617 research outputs found
Reproducibility of limb power outputs and cardiopulmonary responses to exercise using a novel swimming training machine
The purpose of this study was to determine the reproducibility of limb power output and cardiopulmonary responses, to incremental whole-body exercise using a novel swimming training machine. Eight swimmers with a mean age of 23.7 ± 4.6 (yrs), stature 1.77 ± 0.13 (m) and body mass of 74.7 ± 2.8 (kg) gave informed consent and participated in repeat exercise testing on the machine. All subjects performed two incremental exercise tests to exhaustion using front crawl movements. From these tests peak oxygen consumption (VO2peak), peak heart rate (HRpeak), peak power output (Wpeak) and individual limb power outputs were determined. Results showed there were no significant differences between test 1 and 2 for any variable at exhaustion, and the CV% ranged from 2.8% to 3.4%. The pooled mean values were; VO2peak 3.7 ± 0.65 L.min-1, HRpeak 178.7 ± 6.6 b.min-1 and Wpeak 349.7 ± 16.5 W. The mean contributions to the total power output from the legs and arms were (37.3 ± 4.1 % and 62.7 ± 5.1 % respectively). These results show that it is possible to measure individual limb power outputs and cardopulmonary parameters reproducibly during whole-body exercise using this training machine, at a range of exercise intensitie
The effects of isometric exercise training on femoral and brachial artery dimension and blood flow in middle-aged men.
Introduction Previous isometric training studies reporting reductions in resting blood pressure have not explored whether there are concomitant changes in resting artery dimensions and blood flow. Furthermore, the influence of isometric training intensity on these adaptations has not been investigated. Therefore, the purpose of this study was to explore whether training-induced reductions in resting blood pressure are associated with concomitant changes in the vasculature of the trained and untrained limbs and to establish if these adaptations were intensity dependent. Methods Subjects undertook an 8 week training programme consisting of 4x2 min bilateral-leg isometric contractions 3 x per week (Wiles et al., 2010). Two groups exercised at intensities equivalent to 70% (n=10) or 85% (n=10) of their peak heart rate (%HRpeak; as established in a prior incremental test), and a third group acted as controls (n=10). Resting systolic (SBP), mean arterial (MAP) and diastolic (DBP) blood pressure was measured at baseline and post-training. Artery diameter and mean blood flow (brachial and femoral) were also measured at rest using Doppler ultrasound. Analysis of variance was used to determine whether post-training measures were significantly different to baseline. Also, baseline values were used as a covariate to account for initial resting blood pressure values. Results There were significant reductions in resting SBP (-10.8±7.9 mmHg) and MAP (-4.7±6.8 mmHg) in the 85%T group post-training and concomitant significant increases in resting femoral mean artery diameter (FMAD; 1.0±0.4 mm) and femoral mean blood velocity (FMBV; 0.68±0.83 cm/s), which resulted in increased femoral artery blood flow (FABF; 82.06±31.92 ml/min). There were no significant changes in brachial artery measures after training. Furthermore, there were no significant changes in any resting measure in the 70%T or control group. Discussion This study shows that the reductions in resting SBP and MAP observed after isometric training are associated with concomitant increases in resting artery dimensions and blood flow, but these changes were restricted to the trained limbs. This suggests that the vascular adaptations were localised. Furthermore, these adaptations seem to be training-intensity dependent, as they were not observed in the 70%T training group. These findings could be explained by reduced resting vascular tone, enhanced endothelium-dependent function or by vascular remodelling. The stimulus for such adaptations may arise from changes in availability/activity of nitric oxide as a result of sheer stresses during isometric exercise (McGowan et al. 2007). Exactly how these sheer stresses occur during isometric exercise and how they might be related to isometric training intensity would be deserving of future study. McGowan CL, Levy AS, McCartney N, MacDonald MJ. (2007). Clin. Sci. 112, 403-409. Wiles JD, Coleman DA, Swaine IL. (2010). Eur. J. Appl. Physiol. 108, 419-428
Self-management interventions to improve skin care for pressure ulcer prevention in people with spinal cord injuries: A systematic review protocol
Background: Pressure ulcers are a serious, common, lifelong, and costly secondary complication of spinal cord injury (SCI). Community-dwelling people with a SCI can prevent them with appropriate skin care (i.e. pressure relieving activities, skin checks). Adherence to skin care remains suboptimal however, and self-management interventions that focus on improving this have been designed. Little is known on their content, effectiveness, or theoretical basis. The aim of the proposed systematic review is to synthesize the literature on self-management interventions to improve skin care in people with a SCI. Specific objectives are to describe these interventions in relation to their content, effectiveness, theory base, and adherence to reporting guidelines for intervention description.
