4095 research outputs found
Sort by
The effect of sex and protein supplementation on protein turnover and muscle function during a 36-h military field exercise in energy deficit
No full textThis study investigated sex differences in, and the effect of protein supplementation on, whole-body protein turnover during a military field exercise. Forty-four British Army trainees (14 women) completed a 36-h field exercise. Participants consumed their habitual diet (n = 14 women [Women], protein intake 1.7 g·kg-1·d-1; n = 15 men [Men Controls], protein intake 1.6 g·kg-1·d-1) or the habitual diet and an additional 46.6 g·d-1 protein (n = 15 men [Men Protein], protein intake 2.1 g·kg-1·d-1). Total 24 h whole-body protein turnover was measured using the [15N]-glycine end-product method and muscle protein breakdown was estimated from urinary 3MH:creatinine 24 h before, during, and 96 h after field exercise. Women and Men Protein were compared with Men Controls to examine the effect of sex and protein supplementation. Whole-body protein turnover, synthesis, breakdown, and balance, and 3MH:creatinine did not differ between time-points (p ≥ 0.056). Whole-body protein balance was higher and 3MH:creatinine was lower in Women than Men Controls (all time-points, p ≤ 0.032) with no difference between sexes for other measures of protein turnover (p ≥ 0.072). Men Protein and Men Controls were not different for any outcome (p ≥ 0.060) but adjusted mean differences [95% confidence intervals] showed protein balance was 1.12 [0.28, 1.97] g·kg-1·d-1 higher in Men Protein than Men Controls during the field exercise. Women have higher whole-body protein balance than men in arduous training, likely due to higher energy balance. Protein supplementation may be effective for protecting whole-body protein balance in men
Editorial: Advancements in dietary supplements: enhancing sport performance and recovery
Full text linkIntra-individual variability in sagittal plane kinematics during indoor cycling time trial
Full text linkIntra-individual movement variability has historically been discounted as evidence of poor motor control. However, evidence now suggests that it may play a functional role in skill performance and so this study aimed to establish whether this is the case during a simulated indoor cycling time trial. Ten trained cyclists (Age = 31.90 ± 10.30 years, Height = 1.80 ± 0.10 years, Mass = 72.10 ± 9.40 kg) participated in a 10-mile (16 km) time trial while sagittal plane kinematics were captured using 3D motion capture technology. The results showed significant differences (p < 0.05) between knee–ankle and hip–knee coordination variability across pedal phases, with the knee–ankle coupling exhibiting more variability. Notably, faster cyclists demonstrated lower variability, particularly in the knee–ankle coupling, compared to slower cyclists. While no consistent relationship was found between movement variability and time trial performance across all participants, the results suggest that there may be a link between the level of intra-individual movement variability displayed by a cyclist and the time in which they were able to complete a 10-mile simulated time trial task in laboratory condition
Task difficulty promotes tactical learning but supresses the positive learning effects of autonomy and cognitive effort
Full text linkLearning conditions that provide task-relevant autonomy, and those that encourage cognitive
effort through manipulations of difficulty, have been reported to enhance skill development.
However, research is yet to directly compare these two manipulations to establish their relative
contribution to enhancing motor learning. This study used an on-screen target interception task to compare an autonomous group (self-selection of racquet size), a Challenge Point group (performance-contingent racquet size), a yoked group, and a fixed racquet size control group. Task accuracy and self-report measures of intrinsic motivation and cognitive effort were recorded at multiple time points across acquisition and at immediate, 24-h, seven-day, and 30-day retention and transfer tests. Results showed that task accuracy improved over acquisition, and remained robust across all retention tests, but no between group differences were seen. Intrinsic motivation levels decreased over acquisition, but with no between group differences observed. Participants (83, mean age 40(±12) years, 50 % male) within all groups reported consistently high cognitive effort scores, and made tactical learning choices, suggesting that high task difficulty may have suppressed the more subtle effects of autonomy and performance contingent practice. Conclusions are made regarding the variability of individual approaches to a novel task and the need to build experiments that can detect these idiosyncrasies
The effects of acute exercise on memory: considerations for exercise duration and participant body mass index
Full text linkAcute moderate-intensity exercise has been demonstrated to improve memory performance. It is less clear, however, whether the duration of acute exercise and body mass index (BMI) may moderate this effect. Thus, the purpose of this experiment was to evaluate the effects of differing exercise durations (20- and 40-minutes) on immediate and long-term memory performance, while considering BMI as a moderating factor in this exercise duration and memory performance relationship. Twenty-three young healthy adults participated in a within-subjects experiment. Participants completed four different experimental visits including either exercising at a moderate intensity (or standing on a treadmill) for 20- or 40-minutes, followed by an immediate free-recall memory assessment and then a delayed 24-hr recall. Acute moderate-intensity exercise improved memory performance, regardless of the duration of exercise. Further, long-term memory performance was greater for individuals with a higher BMI when they engaged in shorter (20 min) exercise compared to longer (40 min) exercise
