Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30,60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg ly sine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.
Richard R. Suminski, Robert J. Robertson, Fredric L. Goss, Silva Arslanian, Jie Kang, Sergio DaSilva, Alan C. Utter and Kenneth F. Metz
Aisha Chen, Sandhya Selvaraj, Vennila Krishnan and Shadnaz Asgari
Accurate and reliable detection of the onset of gait initiation is essential for the correct assessment of gait. Thus, this study was aimed at evaluation of the reliability and accuracy of 3 different center of pressure–based gait onset detection algorithms: A displacement baseline–based algorithm (method 1), a velocity baseline–based algorithm (method 2), and a velocity extrema–based algorithm (method 3). The center of pressure signal was obtained during 10 gait initiation trials from 16 healthy participants and 3 participants with Parkinson’s disease. Intrasession and absolute reliability of each algorithm was assessed using the intraclass correlation coefficient and the coefficient of variation of center of pressure displacement during the postural phase of gait initiation. The accuracy was evaluated using the time error of the detected onset by each algorithm relative to that of visual inspection. The authors’ results revealed that although all 3 algorithms had high to very high intrasession reliabilities in both healthy subjects and subjects with Parkinson’s disease, methods 2 and 3 showed significantly better absolute reliability than method 1 in healthy controls (P = .001). Furthermore, method 2 outperformed the other 2 algorithms in both healthy subjects and subjects with Parkinson’s disease with an overall accuracy of 0.80. Based on these results, the authors recommend using method 2 for accurate and reliable gait onset detection.
Priscila Tamplain, E. Kipling Webster, Ali Brian and Nadia C. Valentini
Assessment of the motor domain is a critical aspect of understanding motor development. Measurement of motor development is the baseline to understand potential delays and to promote the tools for change and improvement of this domain. This paper aims to reflect on the construct of motor development and the process of assessing motor performance. We review the use of assessments in motor development research and discuss issues of validity, reliability, sensitivity, and specificity. We appraise selected assessments, describe how the use of assessments changed over the periods of study in motor development, and examine the contemporary status of assessments and its applications. Finally, and most importantly, we provide suggestions and recommendations for future directions in the field, as well as pose important questions for researchers and practitioners to consider when selecting, using, and interpreting assessment results. In light of the contemporary view of motor development and the increasing focus on health applications, we recommend the use of screening tools, short forms, and technology, as well as encouraging the use of and more research on motor development assessments in childhood.
Akio Kubota, Alison Carver and Takemi Sugiyama
This cross-sectional study examined associations of local social engagement with walking and sitting, and whether these associations were modified by local environmental attributes. Older residents (aged 65–84 years, n = 849), recruited from a regional city in Japan, reported walking frequency, sitting time, local social engagement, and local environmental attributes. Walk Score® was also used as an environmental measure. Analysis of data from 705 participants found that engaging in community activities was significantly associated with more frequent walking, but not with prolonged sitting. Interaction analyses between social engagement and environmental attributes did not show any significant interactions, suggesting that promoting local social engagement may increase walking frequency among older adults, regardless of local environmental characteristics. Community-level social initiatives that encourage older adults to participate in local meetings, events, and activities may be an effective physical activity promotion strategy among older adults.
Kristin D. Morgan
Between-limb deficits in vertical ground reaction force (vGRF) production continue to remain years after anterior cruciate ligament rehabilitation, resulting in altered dynamic stability. However, the challenge is in identifying ways to assess this between-limb stability. This study implemented second-order autoregressive [AR(2)] modeling and its stationarity triangle to both quantitatively and visually delineate differences in dynamic stability from peak vGRF data in controls and post-anterior cruciate ligament reconstruction (ACLR) individuals during running. It was hypothesized that post-ACLR individuals would exhibit less dynamic stability than the controls, and that they would reside in a different location on the stationarity triangle, thus denoting differences in stability. The results presented supported the hypothesis that post-ACLR individuals exhibited significantly less dynamic stability than their control counterparts based on their model coefficients (AR1 P < .01; AR2 P = .02). These findings suggested that the post-ACLR individuals adopted a similar running pattern, possibly due to muscle weakness asymmetry, which was less dynamically stable and potentially places them at greater risk for injury. The ability of this approach to both quantitatively and visually delineate differences between these 2 groups indicates its potential as a return-to-sport decision tool.