Methods: The search strategy will combine an electronic search of nine bibliographic databases (MEDLINE, Embase, PsycInfo, CENTRAL, CINAHL, Rehabdata, CIRRIE, PEDro, ERIC) and two trial registers with a manual search of relevant reference lists. Predefined eligibility criteria will be applied in a two-phase selection process involving title and abstract screening, followed by full-text screening. A data extraction spreadsheet will be applied to included papers. Intervention content will be coded using two taxonomies (behaviour change taxonomy; PRISMS self-management support taxonomy). A validated tool (Theory Coding Scheme) and the Template for Intervention Description and Replication (TIDieR) will be used to examine theoretical basis and assess adherence to reporting guidelines for intervention description. A small number of heterogeneous studies are likely to be included in this review therefore a narrative synthesis is planned.
Discussion: This systematic review will help identify the gaps and priorities to guide future research activities in this area.
Systematic review registration: PROSPERO CRD4201603319
Sustainable forest management for smallholder farmers in the Brazilian Amazon.
The paper describes a forest management system to be applied on smallholder farms, particularly on settlement projects in the Brazilian Amazon. The proposed forest management system was designed to generate a new source of family income and to maintain forest structure and biodiversity. The system is new in three main characteristics: the use of short cycles in the management of tropical forests, the low harvesting intensity and environmental impact, and the direct involvement of the local population in ali forest management activities. It is based on a minimum felling cycle of ten years and an annual timber harvest of 5-10 m3 ha-1
The relationship between EMG and either heart rate or blood pressure during a single-leg incremental isometric exercise test
Recently Wiles et al. (2008: Journal of Sports Sciences, 24, 155-162) introduced the linear relationship between double-leg EMG and either HR or BP during incremental isometric exercise as a novel method for regulating exercise intensity during training. However, many previous training studies (eg Wiley et al., 1992: Medicine and Science in Sports and Exercise, 24, 749-754) have employed single-leg protocols. The relationship between EMG and HR or BP during an incremental single-leg protocol has not been explored. Therefore, the purpose of this study was to determine whether these relationships were evident in a single-leg protocol. Following ethical approval fifteen healthy, normotensive (mean systolic blood pressure 123.8, s = 6.8 mmHg) and physically active men (age 24.8, s = 6.7 yrs; mass 78.8, s = 9.5 kg) performed a maximum voluntary contraction (MVC) using a seated isometric single-leg extension, from which peak torque (TORpeak) and EMG (EMGpeak) were determined. Subsequently, subjects performed two incremental isometric exercise tests at 10, 15, 20, 25 and 30 %EMGpeak, using dominant and non-dominant legs, during which HR and BP were measured continuously. The slope and elevation (intercept) of the linear regression lines obtained in each leg were compared with the use of analysis of covariance (ANCOVA). The within- and between-subjects variation of the mean HR, SBP, and %EMGpeak values was assessed using a repeated measures multivariate analysis of variance (MANOVA). The group mean data for each leg showed a linear relationship between %EMGpeak and HR (dominant leg r = 0.98; P0.05 and 0.98, P0.05 and 0.99, P< 0.001). The lack of a linear relationship in many individuals was probably due to the accumulation of local metabolites in the single-leg compared to the previously published double-leg isometric exercise. The inter-individual variation in the relationship between EMGpeak and HR or BP during the single-leg protocol, make it difficult to use the single-leg protocol, in the same way as the double-leg protocol, to prescribe isometric exercise intensity during training
Dissecting the difference in tree species richness between Africa and South America
peer reviewedSignificanceOur full-scale comparison of Africa and South America's lowland tropical tree floras shows that both Africa and South America's moist and dry tree floras are organized similarly: plant families that are rich in tree species on one continent are also rich in tree species on the other continent, and these patterns hold across moist and dry environments. Moreover, we confirm that there is an important difference in tree species richness between the two continents, which is linked to a few families that are exceptionally diverse in South American moist forests, although dry formations also contribute to this difference. Plant families only present on one of the two continents do not contribute substantially to differences in tree species richness
Sustainable forest management for smallholder farmers in the Brazilian Amazon.