The effects of familiarisation on countermovement jumps with handheld dumbbell accentuated eccentric loading in youth athletes
Full text linkThis study was used to investigate the effects of familiarisation on a countermovement jump (CMJ) performed with hand held dumbbell accentuated eccentric loading (AEL) at 20% of body mass (CMJAEL20). Twenty‐seven adolescent males performedCMJAEL20 on three separate occasions. Statistical parametric mapping (SPM) detected significant differences in normalised force‐time data between session one and two (50%–95% of movement time), two and three (47%–48%) and one and three (66%–96%), but not in velocity‐ or displacement‐time data. Propulsion mean vertical ground reaction force (vGRF) had excellent reliability (CV% upper CI95 = 5.12–9.33; ICC lower CI95 = 0.99), whereas jump height exhibited good relative reliability (ICC lower CI95 ≥ 0.94) but moderate to poor absolute reliability (CV% upper CI95 = 6.72–15.36). Unweighting time and braking time showed moderate to poor reliability (CV% upper CI95 = 14.22–37.06; ICC lower CI95 = 0.46–0.89). Mean bias between sessions was ≤ 10% for all variables according to repeated measures Bland‐Altman analysis; however, fixed bias was observed in braking mean vGRF and propulsion mean velocity. Jump height, braking mean vGRF, propulsion mean vGRF and propulsion mean velocity exhibited good to acceptable limits of agreement (LOA; ≤ 20%), whereas all other variables were classified as ‘poor’ (>20%). Proportional bias was identified in unweighting vGRF%, braking mean vGRF and braking mean velocity. These findings suggest that although more than three familiarisation sessions may be required for unweighting and braking CMJAEL20 variables, reliable propulsion data, including jump height, were observed from session one
Encountering environments through the arts: interdisciplinary embodiments, politics, and imaginaries
No full textThis edited collection of essays and artist reflections presents perspectives from arts and humanities researchers exploring how individuals and collectives engage with, relate to and experience environments. The term environment is broadly conceived in this volume and encompasses rural landscapes and nature spaces, urban and architectural sites, institutional, workplace and organisational spaces, domestic environments and public and private realms.
Exploring what it means to encounter environments through embodied, artistic and reflexive practices, the essays and reflections draw on theoretical fields of feminist posthuman discourse, new materialism, anthropology, human geography, queer studies, performing and fine arts, art and health, psychology and ecological perspectives. Drawing on dialogues emerging from discursive border crossings between disciplines, Encountering Environments through the Arts includes contributions from the fields of dance, walking practice, sonic arts, visual art, cultural and human geography, somatic movement practice, poetry and architecture. This collection offers insights and reflections on environment and experience from a range of voices – established and emerging scholars, independent researchers and practitioner‐researchers within and beyond the academy.
Providing a truly interdisciplinary range of research that centres on notions of site‐specific practice and experience, this is an invaluable contribution to performance studies and the wider field of arts and humanities. The reflective accounts and articulation of research methods and approaches make this volume ideal for undergraduate and postgraduate students as well as scholars and researchers of performance studies, dance and choreography studies, cultural studies, environmental humanities, arts and social sciences
Screens of power: ideology, domination, and resistance in informational society - book review
No full textThe ladybird plague
Full text linkA poem drawing on European folklore to explore themes of war, genocide and eco-collapse
Soldier performance management: insights from boots on ground research and recommendations for practitioners
Full text linkTheoretically, the serial measurement of biomarkers to monitor physiological responses to military training could be used to mitigate musculoskeletal injury risk and better understand the recovery status of personnel. To date, the cost and scalability of these initiatives have impeded their uptake by defence organisations. However, advances in technology are increasing the accessibility of a range of health and performance biomarkers. This paper presents a synthesises of findings from the literature and discussions with informed stakeholders to provide contextually relevant advice for future efforts to monitor military personnel, together with key considerations to ensure actionable outcomes from the data captured. The aim of this review is, therefore, twofold; first, to demonstrate how wearable devices and biomarkers have been used in defence research to assess the context-specific, occupational demands placed on personnel; and second, to discuss their potential to monitor military workloads, optimise training programming and understand soldier adaptation to multi-stressor environments