 9999 ext 7855. E-mail: tom.stewart@aut.ac.nz AN received the 2018 AUT Human Potential Centre Fees Scholarship Award which funded the study. Participant incentives were covered using internal department funds. The results of this study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. The results of the present study do not constitute endorsement by ACSM. Competing interests. The authors declare that they have no competing interests. Accepted for Publication: 17 July 2019 © 2019 American College of Sports Medicine

Factors Associated with Persistently High Muscular Power from Childhood to Adulthood Purpose Child and adult muscular power have been shown to associate with contemporary cardiometabolic health. Muscular power typically persists (tracks) between childhood and adulthood. Few studies span childhood to adulthood, so we aimed to identify modifiable and environmental factors associated with the persistence or change in muscular power across the life course. Methods Prospective study examining 1,938 participants who had their muscular power (standing long jump distance) measured in 1985 as children aged 7-15-years and again 20-years later in adulthood (aged 26–36-years). A selection of objectively measured anthropometric characteristics (adiposity and fat-free mass), cardiorespiratory fitness (CRF), self-reported physical activity, dietary (quality and fruit, vegetable, protein intake) and sociodemographic data were available at both time-points. Muscular power was separated into thirds and participants were reported as having persistently low, decreasing, persistently moderate, increasing, or persistently high muscular power. Results Higher adiposity, lower physical activity, diet quality and socioeconomic status (SES) across the life course, and lower adult CRF were associated with persistently low muscular power. Lower adult protein intake and an increase in adiposity over time were associated with decreasing muscular power. An increase in fat-free mass was associated with a reduced probability of decreasing or persistently high muscular power, and an increased probability of increasing muscular power. Higher adult fruit intake was associated with increasing muscular power. Lower adiposity across the life course, higher adult CRF and SES, and higher child protein intake were associated with persistently high muscular power. Conclusion A healthy weight, good CRF, greater protein intake and high SES are important correlates of high muscular power maintained from childhood to adulthood. Correspondence: Brooklyn J. Fraser, Menzies Institute for Medical Research, University of Tasmania, Private Bag 23, Hobart 7001, Tasmania, Australia. E-mail: fraserbj@utas.edu.au The baseline study was supported by grants from the Commonwealth Departments of Sport, Recreation and Tourism, and Health; The National Heart Foundation; and the Commonwealth Schools Commission. The follow-up study was funded by grants from the National Health and Medical Research Council (211316), the National Heart Foundation (GOOH 0578), the Tasmanian Community Fund (D0013808) and Veolia Environmental Services. Sponsors included Sanitarium, ASICS and Target. CGM (100849), VC (100444) and SG (100446) are supported by National Heart Foundation of Australia Future Leader Fellowships. KJS is supported by NHMRC Early Career Fellowship (1072516). BJF is supported by the Patricia F Gordon Scholarship in Medical Research. Funding bodies and sponsors did not play a role in the study design, collection, analysis, or interpretation of data, in the writing of the manuscript, or the decision to submit the manuscript for publication. The authors declare no conflict of interest. The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. The results of the present study do not constitute endorsement by the American College of Sports Medicine. Accepted for Publication: 19 July 2019. © 2019 American College of Sports Medicine