The ecological basis for this sustainable forest management system, the components of the management system, and their application in a pilot project on smallholder farms in the pc Pedro Peixoto in Acre state in the western Brazilian Amazon are described in this chapter. Preliminary results from the pilot project on tree growth, mortality, and recruitment after an initial harvesting are also discussed
Acute response to a 2-minute isometric exercise test predicts the blood pressure lowering efficacy of isometric resistance training in young adults
This work aimed to explore whether different forms of a simple isometric exercise test could be used to predict the blood pressure (BP)-lowering efficacy of different types of isometric resistance training (IRT) in healthy young adults. In light of the emphasis on primary prevention of hypertension, identifying those with normal BP who will respond to IRT is important. Also, heightened BP reactivity increases hypertension risk, and as IRT reduces BP reactivity in patients with hypertension, it warrants further investigation in a healthy population. METHODS Forty-six young men and women (24 ± 5 years; 116 ± 10/ 68 ± 8 mm Hg) were recruited from 2 study sites: Windsor, Canada (n = 26; 13 women), and Northampton, United Kingdom (n = 20; 10 women). Resting BP and BP reactivity to an isometric exercise test were assessed prior to and following 10 weeks of thrice weekly IRT. Canadian participants trained on a handgrip dynamometer (isometric handgrip, IHG), while participants in the UK trained on an isometric leg extension dynamometer (ILE). RESULTS Men and women enrolled in both interventions demonstrated significant reductions in systolic BP (P < 0.001) and pulse pressure (P < 0.05). Additionally, test-induced systolic BP changes to IHG and ILE tests were associated with IHG and ILE training-induced reductions in systolic BP after 10 weeks of training, respectively (r = 0.58 and r = 0.77; for IHG and ILE; P < 0.05). CONCLUSIONS The acute BP response to an isometric exercise test appears to be a viable tool to identify individuals who may respond to traditional IRT prescription
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Cultural adaptation and psychometric evaluation of the Swedish version of the Reproductive Concerns After Cancer (RCAC) scale
BACKGROUND: Reproductive concerns are common among young cancer survivors and include worries related to different aspects of fertility and parenthood. The Reproductive Concerns After Cancer (RCAC) scale is an 18-item scale with six dimensions, developed to capture a variety of such concerns. The aim of the present study was to describe the cultural adaptation of the RCAC scale into Swedish and evaluate its psychometric properties among young women who have undergone treatment for cancer.
METHODS: The RCAC was forward translated from English into Swedish and assessed for cultural adaptation based on a two-panel approach followed by cognitive interviews with the target group. For the psychometric evaluation, a Swedish cohort of 181 female young adult breast cancer survivors completed a survey including the RCAC scale approximately 1.5 years post-diagnosis. Psychometric properties were examined by analyses of construct validity (confirmatory factor analysis and convergent validity), data quality (score distribution, floor and ceiling effects), reliability and known-groups validity.
RESULTS: The confirmatory factor analysis yielded an acceptable fit (RMSEA 0.08, SRMR 0.09, CFI 0.92). Convergent validity was demonstrated by a negative correlation of moderate size (- 0.36) between the RCAC total score and the emotional function scale of the EORTC QLQ-C30. Reliability measured with Revelle Ω total was satisfactory (0.73-0.92) for five of the dimensions, and poor for the dimension Becoming pregnant (Revelle Ω total = 0.60); Cronbach's alpha showed a similar pattern. Known-groups validity was indicated by significant RCAC mean score differences (MD), reflecting more concerns among women with a certain (MD 4.56 [95% CI 3.13 to 5.99]) or uncertain (MD 3.41 [95% CI 1.68 to 5.14]) child wish compared to those with no wish for (additional) children.
CONCLUSION: The translation and cultural adaptation of the Swedish RCAC has resulted in a scale demonstrating construct and known-groups validity, and satisfactory reliability for five of six dimensions. The dimension Becoming pregnant showed non-optimal internal consistency and should undergo further evaluation. The Swedish RCAC is recommended to be used in research settings for measurement of concerns related to fertility and parenthood in young women with cancer
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