摘要:

The purpose of this study was to determine the cardiopulmonary effect and CD3+CD4+lymphocyte change due to a 1 year program of moderate exercise training in five of six human immunodeficiency virus type I (HIV‐1) infected persons who had previously completed an initial 24‐week exercise training program. Mean entry CD4 count of the five was 274/(xl. Mean entry maximal oxygen consumption (VO2max) was 41 ml.kg‐1.min‐1for the five subjects. No change was observed in any measured cardiopulmonary parameter (VO2max, oxygen pulse, minute ventilation) or CD4 count in four of the five participants. The fifth participant, however, showed a profound immunologic and cardiopulmonary deterioration that preceded by less than 1 year the development of two acquired immunodeficiency syndrome‐defining illnesses. The results suggest that chronic exercise training is feasible and beneficial for those HIV‐1 persons with stable and improving CD4 counts above 200/μ1.

ISSN:1057-8315    

DOI:10.1080/15438629409511996

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor

摘要:

The purpose of this study was to determine the physical and physiologic changes induced by 9 weeks of equivalent amounts of high‐intensity running (n = 8) and cycle ergometer training (n = 8) on treadmill maximal oxygen uptake (YO2max), cycle ergometer peak VO2, a 1609 m (1.0 mile) running time, and a submaximal treadmill running VO2, heart rate, and accumulated lactate concentration in normal young men ages 25.1±1.2 years (mean±SE). Subjects began by training 4 days per week at 75 to 80% maximum heart rate (MHR) and during weeks 3 to 9 they exercised at 80 to 85% MHR. Interval training at 90 to 95% MHR was also added 2 days per week (total of 40 to 45 minutes). Both groups significantly (p≤s 0.01) improved treadmill VO2rnaxand cycle ergometer peak VO2. There was no difference in the amount of improvement between the groups on each test. For the cycle‐trained group, mean percent increases in peak VO2maximprovement on the treadmill and cycle ergometer were similar, whereas the running group mean percent change on the same tests showed a significant (p≤0.05) superior gain on the treadmill. Group mean running time significantly improved (p≤0.01) for both groups; however, a significant between‐group interaction (p≤0.05) for the 1609 m run indicated a differential effect on the magnitude of change favoring the running group. Results indicate that 9 weeks of equivalent intensity cycle training may be utilized as a substitute for running training with a relatively similar gain in treadmill‐and cycle ergometer‐tested aerobic power.

ISSN:1057-8315    

DOI:10.1080/15438629409511997

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor

摘要:

A statistically and clinically significant reduction in arterial pressure occurs following a single bout of low intensity, short duration aerobic exercise in individuals with hypertension. The reduction in arterial pressure is most often associated with a decrease in total peripheral resistance, peripheral sympathetic nerve activity, and plasma norepinephrine concentration; however, cardiac output is often elevated without a change in heart rate. The purpose of this article is to review the literature and propose a model that analyzes the components contributing to the postexercise reduction in arterial pressure. The model implicates an attenuated vascular response to catecholamine stimulation and an enhanced inhibitory cardiopulmonary reflex response. Recent evidence has shown that a single bout of dynamic exercise significantly attenuated the vasoconstrictor response to phenylephrine in an isolated aortic ring preparation and in the intact conscious rabbit and rat. This suggests that the ability of the vasculature to respond to a change in sympathetic nerve activity or catecholamine stimulus after exercise is significantly attenuated. Since the blood vessel is less responsive to catecholamine stimulation after exercise, a higher level of sympathetic nerve activity may be required to maintain arterial pressure. However, a single bout of dynamic exercise sufficient to produce postexertional hypotension also lowers both the concomitant plasma norepinephrine concentration and postganglionic muscle sympathetic nerve activity. These effects may explain the significant reduction in total peripheral resistance associated with dynamic exercise. The reduction in sympathetic activity appears to be mediated by a postexercise facilitation of inhibitory cardiopulmonary reflexes.

ISSN:1057-8315    

DOI:10.1080/15438629409511998

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor

摘要:

Aquatic exercise, including swimming, reduces the effect of body weight on limbs and joints. A combination of swimming and specific activities involving resistive devices was used in an attempt to improve strength in persons who had symptomatic weakness related to poliomyelitis. Dynamic muscular force application in selected limb movements and range of motion were measured before and after an 8‐week aquatic exercise intervention. Peak (PF) and average force (AF) were determined in the water using a differential pressure transducer attached to either the hand, foot, or a resistive device. Arm flexion, extension, adduction, abduction, and horizontal adduction and abduction along with combined hip flexion and knee extension were tested for both PF and AF Subjects were randomly assigned to experimental and control groups; complete data were available on nine experimental and four control subjects. PF and AF changes were greater (p≤0.05) for experimental compared with control for right arm flexion (PF, 96 versus 6%) and extension (PR 105 versus‐15%; AF, 76 versus‐30%), respectively. Changes were greater (p≤0.05) in experimental than control for left arm extension (PF, 88% versus 19%) and horizontal abduction (PF, 127% versus‐21%; AF, 122% versus‐17%). Aquatic exercise training in subjects with poliomyelitis disability resulted in significant dynamic strength changes of the upper body while appearing not to exacerbate symptomatic fatigue or pain.

ISSN:1057-8315    

DOI:10.1080/15438629409511999

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor

摘要:

The change in respiratory volume during exercise because of the use of different types of respiratory apparatus has previously been reported in the literature. However, to our knowledge, there has been no report of the reliability of measurement for commonly used apparatuses. The purpose of this study was to compare the reliability of the Hans Rudolph 2700 NRB valve with the Vacumed Speak‐Easy Mask II during maximal exercise testing. Eight moderately trained college‐aged women performed two maximal graded exercise tests using each apparatus. Breath‐by‐breath measurements of pulmonary variables were collected and a moving point average displayed, every 15 seconds. A MANOVA (valve×trial×subject) revealed no significant difference (p>0.05) in oxygen consumption, respiratory exchange ratio, rating of perceived exercise, minute ventilation (VE), tidal volume (Vt), or breathing frequency (fB) between the two pieces of equipment. Intraclass reliability of breath‐by‐breath measurements of VE, Vt, and fBwas higher overall at each work rate for the Hans Rudolph valve. A greater unexplained error variance was attributed to the Speak‐Easy Mask. Although no significant measured volume difference existed between the two types of apparatuses, it is recommended that in an experiment determining group mean statistics the number of subjects be increased in order to improve the reliability of the measurements.

ISSN:1057-8315    

DOI:10.1080/15438629409512000

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor

摘要:

Change in the proportion and functional activity of immune cells with exercise and training is reviewed in this article. A schema is proposed to categorize the initial event responsible for the exercise‐induced mobilization and activation of leukocytes as either mechanical or metabolic. Irrespective of the initiating event, the phenomenon of a biphasic leukocytosis after exercise, and its hormonal regulation, has been well characterized. Despite some conflicting evidence, it appears that moderate exercise may cause a modest and transient enhancement of immunity, whereas intensive exercise may suppress it. Whether these changes are of biologic significance is yet to be determined. Interpretation of these studies is complicated by large variability in experimental design and treatment. With current knowledge, the physician and coach can implement several strategies for the prevention and management of illness in the elite athlete.

ISSN:1057-8315    

DOI:10.1080/15438629409512001

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor

ISSN:1057-8315    

DOI:10.1080/15438629409512002

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor

ISSN:1057-8315    

DOI:10.1080/15438629409511995

出版商:Taylor&Francis Group    

年代:1994

数据来源: Taylor