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Summary The apparent efficiency of sub-maximum exercise tends to be lower in subjects with a large aerobic power. This is probably an artefact arising from neglect of the oxygen debt in the calculation of mechanical efficiency. Changes in the extent of oxygen debt can obscure an increased skill of performance with training. Efficiency is improved by repetition of a given mode of exercise, but not by other forms of training. Habituation is greater during work than at rest, but even during work the change in pulse rate of young men does not exceed 2–5 beats/min over 5 experimental days. Habituation is lost if the test procedure is not repeated during training; this can complicate assessments of training from the response to sub-maximum exercise.  相似文献   

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Low intensity training, inactivity and resumed training in sedentary men   总被引:1,自引:0,他引:1  
The effects of a low intensity training regimen, consisting of two 7-week periods with an interspersed 8-week inactivity period were investigated in 16 sedentary men. A follow-up was made on 7 subjects after 38 additional weeks' training. Systemic as well as local effects were studied using exercise tests and leg muscle biopsies. The two 7-week training periods both resulted in a 6% increase in Vo2 max and a lowered heart rate during submaximal work. No persisting training effects were detected by exercise tests after inactivity. In skeletal muscle, however, striking differences in enzyme activity pattern and ultrastructure were observed between the two periods, indicating that some training effect of importance for muscle metabolic adaptation might have persisted during inactivity. It is suggested that such an effect might be associated with the local oxygen supply. During the 38-week training period there was a large increase in muscle metabolic capacity, but no change in maximal oxygen uptake. This separation of systemic and local training effects indicates a lack of a direct causal relationship between muscle metabolic potential and max imal oxygen uptake. It is suggested that the elevated muscle oxidative capacity is of importance for an increased endurance capacity.  相似文献   

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It is often assumed that judgment accuracy improves as clinical training and experience increase, but the few studies on this topic within neuropsychology have yielded negative findings. In an extension of prior research, we obtained information on background training and experience from a nationally representative sample of clinical neuropsychologists and had each practitioner appraise one from among a series of 10 cases. Except for a possible tendency among more experienced practitioners to overdiagnose abnormality, no systematic relations were obtained between training, experience, and accuracy across a series of neuropsychologic judgments. Comparable results were obtained when analysis was limited to the top versus bottom 20% of the sample. This and other studies raise doubt that clinical neuropsychologists train and practice under conditions conducive to experiential learning. The potential benefits of further research on experience and judgment accuracy are discussed.  相似文献   

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Psychotherapy in Mexico: practice, training, and regulation   总被引:1,自引:0,他引:1  
Psychotherapy conducted by psychologists in Mexico has a long history and shows promising developments but offers a relatively limited choice for health care recipients, especially in public facilities. Psychotherapy by psychologists occurs mainly in private practice, although it is spreading to public institutions such as hospitals and outpatient clinics. Most clinical psychologists in Mexico are trained in some type of psychodynamic approach, although the use of cognitive-behavioral treatments is spreading quickly. The probability that a patient will actually be seen by a psychologist depends mainly on such characteristics of the patient as socioeconomic status, place of residence, and insurance coverage, if any. These and other attributes of psychotherapy in Mexico are illustrated by the probable treatment of Mrs. A. Psychotherapy in Mexico continues to evolve toward both multidisciplinary work and evidence-based practices.  相似文献   

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Purpose

To compare the effects of short-term maximal (MST) vs. explosive (EST) strength training on maximal and explosive force production, and assess the neural adaptations underpinning any training-specific functional changes.

Methods

Male participants completed either MST (n = 9) or EST (n = 10) for 4 weeks. In training participants were instructed to: contract as fast and hard as possible for ~1 s (EST); or contract progressively up to 75 % maximal voluntary force (MVF) and hold for 3 s (MST). Pre- and post-training measurements included recording MVF during maximal voluntary contractions and explosive force at 50-ms intervals from force onset during explosive contractions. Neuromuscular activation was assessed by recording EMG RMS amplitude, normalised to a maximal M-wave and averaged across the three superficial heads of the quadriceps, at MVF and between 0–50, 0–100 and 0–150 ms during the explosive contractions.

Results

Improvements in MVF were significantly greater (P < 0.001) following MST (+21 ± 12 %) than EST (+11 ± 7 %), which appeared due to a twofold greater increase in EMG at MVF following MST. In contrast, early phase explosive force (at 100 ms) increased following EST (+16 ± 14 %), but not MST, resulting in a time × group interaction effect (P = 0.03), which appeared due to a greater increase in EMG during the early phase (first 50 ms) of explosive contractions following EST (P = 0.052).

