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Harry G. Banyard, James J. Tufano, Jonathon J.S. Weakley, Sam Wu, Ivan Jukic and Kazunori Nosaka

Purpose: To compare the effects of velocity-based training (VBT) and 1-repetition-maximum (1RM) percentage-based training (PBT) on changes in strength, loaded countermovement jump (CMJ), and sprint performance. Methods: A total of 24 resistance-trained males performed 6 weeks of full-depth free-weight back squats 3 times per week in a daily undulating format, with groups matched for sets and repetitions. The PBT group lifted with fixed relative loads varying from 59% to 85% of preintervention 1RM. The VBT group aimed for a sessional target velocity that was prescribed from pretraining individualized load–velocity profiles. Thus, real-time velocity feedback dictated the VBT set-by-set training load adjustments. Pretraining and posttraining assessments included the 1RM, peak velocity for CMJ at 30%1RM (PV-CMJ), 20-m sprint (including 5 and 10 m), and 505 change-of-direction test (COD). Results: The VBT group maintained faster (effect size [ES] = 1.25) training repetitions with less perceived difficulty (ES = 0.72) compared with the PBT group. The VBT group had likely to very likely improvements in the COD (ES = −1.20 to −1.27), 5-m sprint (ES = −1.17), 10-m sprint (ES = −0.93), 1RM (ES = 0.89), and PV-CMJ (ES = 0.79). The PBT group had almost certain improvements in the 1RM (ES = 1.41) and possibly beneficial improvements in the COD (ES = −0.86). Very likely favorable between-groups effects were observed for VBT compared to PBT in the PV-CMJ (ES = 1.81), 5-m sprint (ES = 1.35), and 20-m sprint (ES = 1.27); likely favorable between-groups effects were observed in the 10-m sprint (ES = 1.24) and nondominant-leg COD (ES = 0.96), whereas the dominant-leg COD (ES = 0.67) was possibly favorable. PBT had small (ES = 0.57), but unclear differences for 1RM improvement compared to VBT. Conclusions: Both training methods improved 1RM and COD times, but PBT may be slightly favorable for stronger individuals focusing on maximal strength, whereas VBT was more beneficial for PV-CMJ, sprint, and COD improvements.

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Marcelo Toledo-Vargas, Patricio Perez-Contreras, Damian Chandia-Poblete and Nicolas Aguilar-Farias

Background: The purpose was to determine the proportion of 9- to 11-year-old children meeting the 24-hour movement guidelines (24-HMG) in a low-income town from Chile. Methods: Physical activity, sedentary behavior (recreational screen), and sleep times were measured with both questionnaire and accelerometer in 258 children from third to sixth grade. Meeting the 24-HMG was defined as having ≥60 minutes per day of moderate to vigorous physical activity, ≤2 hour day of screen time, and 9 to 11 hours of sleep per night. Compliance rates were calculated as self-reported 24-HMG, with all estimations based on questionnaires, and mixed 24-HMG, in which physical activity and sleep were determined with an accelerometer and sedentary behavior was determined with a questionnaire. Results: About 198 children (10.1 [0.8] y, range 9–11 y) provided valid data for estimating self-reported 24-HMG, and 141 for mixed 24-HMG. Only 3.2% and 0.7% met the 24-HMG when using the self-reported and mixed methods, respectively. When assessing individual recommendations, 13.1% and 3.7% of the sample were physically active based on the self-report and accelerometer, respectively. About a quarter met the sedentary behavior recommendations, while around 50% met the sleep recommendations with both self-reported and mixed methods. Conclusions: An extremely low percentage of the participants met the 24-HMG. Multicomponent initiatives must be implemented to promote healthy movement behaviors in Chilean children.