Kylie McNeill, Natalie Durand-Bush and Pierre-Nicolas Lemyre
While coaches are considered at risk of experiencing burnout, there is an absence of intervention studies addressing this syndrome. The purpose of this qualitative study was to conduct a self-regulation intervention with five Canadian developmental (n = 2) and elite (n = 3) sport coaches (three men, two women) experiencing moderate to high levels of burnout and examine the perceived impact of this intervention on their self-regulation capacity and experiences of burnout and well-being. The content analysis of the coaches’ outtake interviews and five bi-weekly journals revealed that all five of them learned to self-regulate more effectively by developing various competencies (e.g., strategic planning for their well-being, self-monitoring) and strategies (e.g., task delegation, facilitative self-talk). Four of the coaches also perceived improvements in their symptoms of burnout and well-being. Sport psychology interventions individualized for coaches are a promising means for helping them manage burnout and enhance their overall functioning.
Yumeng Li, He Wang and Kathy J. Simpson
The purpose of the study was to compare the tibiofemoral contact forces of participants with chronic ankle instability versus controls during landings using a computer-simulated musculoskeletal model. A total of 21 female participants with chronic ankle instability and 21 pair-matched controls performed a drop landing task on a tilted force plate. A 7-camera motion capture system and 2 force plates were used to test participants’ lower-extremity biomechanics. A musculoskeletal model was used to calculate the tibiofemoral contact forces (femur on tibia). No significant between-group differences were observed for the peak tibiofemoral contact forces (P = .25–.48) during the landing phase based on paired t tests. The group differences ranged from 0.05 to 0.58 body weight (BW). Most participants demonstrated a posterior force (peak, ∼1.1 BW) for most duration of the landing phase and a medial force (peak, ∼0.9 BW) and large compressive force (peak, ∼10 BW) in the landing phase. The authors conclude that chronic ankle instability may not be related to the increased tibiofemoral contact forces or knee injury mechanisms during landings on the tilted surface.
Sofia W. Manta, Paula F. Sandreschi, Thiago S. Matias, Camila Tomicki and Tânia R.B. Benedetti
This study aimed to investigate the clustering patterns of physical activity, sedentary time (ST), and breaks in ST, and the association between the identified clusters at risk for metabolic syndrome associated with obesity in older adults. Participants included 212 users of community health centers in Brazil. A questionnaire about sociodemographic characteristics was used to describe the sample, and physical activity, ST, and breaks in ST were evaluated using accelerometers. Waist circumference was measured as an indicator of the risk for metabolic syndrome. A two-step cluster analysis and logistic regression analysis were conducted. The following four clusters were identified: sitters (37.7%), inactive (28.3%), active (25.5%), and all-day sitters/lightly active (8.5%). Participants in the active cluster were 60% less likely to be at risk for metabolic syndrome. This study may contribute to a comprehensive understanding of which older adult groups need more attention in the context of community health centers.
Freja Gheysen, Karel Herman and Delfien Van Dyck
Objective: To investigate whether the relationship of neighborhood environmental factors with physical activity (PA) is moderated by cognitive functioning in Belgian older adults. Methods: Seventy-one older adults completed validated questionnaires on PA and environmental perceptions, wore an accelerometer, and completed a computerized assessment of cognitive functioning. Moderated linear regression analyses were conducted in SPSS 24.0. Results: Overall cognitive functioning significantly moderated the associations of traffic safety and street connectivity with PA. Detailed analyses showed that these factors were only positively associated with PA in older adults with lower cognitive functioning. In addition, particularly, performance on tests assessing visuospatial and episodic memory moderated these associations. Discussion: Living in traffic-safe neighborhoods with short and many alternative routes might motivate older adults with lower cognitive functioning to be active. As such, the increase in PA might improve their cognitive abilities. This knowledge is crucial for health practitioners to develop effective PA promotion initiatives.
Ashley A. Hansen, Joanne E. Perry, John W. Lace, Zachary C. Merz, Taylor L. Montgomery and Michael J. Ross
Evidence for the mechanisms of change by which sport psychology interventions enhance performance is limited and treatment monitoring and outcomes measures would assist in establishing evidence-based practices. The present paper fills a gap in sport psychology literature by demonstrating the development and validation of a new measure (Sport Psychology Outcomes and Research Tool; SPORT). Study 1 described test construction and pilot item selection with 73 collegiate student-athletes. Twenty-three pilot items contributed unique variance while maintaining the original constructs and were selected from 80 initial items. In Study 2, exploratory and confirmatory factor analyses were conducted with collegiate student-athletes (n = 220), revealing a 17-item, four-factor model measuring Athlete Wellbeing, Self-Regulation, Performance Satisfaction, and Sport-Related Distress. Concurrent validity was supported through correlational analyses. Overall, results supported the SPORT as a new transtheoretical tool for monitoring effectiveness and outcomes of sport psychology interventions.