Effects of Lifestyle Physical Activity on Vascular Function in Asymptomatic Peripheral Arterial Disease Purpose The purpose of this study was to examine the effects of a 12-week in-home self-monitored physical activity (PA) program targeting a combination of lifestyle physical activity program on changes in endothelial reactivity, arterial stiffness, sedentary behaviors, upright and stepping activities in individuals with asymptomatic peripheral arterial disease (APAD). Methods Participants (n = 38) with APAD (ages 52-87) were randomized to attention control, (AC) or a PA and sedentary reduction (PASR) group employing an interactive online 3-month program focusing on increasing lifestyle PA and decreasing sedentary behaviors. The ActivPal™ PA monitor was utilized to measure postural and stepping parameters. Endothelial reactivity (PAT-RHI) and augmentation index (AIx) were measured using the EndoPAT™ system at baseline and 3 months. Results The PASR group significantly decreased daily sit/lie hours (-0.80 ± 0.87 vs. 0.18 ± 0.77 p= 0.001), increased sit to stand transitions/day (7.1 ±10.5 vs. -1.4 ± 5.71, p<0.001) and increased daily step counts (2814 ± 1753 vs. 742 ± 1321, p <0.001). The PASR group also increased steps/day accumulated within specific cadence bands 61-80 steps/min, (1252 ± 447 vs. 177 ± 359, p <0.001), 81-100 steps/min band, (919 ± 511 vs. -98 ± 697, p <0.001), and within the 101-120 steps/min band (415 ± 625 vs. -327 ± 467, p <0.001) versus the AC group. PAT-RHI significantly increased in the PASR group (0.179 ±0.180 vs .0.044 ±0.101, p = 0.019) while no significant changes were observed in PAT-AIx. Conclusions Modest improvements in microvascular reactivity, physical activity, sedentary behavior, but not arterial stiffness were demonstrated following a 12-week intervention targeting sedentary behavior reduction and increased lifestyle PA in individuals with APAD. Address for correspondence. Steve Laslovich, PT, DPT, CPed, PhD, University of St. Augustine for Health Sciences, 700 Windy Point Drive, San Marcos, California 92069; E-mail: slaslovich@usa.edu; Phone: 760 994-3576 This research was supported in part by the University of St. Augustine for Health Sciences, San Marcos, California. There are no actual or potential conflicts of interest for any of the authors. The results of this study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. The results of the present study do not constitute endorsement by ACSM. Accepted for Publication: 18 July 2019. © 2019 American College of Sports Medicine

Physical Activity Is Higher in Patients with LVADs Compared to Chronic Heart Failure Purpose Left ventricular assist devices (LVADs) are associated with an increased aerobic capacity in patients with chronic heart failure (CHF). However, studies evaluating the impact of LVAD implantation on physical activity (PA) are lacking. The aim of this study was to compare daily PA levels in participants with LVADs with well-matched CHF participants. Methods Sixteen participants with an LVAD (age: 59.1 ± 10.8 years) were case-matched to 16 participants with advanced CHF (age: 58.3 ± 8.7 years), who were listed or being considered for cardiac transplantation. Participants underwent a cardiopulmonary exercise test to determine peak oxygen consumption (V[Combining Dot Above]O2 peak). PA was monitored continuously for seven consecutive days with an Actiheart monitor. Results V[Combining Dot Above]O2 peak in the CHF group (12.3 ± 3.5 ml·kg-1·min-1) was not significantly different to the LVAD group prior to LVAD implantation (10.4 ± 2.1 ml·kg-1·min-1), but was lower than in the LVAD group following implantation (15.8 ± 4.3 ml·kg-1·min-1; p < 0.05). PA was higher in the LVAD (19.7 ± 6.4 kJ·kg-1·day-1) compared with the CHF group (11.6 ± 6.9 kJ·kg-1·day-1; p = 0.001). LVAD participants spent more time performing moderate intensity PA than their CHF counterparts, 26 (24-40) [median (IQR)] vs. 12 (9-16) min/day; p < 0.001. PA was correlated with V[Combining Dot Above]O2 peak (r = 0.582; p = 0.001) across participants in the CHF and LVAD groups. Conclusion Higher levels of PA were observed in participants with LVAD compared with patients with advanced CHF. This may be due to a higher V[Combining Dot Above]O2 peak, resulting in an improved capacity to perform activities of daily living with less symptoms. Corresponding Author: Associate Professor Andrew Maiorana, School of Physiotherapy and Exercise Science, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Telephone: +618 9266 9225, Email: A.Maiorana@curtin.edu.au This project was supported by a Heart Foundation of Australia Vanguard Grant (101040). IMS was supported by a PhD Scholarship funded by the Heart and Lung Transplant Foundation of Western Australia and Curtin University. Conflict of Interest. Authors declare that there are no conflicts of interest. The results of the present study do not constitute endorsement by ACSM and are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. Accepted for Publication: 8 July 2019 © 2019 American College of Sports Medicine

