자연주의적 탐구조사(Naturalistic Inquiry)

Purpose of reviewThis review highlights recent work evaluating the relationship between exercise, physical activity and physical and mental health. Both cross-sectional and longitudinal studies, as well as randomized clinical trials, are included. Special attention is given to physical conditions, i

Exercise and well-being: a review of mental and physical health benefits associated with physical activity.

Resistance exercise has been shown to elicit a significant acute hormonal response. It appears that this acute response is more critical to tissue growth and remodelling than chronic changes in resting hormonal concentrations, as many studies have not shown a significant change during resistance training despite increases in muscle strength and hypertrophy. Anabolic hormones such as testosterone and the superfamily of growth hormones (GH) have been shown to be elevated during 15-30 minutes of post-resistance exercise providing an adequate stimulus is present. Protocols high in volume, moderate to high in intensity, using short rest intervals and stressing a large muscle mass, tend to produce the greatest acute hormonal elevations (e.g. testosterone, GH and the catabolic hormone cortisol) compared with low-volume, high-intensity protocols using long rest intervals. Other anabolic hormones such as insulin and insulin-like growth factor-1 (IGF-1) are critical to skeletal muscle growth. Insulin is regulated by blood glucose and amino acid levels. However, circulating IGF-1 elevations have been reported following resistance exercise presumably in response to GH-stimulated hepatic secretion. Recent evidence indicates that muscle isoforms of IGF-1 may play a substantial role in tissue remodelling via up-regulation by mechanical signalling (i.e. increased gene expression resulting from stretch and tension to the muscle cytoskeleton leading to greater protein synthesis rates). Acute elevations in catecholamines are critical to optimal force production and energy liberation during resistance exercise. More recent research has shown the importance of acute hormonal elevations and mechanical stimuli for subsequent up- and down-regulation of cytoplasmic steroid receptors needed to mediate the hormonal effects. Other factors such as nutrition, overtraining, detraining and circadian patterns of hormone secretion are critical to examining the hormonal responses and adaptations to resistance training.

Hormonal Responses and Adaptations to Resistance Exercise and Training

The quest to increase lean body mass is widely pursued by those who lift weights. Research is lacking, however, as to the best approach for maximizing exercise-induced muscle growth. Bodybuilders generally train with moderate loads and fairly short rest intervals that induce high amounts of metabolic stress. Powerlifters, on the other hand, routinely train with high-intensity loads and lengthy rest periods between sets. Although both groups are known to display impressive muscularity, it is not clear which method is superior for hypertrophic gains. It has been shown that many factors mediate the hypertrophic process and that mechanical tension, muscle damage, and metabolic stress all can play a role in exercise-induced muscle growth. Therefore, the purpose of this paper is twofold: (a) to extensively review the literature as to the mechanisms of muscle hypertrophy and their application to exercise training and (b) to draw conclusions from the research as to the optimal protocol for maximizing muscle growth.

/pdf/the-mechanisms-of-muscle-hypertrophy-and-their-application-544z22aglp.pdf

The mechanisms of muscle hypertrophy and their application to resistance training.

Using an integrative approach, this review highlights the benefits of resistance training toward improvements in functional status, health and quality of life among older adults. Sarcopenia (i.e. muscle atrophy) and loss of strength are known to occur with age. While its aetiology is poorly understood, the multifactorial sequelae of sarcopenia are well documented and present a major public health concern to our aging population, as both the quality of life and the likelihood of age-associated declines in health status are influenced. These age-related declines in health include decreased energy expenditure at rest and during exercise, and increased body fat and its accompanying increased dyslipidaemia and reduced insulin sensitivity. Quality of life is affected by reduced strength and endurance and increased difficulty in being physically active. Strength and muscle mass are increased following resistance training in older adults through a poorly understood series of events that appears to involve the recruitment of satellite cells to support hypertrophy of mature myofibres. Muscle quality (strength relative to muscle mass) also increases with resistance training in older adults possibly for a number of reasons, including increased ability to neurally activate motor units and increased high-energy phosphate availability. Resistance training in older adults also increases power, reduces the difficulty of performing daily tasks, enhances energy expenditure and body composition, and promotes participation in spontaneous physical activity. Impairment in strength development may result when aerobic training is added to resistance training but can be avoided with training limited to 3 days/week.

Effects of Resistance Training on Older Adults

The mechanism(s) of load-induced muscle hypertrophy is as yet unclear, but increasing evidence suggests a role for locally expressed insulin-like growth factor I (IGF-I). We investigated the effect...

https://www.physiology.org/doi/pdf/10.1152/ajpendo.2001.280.3.E383

Mechanical load increases muscle IGF-I and androgen receptor mRNA concentrations in humans

Plagiarism, aided by the emergence of massive databases of information on the World Wide Web, has become commonplace on college campuses and in business schools. Because prevention is preferable to policing, in this article the authors (a) present methods for educators to define plagiarism and educate students in appropriate citation and paraphrasing and (b) provide assignments and expectations that will minimize the need and possibility of cheating. The authors also suggest potential "red flags" as well as software and Web services that aid in investigation of possible Internet plagiarism.

Electronic Plagiarism as a College Instructor's Nightmare--Prevention and Detection

This study examined the effects of 24 wk. of resistance training on mood in healthy but sedentary older adults. 28 participants performed resistance training 3 times per week for 24 weeks. No significant differences were found in mood scores between high and variable resistance groups, and there were no significant interactions between resistance and sex or intervention, or among all three factors. For pooled data, significant improvement was found on measures of Confusion, Tension, Anger, and Total Mood Scores, although not for scores for Fatigue, Vigor, and Depression. Sex differences were found on some subscales, but no significant interactions between sex and resistance training. These findings support the effectiveness of resistance training in improving mood in healthy older adults, although further study is needed to control for effect size, as well as cohort, social, and attentional effects.

Resistance Training is Associated with Improved Mood in Healthy Older Adults

Prior positive psychologists proposed personality and spiritual growth.

Quantitative research dominates published literature in the helping professions. Mixed methods research, which integrates quantitative and qualitative methodologies, has received a lukewarm reception. The authors address the iterative separation that infuses theory, praxis, philosophy, methodology, training, and public perception and propose a dimensional viewpoint as a framework for successful integration of mixed methods research. This dimensional perspective demonstrates that mixed methods research techniques are necessary but not sufficient to study spiritual, ethical, and religious value issues. Research of career development, “best practices,” nature-nurture, and prayer illustrate weaknesses and opportunities for evaluating dimensional mixed methods approaches.

Transcending the Quantitative‐Qualitative Divide With Mixed Methods Research: A Multidimensional Framework for Understanding Congruence and Completeness in the Study of Values

Charles L. McLafferty

Papers

Mechanical load increases muscle IGF-I and androgen receptor mRNA concentrations in humans

Electronic Plagiarism as a College Instructor's Nightmare--Prevention and Detection

Resistance Training is Associated with Improved Mood in Healthy Older Adults

Prior positive psychologists proposed personality and spiritual growth.

Transcending the Quantitative‐Qualitative Divide With Mixed Methods Research: A Multidimensional Framework for Understanding Congruence and Completeness in the Study of Values