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Gina M. Besenyi, Emi B. Hayashi and Richard W. Christiana

Background: Health care providers (HCPs) promoting physical activity (PA) through programs such as Park Prescriptions (ParkRx) are gaining momentum. However, it is difficult to realize provider PA practices and program interest, and differences in program success exist by provider type (eg, primary vs secondary). This study explored HCPs’ (1) PA counseling practices, (2) knowledge/interest in ParkRx, (3) barriers and resources needed to implement PA counseling and ParkRx programs, and (4) differences in primary versus secondary HCPs. Methods: An e-survey administered in Spring/Summer 2018 to HCPs in 3 states examined study objectives. Results: Respondents (n = 278) were mostly primary (58.3%) HCPs. The majority asked about patient PA habits and offered PA counseling (mean = 5.0, SD = 1.5; mean = 4.8, SD = 1.5), but few provided written prescriptions (mean = 2.5, SD = 1.6). Providers were satisfied with their PA counseling knowledge (mean = 3.8, SD = 1.0) but not with prescribing practices (mean = 3.2, SD = 1.1). Secondary HCPs placed higher importance (P = .012) and provided significantly more written PA prescriptions (P = .005). Time was a common barrier to prescribing PA (mean = 3.4, SD = 1.2), though more so for primary HCPs (P = .000). Although few HCPs knew about ParkRx programs, 81.6% expressed interest. Access to park information and community partnerships was an important resource for program implementation. Conclusions: HCPs underutilize PA prescriptions. Despite little awareness, HCPs were interested in ParkRx programs.

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Xiaoyue Hu, Jingxian Li and Lin Wang

Twenty-four healthy adults, including 12 females and 12 males, participated in the study. Each female participant completed three trials in three different phases of one menstrual cycle, which included follicular, ovulatory, and luteal phases. The study aimed to investigate whether there is any difference in joint kinetic sense, neuromuscular coordination, and isokinetic muscle strength (a) between healthy males and females at different phases of the menstrual cycle and (b) between females at different phases of the menstrual cycle. The outcome measures included the number of jumps in the square-hop test and ankle and knee proprioception, which were assessed by an electric-driven movable frame rotated at 0.4 deg/s and isokinetic muscle strength measured by a computerized dynamometer (Biodex). For the square-hop test (p = .006), ankle dorsiflexion/plantar flexion (p < .05), knee flexion/extension (p < .05), the relative peak torque of the isokinetic muscle strength at the 60° and 180° knee flexion/extension (p < .001), and the 30° and 120° ankle plantar flexion/dorsiflexion (p < .05) between females and males showed significant differences. For the females at different phases of the menstrual cycle, significant differences were found on ankle dorsiflexion (p = .003), plantar flexion (p = .023), knee extension (p = .029), the square-hop test (p = .036), and relative peak torque of isokinetic muscle strength at 180° knee flexion (p = .029). This study demonstrated that there are sex differences in lower limb proprioception and mechanical function. Females at ovulatory and luteal phases have better lower limb proprioception than at the follicular phase.

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Tanya Tripathi, Stacey C. Dusing, Peter E. Pidcoe, Yaoying Xu, Mary S. Shall and Daniel L. Riddle

Aims: The American Academy of Pediatrics recommends “parents to incorporate supervised, awake ‘prone play’ in their infant’s routine to support motor development and minimize the risk of plagiocephaly”. The purpose of this feasibility study was to compare usual care to a reward contingency–based intervention, developed to increase prone tolerance and improve motor skills. Methods: Ten full-term infants, 3–6- months old, with poor prone tolerance were randomized to either the Education group or Reward contingency group. Each group participated in three parent education sessions and 15 intervention sessions, over the period of three weeks. Infants in the Reward contingency group used the Prone Play Activity Center, a technology developed to reinforce motor behavior of infants in prone position. Intervention frequency and parent feedback data determined the feasibility of the interventions. Results: Infants in the Reward contingency group practiced a median of 12 of the 15 anticipated intervention sessions in the Prone Play Activity Center. These infants used the device for a mean of 18 minutes per day. Parents of infants in the Education group practiced a median of 10 sessions of the 15 anticipated intervention sessions. Conclusion: The reward contingency–based intervention is feasible for use in a future clinical trial with some modifications.

