ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

This paper was presented as the seventh J.B. Wolffe Lecture at the Twenty-Sixth Annual Meeting of the American College of Sports Medicine in Honolulu, Hawaii, May 24–26, 1979.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

This symposium addresses the unique physiological problems, current research, future needs, and widespread applicability for research involving people experiencing five major chronic disabilities within the United States: quadriplegia, paraplegia, mental retardation, multiple sclerosis, and poliomyelitis. Each author represents ACSM members who, by their distinguished research efforts, exemplify scientists who have demonstrated their dedication to the specific needs of these populations. The papers will give a brief description of the pathophysiology of the disability and the resultant effects upon the group's acute response to exercise and their physiological adaptations to exercise programs. Each paper will include reports on the state of current research and what benefits to that group could be expected if a major research breakthrough occurred. Additionally, the papers will indicate the major research questions currently confronting each population and a brief statement about the strategy needed to resolve these questions. If applicable, the authors will address how such a model (of the specific disability/disease) could be used to better understand the able-bodied response to exercise. The purpose of this symposium, therefore, was not only to better understand the effects of exercise on persons having chronic disabilities, but from a physiological point of view, to use what we know about the response of people with chronic disabilities to better understand the able-bodied response.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Spinal cord injury below the first thoracic vertebra defines the condition of paraplegia, with common medical sequelae including impaired motor function, bone and muscle atrophy, poor myocardial function, and a general decline of physical fitness. Recently, there has been renewed interest in the role of exercise for improving the physical fitness, health, and rehabilitation potential of individuals rendered wheelchair dependent following spinal cord injury. This brief review examines the pathophysiology of paraplegia, outlines useful strategies for cardiorespiratory fitness assessment, discusses the current levels of cardiorespiratory fitness in individuals with paraplegia, and highlights a few unique responses to acute exercise in this population.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The purpose of this paper is to review the exercise physiology literature on spinal cord injured individuals with quadriplegia performing voluntary arm exercise and/or electrically stimulated leg exercise. The effects of level of injury, active muscle mass, and sympathetic dysfunction on acute physiologic adjustments during exercise testing and chronic training adaptations are discussed. Several topics for future research are suggested, including methods to achieve higher aerobic/cardiovascular fitness, reduce secondary cardiovascular/pulmonary disabilities and related health care costs, and promote health, wellness, and an active lifestyle.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Recent social policies have focused on reentering persons with mental retardation (MR) into the work force and the mainstream of society. However, as individuals with MR age, their rate of institutionalization greatly outweighs that of the general population as well as children with MR. Health care organizations have expressed serious concern about the impact of an aging population with disabilities, particularly the cost associated with institutionalization. Considering that cardiovascular disorders are more common in population with than without MR, and that physical fitness has been directly related to work productivity among individuals with MR, physical fitness and exercise training have important implications for this population. Yet, available data suggest that individuals with MR have low levels of physical fitness, a higher incidence of obesity, and may respond differently to exercise training than persons without MR. This paper reviews current knowledge of physical fitness status, impact of exercise testing and training, and identifies differences between populations with and without MR, with special emphasis on trends associated with aging. This review is limited to three physical fitness components: obesity, cardiovascular fitness, and muscular strength and endurance, as these components have been shown to impact health and well-being, and are related to work performance of persons with MR. Suggestions for future research are also provided.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Multiple sclerosis (MS) is a neurological disease characterized by a variety of potentially debilitating symptoms. The manner in which the disease affects each individual is unique; however, many individuals with MS have a normal life expectancy and remain ambulatory throughout their lives. Very little research has focused on understanding how MS affects basic physiologic responses during exercise. Four general topics have been addressed: autonomic control of heart rate (HR) and arterial blood pressure (BP), cardiorespiratory fitness, skeletal muscle function, and symptom instability under thermal stress. Abnormalities in cardiovascular reflexes have been observed in some MS individuals during quiescent testing; however, HR and BP responses during exercise have not confirmed such findings. Deficits in cardio-respiratory fitness appear to be present in moderately impaired individuals, which are not always present in minimally impaired persons. Similarly, abnormalities in skeletal muscle function have been reported in some individuals with MS, while absent in others. Training appears to improve both cardiorespiratory fitness and skeletal muscle function. Findings appear to be indirectly influenced by the level of physical impairment of the experimental sample. This factor needs to be considered in sample selection, as well as in analyzing and reporting data. Elicitation of symptoms in response to thermal stressors has been documented by several investigators using unreliable techniques to measure core temperature. The use of more valid methods during rest and exercise have not confirmed the relationship between symptoms and core temperature changes. It may be that thermal sensitivity, although typically reported by most MS individuals, is a symptom that is very unique to each individual and sample selection may have indirectly contaminated results in past research. Considerations for future research are discussed.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Poliomyelitis is an acute viral disease that attacks the brain and the ventral horn of the spinal cord. Damage to the lower motor neurons usually results in atrophy and weakness of muscle groups, perhaps paralysis and possibly deformity. A second type, bulbar poliomyelitis, infects the medulla oblongata and may result in dysfunction of the swallowing mechanism along with respiratory and circulatory distress. Minor forms of poliomyelitis result in fever, sore throat, headache, and upper body stiffness, but leave no significant atrophy or paralysis. The purpose of this paper is to review post-polio syndrome (PPS) as well as the effect of exercise on the symptoms and morphologic adaptations to PPS and where future research efforts should be directed. The most common features of PPS for over 350,000 afflicted survivors include general fatigue, weakness, and joint/muscle pain. The primary reasons for these symptoms include 1) destruction of the anterior horn cells by the polio virus, leaving fewer motor neurons to induce muscle contraction; 2) unaffected motor unit enlargement by reinnervation through terminal sprouting; and 3) defective transmission at the neuromuscular junction secondary to failure of terminal axonal sprout. Acute responses to resistive exercise suggest significant muscle strength decrements in the knee extensors compared with similar aged people without polio. However, limited training investigation indicates significant strength increases for the knee extensors following at least 6 wk of training. Acute aerobic responses also differ significantly from those observed in aged-matched control subjects. Chronic aerobic responses to limited training studies suggest significant elevations in maximal oxygen uptake. Although fatigue during physical activity may be a combination of central and peripheral factors, it is speculated that for the person with PPS the cause is more peripheral. Current and future research directed at determining the site of fatigue will result in treatment programs optimizing various exercise modalities and conservation of energy.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