Conclusions

These results provide evidence for distinct neuromuscular adaptations after MST vs. EST that are specific to the training stimulus, and demonstrate the independent adaptability of maximal and explosive strength.  相似文献   

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In many programs, the introduction of students to the community is relegated to a single practicum experience. This paper reviews one program's attempt to integrate field training more thoroughly into the curriculum. This is done by building the program around the setting features of a particular community. We describe how the basic training goals that have often been advocated but rarely achieved by community psychologists might be more broadly implemented. We outline the underlying training model, describe critical setting features, and show how the program has emphasized the features of history, empowerment, and size in the development of the curriculum. The discussion considers the assets and liabilities of programs focusing on a particular community and setting in order to illustrate the importance and difficulty of implementing field training models of this kind.  相似文献   

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Researchers have alluded the existence of "neural factors" in the expression and development of muscular strength. Candidate neural factors including motor unit recruitment, rate coding, double firing, and motor unit synchronization are discussed in this review. Aging is generally accompanied by lower motor unit discharge rates. However, both young and older adults exhibit rapid changes in muscular strength with repeated strength testing. These strength changes occur with concomitant albeit transient increase in motor unit discharge rate. These and other neural factors may contribute to the initial increase in muscular strength observed during the early phases of resistance exercise training.  相似文献   

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Advances in the medical field have increased the need to incorporate modern techniques into surgical resident training and surgical skills learning. To facilitate this integration, one approach that has gained credibility is the incorporation of simulator based training to supplement traditional training programs. However, existing implementations of these training methods still require the constant presence of a competent surgeon to assess the surgical dexterity of the trainee, which limits the evaluation methods and relies on subjective evaluation. This research proposes an efficient, effective, and economic video-based skill assessment technique for minimally invasive surgery (MIS). It analyzes a surgeon’s hand and surgical tool movements and detects features like smoothness, efficiency, and preciseness. The system is capable of providing both real time on-screen feedback and a performance score at the end of the surgery. Finally, we present a web-based tool where surgeons can securely upload MIS training videos and receive evaluation scores and an analysis of trainees’ performance trends over time.  相似文献   

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Mild exercise training, cardioprotection and stress genes profile   总被引:4,自引:0,他引:4  
To improve current knowledge of the molecular mechanisms underlying exercise-induced cardioprotection in a rat model of mild exercise training, Sprague–Dawley rats were trained to run on a treadmill up to 55% of their maximal oxygen uptake for 1 h/day, 3 days/week, 14 weeks, with age-matched sedentary controls (n = 20/group). Rats were sacrificed 48 h after the last training session. Despite lack of cardiac hypertrophy, training decreased blood hemoglobin (7.94 ± 0.21 mM vs. 8.78 ± 0.23 mM, mean ± SE, P = 0.01) and increased both plasma malondialdehyde (0.139 ± 0.005 mM vs. 0.085 ± 0.009 mM, P = 0.05) and the activity of Mn-superoxide dismutase (11.6 ± 0.6 vs. 16.5 ± 1.6 mU/μg, P = 0.01), whereas total superoxide dismutase activity was unaffected. When subjected to 30-min ischemia followed by 90-min reperfusion, hearts from trained rats (n = 5) displayed reduced infarct size as compared to controls (37.26 ± 0.92% vs. 49.09 ± 2.11% of risk area, P = 0.04). The biochemical analyses in the myocardium, which included gene expression profiles, real-time PCR, Western blot and determination of enzymatic activity, showed training-induced upregulation of the following mRNAs and/or proteins: growth-arrest and DNA-damage induced 153 (GADD153/CHOP), heme-oxygenase-1 (HO-1), cyclooxygenase-2 (Cox-2), heat-shock protein 70/72 (HSP70/72), whereas heat-shock protein 60 (HSP60) and glucose-regulated protein 75 (GRP75) were decreased. As a whole, these data indicate that mild exercise training activates a second window of myocardial protection against ischemia/reperfusion by upregulating a number of protective genes, thereby warranting further investigation in man. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

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Type 2 diabetes mellitus (T2DM) is at virtually pandemic levels world‐wide. Diabetes has been referred to as ‘a geneticist's nightmare’. However, dramatic advances in our understanding of the genetics of T2DM have occurred in the past 5 years. While endurance exercise training and increased habitual physical activity levels have consistently been shown to improve or be associated with improved T2DM‐related phenotypes, there is substantial interindividual variation in these responses. There is some evidence that T2DM‐related phenotype responses to exercise training are heritable, indicating that they might have a genetic basis. Genome‐wide linkage studies have not identified specific chromosomal loci that could account for these differences, and no genome‐wide association studies have been performed relative to T2DM‐related phenotype responses to exercise training. From candidate gene studies, there are relatively strong and replicated data supporting a role for the PPARγ Pro12Ala variant in the interindividual differences in T2DM‐related phenotype responses to training. This is a potentially important candidate locus because it affects T2DM susceptibility, has high biological plausibility and is the target for the primary pharmaceutical method for treating T2DM. Is it time to conduct a hypothesis‐driven large‐scale exercise training intervention trial based on PPARγ Pro12Ala genotype with T2DM‐related phenotypes as the primary outcome measures, while also assessing potential mechanistic changes in skeletal muscle and adipose tissue? Or would it be more appropriate to propose a smaller trial to address the specific skeletal muscle and adipose tissue mechanisms affected by the interaction between the PPARγ Pro12Ala genotype and exercise training?  相似文献   

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