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Charlotte Skau Pawlowski, Henriette Bondo Andersen and Jasper Schipperijn

Background: It remains unclear if schoolyard interventions “just” provide more opportunities for those children who are already active. The authors wanted to investigate schoolyard use and physical activity (PA) among the least-active children during recess following schoolyard renewals. Methods: An intervention study design with preresults and postresults comparison was used. Accelerometer and global positioning system data were collected at 6 Danish schools from 553 children at baseline and 439 after renewals (grades 4–9). Based on mean minutes of recess moderate to vigorous PA per child per school, the least-active children were defined as all children in the lowest activity quartile at baseline and follow-up, respectively. Results: One hundred and thirty-five children (70% girls) at baseline and 108 (76% girls) at follow-up were categorized as the least-active children. At follow-up they accumulated more time (12.1 min/d) and PA (4.4 min/d) in the schoolyard during recess compared with baseline. The difference in schoolyard PA found for the least-active children was relatively small compared with the difference for all children. Conclusions: Solely improving the physical schoolyard environment seemed to have limited impact on the least-active children’s PA. Future studies should investigate the complex interrelations between the least-active children and the entire schoolyard environment.

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Rachel Tinius, Kolbi Edens, Kim Link, M. Susan Jones, Scott Lyons, Tatum Rebelle, Kevin J. Pearson and Jill Maples

Background: The purpose of this study was to determine the impact of evidence-based educational materials and access to local resources on physical activity (PA) levels, beliefs, and motivation (including self-efficacy) regarding PA during pregnancy in a rural setting. Methods: Information on PA levels (step counts, Pregnancy Physical Activity Questionnaire) and beliefs and motivation regarding PA (main surveys: Exercise Beliefs Questionnaire, Protection Motivation Theory and Health Action Process Approach) were collected between 8 and 16 weeks gestation. Women from a rural community were randomly assigned to the PA group (PAG, n = 38) or control group (n = 32). The PAG participants received an evidence-based educational brochure and access (at no charge to them) to local fitness facilities. At approximately 34 to 37 weeks gestation, baseline assessments were repeated. Results: Sedentary time was significantly different between groups over time, with control participants increasing sedentary time and PAG participants decreasing sedentary time (P = .04). Sixteen women (42%) in the PAG utilized the resources provided (prenatal yoga being utilized most). Postintervention, there was a significant group × time interaction for Perceived Self-Efficacy scores; scores in the PAG remained consistent with baseline values, whereas scores in the control group decreased (P = .03). Conclusions: The intervention reduced sedentary time and maintained self-efficacy scores during pregnancy.

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Christiane Lange-Küttner and Ridhi Kochhar

Introduction: The Common Region Test (CRT) is useful for predicting children’s visual memory as individual object-place binding predicted better object memory while objects-region coding predicted better place memory. Aim: To test children with autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) with regards to spatial binding in the CRT. Methods: 19 children with ASD and 20 children with ADHD were gender-matched with 39 typically developing children by chronological age and with another 39 children by verbal mental age as control groups (N = 117) and tested with the CRT and Bender Gestalt test. Results: Children with ASD and ADHD showed more unsystematic coding than typically developing children. This was due to lower fine motor skills, and in children with ADHD also because of reduced verbal naming. Almost all children with ASD presented the less mature under-inclusive Type I unsystematic coding which included object-place binding, while children with ADHD showed the over-inclusive Type II unsystematic coding that was overriding the Gestalt-like properties of proximity and similarity. Conclusions: It was demonstrated that the CRT is a useful screening instrument for ASD and ADHD that shows that their spatial categorization varies in their unsystematic visuo-spatial classification due to fine motor skill deficiencies.