Changes in Fatigue Are the Same for Trained Men and Women after Resistance Exercise Purpose To measure changes in fatigue and knee-extensor torque in the 48H after trained men and women completed a full-body resistance exercise session. Methods Eight trained women (mean ± SD; age, 25.6 ± 5.9 years; height, 1.68 ± 0.06 m; mass, 71.0 ± 8.6 kg) and eight trained men (age, 25.5 ± 6.2 years; height, 1.79 ± 0.05 m; mass, 86.4 ± 9.8 kg) performed a full-body resistance exercise session based on real-world athletic practice. Measurements were performed before and after the exercise session, as well as 1H, 24H, and 48H after the session. Fatigue and pain were measured with standardized self-report measures. Maximal isometric contractions with the knee-extensors and superimposed femoral nerve stimulation was performed to examine maximal torque, rate of torque development, voluntary activation, and muscle contractility. Two sets of 10 isokinetic contractions (60°.s-1) with the knee extensors were performed during the protocol with use of near-infrared spectroscopy to assess muscle oxygenation. Electromyograms (EMG) were recorded from two quadriceps muscles during all isometric and isokinetic contractions. Results Fatigue was increased from baseline for both sexes until 48H after training (p<0.001). Maximal torque and evoked twitch amplitudes were similarly reduced after exercise for men and women (p<0.001). Voluntary activation and EMG amplitudes were unchanged after the training session. Muscle oxygenation was 13.3 ± 17.4 % (p=0.005) greater for women during the isokinetic repetitions, and the values were unchanged after the training session. Conclusions This is the first study to show similar changes in the fatigue reported by trained men and women in the 48H after a training session involving full-body resistance exercises. Sex differences in muscle oxygenation during exercise do not influence the reductions in muscle force, activation, or contractility after the training session. Corresponding Author: Jason C. Siegler, j.siegler@westernsydney.edu.au, School of Science and Health, Locked Bag 1797 Penrith South, NSW 2751, AUSTRALIA. Tel: +61 4620 3915 This project did not receive any funding and the authors report no conflicts of interest. The results of the present study do not constitute endorsement by ACSM. The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. Accepted for Publication: 16 July 2019. © 2019 American College of Sports Medicine

Acute Soy Supplementation Improves 20-km Time Trial Performance, Power, and Speed INTRODUCTION Isoflavones, a chemical class of phytoestrogens found in soybeans and soy products, may have biological functions similar to estradiol. After binding with ERβ or perhaps independently of estrogen receptors, isoflavones may augment vascular endothelial relaxation, contributing to improved limb blood flow. PURPOSE To determine if acute fermented soy extract supplementation influences 20-km time trial cycling performance and cardiac hemodynamics compared to a placebo. METHODS Subjects included twenty-five cyclists and triathletes (31 ± 8 y, VO2peak: 55.1 ± 8.4 mL·kg-1·min-1). Each subject completed a VO2peak assessment, familiarization, and two 20-km time trials in randomized order following ingestion of a fermented soy extract supplement or placebo. The fermented soy extract consisted of 30 g powdered supplement in 16 fl. ounces of water. The placebo contained the same quantities of organic cocoa powder and water. Each trial consisted of 60 min of rest, 30 min at 55% Wpeak, and a self-paced 20-km time trial. RESULTS Soy supplementation elicited a faster time to 20km completion (-0.22 ± 0.10 min; -37 s), lower average heart rate (-5 ± 1 bpm), and significantly greater power (7 ± 3 W) and speed (0.42 ± 0.16 km•h-1) during the last 5 km of the time trial compared to placebo. Analysis of the results by relative fitness level (< 57 vs. ≥ 57 mL⋅kg-1⋅min-1) indicated that those with a higher level of fitness reaped the largest performance improvement alongside a reduced heart rate (-5 ± 7 bpm). CONCLUSION Ingestion of a fermented soy extract supplement