Browse

You are looking at 1 - 10 of 14,071 items for :

  • Sport and Exercise Science/Kinesiology x
Clear All
Restricted access

Richard R. Suminski, Robert J. Robertson, Fredric L. Goss, Silva Arslanian, Jie Kang, Sergio DaSilva, Alan C. Utter and Kenneth F. Metz

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.

Restricted access

Scott A. Conger, Alexander H.K. Montoye, Olivia Anderson, Danielle E. Boss and Jeremy A. Steeves

Speed of movement has been shown to affect the validity of physical activity (PA) monitors during locomotion. Speed of movement may also affect the validity of accelerometer-based PA monitors during other types of exercise. Purpose: To assess the ability of the Atlas Wearables Wristband2 (a PA monitor developed specifically for resistance training [RT] exercise) to identify the individual RT exercise type and count repetitions during RT exercises at various movement speeds. Methods: 50 male and female participants completed seven sets of 10 repetitions for five different upper/lower body RT exercises while wearing a Wristband2 on the left wrist. The speed of each set was completed at different metronome-paced speeds ranging from a slow speed of 4 sec·rep−1 to a fast speed of 1 sec·rep−1. Repeated Measures ANOVAs were used to compare the actual exercise type/number of repetitions among the seven different speeds. Mean absolute percent error (MAPE) and bias were calculated for repetition counting. Results: For each exercise, there tended to be significant differences between the slower speeds and the fastest speed for activity type identification and repetition counting (p < .05). Across all exercises, the highest accuracy for activity type identification (91 ± 1.8% correct overall), repetition counting (8.77 ± 0.17 of 10 reps overall) and the lowest MAPE (14 ± 1.7% overall) and bias (−1.23 ± 0.17 reps overall) occurred during the 1.5 sec·rep−1 speed (the second fastest speed tested). Conclusions: The validity of the Atlas Wearables Wristband2 to identify exercise type and count repetitions varied based on the speed of movement during RT exercises.

Restricted access

Artur Direito, Joseph J. Murphy, Matthew Mclaughlin, Jacqueline Mair, Kelly Mackenzie, Masamitsu Kamada, Rachel Sutherland, Shannon Montgomery, Trevor Shilton and on behalf of the ISPAH Early Career Network

Increasing population levels of physical activity (PA) can assist in achieving the United Nations sustainable development goals, benefiting multiple sectors and contributing to global prosperity. Practices and policies to increase PA levels exist at the subnational, national, and international levels. In 2018, the World Health Organization launched the first Global Action Plan on Physical Activity (GAPPA). The GAPPA provides guidance through a framework of effective and feasible policy actions for increasing PA, and requires engagement and advocacy from a wide spectrum of stakeholders for successful implementation of the proposed actions. Early career professionals, including researchers, practitioners, and policymakers, can play a major role with helping “all people being regularly active” by contributing to 4 overarching areas: (1) generation—of evidence, (2) dissemination—of key messages and evidence, (3) implementation—of the evidence-based actions proposed in the GAPPA, and (4) contributing to advocacy for robust national action plans on PA. The contribution of early career professionals can be achieved through 5 pathways: (1) research, (2) workplace/practice, (3) business, (4) policy, and (5) professional and public opinion. Recommendations of how early career professionals can contribute to the generation, dissemination, and implementation of the evidence and actions proposed by the GAPPA are provided.

Restricted access

Arthur H. Bossi, Wouter P. Timmerman and James G. Hopker

Purpose: There are several published equations to calculate energy expenditure (EE) from gas exchanges. The authors assessed whether using different EE equations would affect gross efficiency (GE) estimates and their reliability. Methods: Eleven male and 3 female cyclists (age 33 [10] y; height: 178 [11] cm; body mass: 76.0 [15.1] kg; maximal oxygen uptake: 51.4 [5.1] mL·kg−1·min−1; peak power output: 4.69 [0.45] W·kg−1) completed 5 visits to the laboratory on separate occasions. In the first visit, participants completed a maximal ramp test to characterize their physiological profile. In visits 2 to 5, participants performed 4 identical submaximal exercise trials to assess GE and its reliability. Each trial included three 7-minute bouts at 60%, 70%, and 80% of the gas exchange threshold. EE was calculated with 4 equations by Péronnet and Massicotte, Lusk, Brouwer, and Garby and Astrup. Results: All 4 EE equations produced GE estimates that differed from each other (all P < .001). Reliability parameters were only affected when the typical error was expressed in absolute GE units, suggesting a negligible effect—related to the magnitude of GE produced by each EE equation. The mean coefficient of variation for GE across different exercise intensities and calculation methods was 4.2%. Conclusions: Although changing the EE equation does not affect GE reliability, exercise scientists and coaches should be aware that different EE equations produce different GE estimates. Researchers are advised to share their raw data to allow for GE recalculation, enabling comparison between previous and future studies.

Restricted access

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.

Restricted access

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.

Restricted access

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.

Restricted access

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.

Restricted access

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.

Restricted access

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.