When skeletal muscles are exposed to elevations in extracellular K+, they experience a significant and long-lasting increase in O2uptake. The basis for this response is unknown but may be related to an influx in extracellular Ca2+ions during sarcolemmal depolarization. The purpose of this study was to determine if altering Ca2+entry, either by removal of Ca2+from the bathing fluid or by exposing muscles to selective Ca2+-channel agonists or antagonists, would affect K+-induced respiration. Isolated frog sartorii muscles were incubated in normal Ringer's solution (R) or a modified Ringer's containing 10 or 18 mM KCl. O2uptake increased 83.7% in R+10 mM KCl and 502.2% in R+18 mM KCl. Incubation in Ca2+-free R+18 mM KCl containing Ni2+or Mg2+in place of Ca2+depressed the metabolic response to elevated K+. O2uptake increased 234.5% in R+18 mM KCl containing Ni2+and 80.6% in R+18 mM KCl containing Mg2+. Similarly, addition of the Ca2+-channel antagonists (gallopamil (D600) and diltiazem (DILT)) to R+18 mM KCl also depressed the respiratory response to elevated K+. O2uptake increased 224.2% and 133.1% in R+18 mM KCL containing D600 and DILT, respectively. Conversely, addition of the Ca2+-channel agonists (Bay K. 8644 (BAY) or palmitoyl carnitine (PC)) to R+10 mM KCl enhanced the metabolic response to elevated K+. O2uptake increased 278% and 438.9% in R+10 mM KCl containing BAY and PC, respectively. These results indicate that the stimulatory effects of elevated extracellular K+on skeletal muscle respiration are at least partially dependent on the availability of extracellular Ca2+and its subsequent entry during membrane depolarization.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Phosphorus-31 nuclear magnetic resonance spectroscopy (31P-MRS) has been used to characterize the spectral pattern of quadriceps muscle at rest for sedentaries (N= 10), sprinters (N= 12), and long-distance runners (N= 10). Intracellular pH (pHi), phosphocreatine (PCr), inorganic phosphate (Pi), phosphodiesters (PDE), adenosine triphosphate (ATP) and total phosphate (Pt), defined as the sum of the areas of PCr, PDE, Pi, and 3 times the β-ATP resonances, were obtained from all spectra. The pHi and ATP/Pt ratio were the same in the three groups of people studied. The PCr/Pi and PCr/Pt ratios were significantly lower and the Pi/Pt ratio was significantly higher for long-distance runners than for sprinters and sedentaries, while the PDE/Pt ratio was significantly lower for sprinters than for sedentaries and long-distance runners. Furthermore, the PCr concentration for sprinters and sedentaries was significantly higher and the Pi was significantly lower than for long-distance runners. The results obtained in this study can be explained by the accepted differences in fiber type composition between sprint and endurance athletes. We suggest that31P-MRS at rest could be used to monitor noninvasively the individual adaptive response to training in the metabolic characteristics of the athlete muscle fiber.

ISSN:0195-9131    

出版商:OVID    

年代:1993

数据来源: OVID