improved sprint-distance performance through improvements in both power and speed. For those with great aerobic fitness, soy supplementation may help to decrease cardiac demand alongside performance improvement. Address for correspondence: Afton Seeley, MS, Department of Kinesiology and Sport Science, University of Miami, 5202 University Dr. Merrick Bldg Room 315, Coral Gables, FL 33146. Email: ads129@miami.edu The authors disclose that funding was received from BESO Biological Research, Inc. Diamond Bar, CA 91765 to support this investigation. The authors declare that the results of the study are presented clearly, honestly, and without fabrication, or inappropriate data manipulation in any way to intentionally portray anything but those outcomes that were empirically observed. The authors do not have any conflicts of interest to report. The results of the study do not constitute endorsement by the American College of Sports Medicine. Accepted for Publication: 9 July 2019. © 2019 American College of Sports Medicine

Athlete-Opponent Interdependency Alters Pacing and Information-seeking Behavior PURPOSE The influence of interdependency between competitors on pacing decision-making and information-seeking behavior has been explored. This has been done by only altering instructions, and thereby action possibilities, while controlling environment (i.e. competitor behavior) and exercise task. METHODS Twelve participants performed a 4-km time-trial on a Velotron cycle ergometer in a randomized, counterbalanced order alone with no virtual opponent (NO), against a virtual opponent with no restrictions (low athlete-opponent interdependency; OP-IND), or against a virtual opponent who the participant was permitted to overtake only once during the trial (high athlete-opponent interdependency; OP-DEP). Information-seeking behavior was evaluated using an SMI Eye tracker. Differences in pacing, performance and information-seeking behavior were examined using repeated-measures ANOVA (p<0.05). RESULTS Neither mean power output (NO: 298±35W; OP-IND: 297±38W; OP-DEP: 296±37W) nor finishing time (NO: 377.7±17.4sec; OP-IND: 379.3±19.5sec; OP-DEP: 378.5±17.7sec) differed between experimental conditions. However, power output was lower in the first kilometer of OP-DEP compared to the other experimental conditions (NO: 332±59W; OP-IND: 325±62W; OP-DEP: 316±58W; both p<0.05), and participants decided to wait longer before they overtook their opponent (OP-IND: 137±130sec; OP-DEP: 255±107sec; p=0.040). Moreover, total fixation time spent on the avatar of the virtual opponent increased when participants were only allowed to overtake once (OP-IND: 23.3±16.6sec; OP-DEP: 55.8±32.7sec; p=0.002). CONCLUSION A higher interdependency between athlete and opponent altered pacing behavior in terms of in-race adaptations based on opponent’s behavior, and induced an increased attentional focus on the virtual opponent. Thus, in the context of exercise regulation, attentional cues are likely to be used in an adaptive way according to their availability and situational relevance, consistent with a decision-making framework based on the interdependence of perception and action. Corresponding Author: Prof Dr Florentina J Hettinga PhD SFHEA FECSS FACSM, Department of Sport, Exercise & Rehabilitation, Northumbria University, Newcastle Upon Tyne, NE1 8ST, United Kingdom No funding was received for the present study. The authors declare no conflicts of interest. The results of the present study do not constitute endorsement by ACSM. The authors declare that the results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. Accepted for Publication: 15 July 2019 © 2019 American College of Sports Medicine

High-Altitude Acclimatization Improves Recovery from Muscle Fatigue Purpose We investigated the effect of high-altitude acclimatization on peripheral fatigue compared to sea level and acute hypoxia. Methods At sea level (350 m), acute hypoxia (environmental chamber), and chronic hypoxia (5050 m, 5-9 days) (partial pressure of inspired oxygen = 140, 74 and 76 mmHg, respectively), 12 participants (11 in chronic hypoxia) had the quadriceps of their dominant leg fatigued by 3 bouts of 75 intermittent electrically-evoked contractions (12 pulses at 15 Hz, 1.6 s between train onsets, and 15 s between bouts). The initial peak force was ~30% of maximal voluntary force. Recovery was assessed by single trains at 1, 2, and 3 min post-protocol. Tissue oxygenation of rectus femoris was recorded by near-infrared spectroscopy. Results At the end of the fatigue protocol, the impairments of peak force and peak rates of force development and relaxation were greater (all P < 0.05) in acute hypoxia (~51, 53 and 64%, respectively) than sea level (~43, 43 and 52%) and chronic hypoxia (~38, 35 and 48%). Peak force and rate of force development recovered faster (P < 0.05) in chronic hypoxia (pooled data for 1-3 min: ~84 and 74% baseline, respectively) compared to sea level (~73 and 63% baseline) and acute hypoxia (~70 and 55% baseline). Tissue oxygenation did not differ among conditions for fatigue or recovery (P > 0.05). Conclusion Muscle adaptations occurring with chronic hypoxia, independent of other adaptations, positively influence muscle contractility during and after repeated contractions at high altitude. Correspondence: Dr. Chris McNeil, School of Health and Exercise Sciences, Faculty of Health and Social Development, The University of British Columbia – Okanagan Campus, 1147 Research Road, Kelowna, British Columbia, Canada, V1V 1V7. E-mail: chris.mcneil@ubc.ca, Tel.: +1-250-807-9664, Fax: +1-250-807-9865 The authors declare that they have no conflict of interest. The results of this study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation and do not constitute endorsement by the American College of Sports Medicine. This work was supported by the Natural Sciences and Engineering Research Council of Canada (DG 435912-2013) and the Canada Foundation for Innovation / British Columbia Knowledge Development Fund (32260). Accepted for Publication: 16 July 2019. © 2019 American College of Sports Medicine

Muscle Glycogen Content during Endurance Training under Low Energy Availability Purpose The present study investigated the effects of 3 consecutive days of endurance training under conditions of low energy availability on the muscle glycogen content, muscle damage markers, endocrine regulation, and endurance capacity in male runners. Methods Seven male long-distance runners [19.9 ± 1.1 years, 175.6 ± 4.7 cm, 61.4 ± 5.3 kg, maximal oxygen uptake (V·O2max): 67.5 ± 4.3 ml/kg/min] completed two trials consisting of 3 consecutive days of endurance training under low energy availability (LEA, 18.9 ± 1.9 kcal/kg FFM/day) or normal energy availability (NEA, 52.9 ± 5.0 kcal/kg FFM/day). The order of the two trials was randomized, with a 2-week interval between trials. The endurance training consisted of 75 min of treadmill running at 70% of V·O2max. Muscle glycogen content, respiratory gas variables, and blood and urine variables were measured in the morning during 3 consecutive days of training (days 1–3) and on the following morning after training (day 4). As an indication of endurance capacity, time to exhaustion at 19.0 ± 0.8 km/h to elicit 90% of V·O2max was evaluated on day 4. Results During the training period, body weight, fat-free mass, and skeletal muscle volume were significantly reduced in LEA (P = 0.02 for body weight and skeletal muscle volume, P = 0.01 for fat-free mass). Additionally, muscle glycogen content was significantly reduced in LEA (~30%, P < 0.001), with significantly lower values than those in NEA (P < 0.001). Time to exhaustion was not significantly different between the two trials (~20 min, P = 0.39). Conclusion Three consecutive days of endurance training under low energy availability decreased muscle glycogen content with lowered body weight. However, endurance capacity was not significantly impaired. Corresponding author: Kazushige Goto, Ph. D. Professor, Graduate school of Sport and Health Science, Ritsumeikan University 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577, Japan E-mail: kagoto@fc.ritsumei.ac.jp Phone: +81-77-599-4127 Fax: +81-77-599-4127 The present study was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science, and research grant from Ritsumeikan University, and the research project of Japan Institute of Sports Sciences for prevention of fatigue and recovery. The authors declare no conflicts of interest. We declare that the results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation and do not constitute endorsement by the American College of Sports Medicine. Accepted for Publication: 15 July 2019 © 2019 American College of Sports Medicine