Document Detail

Effects of short-term training on cardiac function during prolonged exercise.
MedLine Citation:
PMID:  2402209     Owner:  NLM     Status:  MEDLINE    
To determine the relationship between the training-induced increases in plasma volume (PV) and alterations in cardiac performance during prolonged submaximal cycle exercise, seven male subjects were studied prior to and following a short-term (3 d) training period (2 h.d-1 at 65% VO2max). Mean (range) VO2max was 3.42 l.min-1 (2.96-3.87). Training resulted in a 20% increase (P less than 0.05) in plasma volume (PV) and a 12% increase (P less than 0.05) in total blood volume (TBV). In contrast, training had no effect (P greater than 0.05) in altering exercise VO2, VCO2, VE BTPS, or RER. Cardiac output (Q) was higher (P less than 0.05) posttraining at all exercise sampling times (30, 60, 90, and 120 min). The elevations in Q were accompanied by an average decrease (P less than 0.05) in stroke volume (SV) of 22 ml. Arteriovenous O2 (a-v O2) difference was depressed (P less than 0.05) during exercise following the training. Although elevations (P less than 0.05) in core temperature (degrees C) occurred during the exercise, the training-induced PV increases did not affect thermoregulatory behavior. These results indicate that an early adaptive response to exercise training is an elevation in Q, an increase in SV, and a reduction in HR. These effects persist during prolonged exercise in spite of the progressive increase in body heat content. It is proposed that the increase in Q serves primarily to increase muscle blood flow and maintain arterial O2 delivery, while the altered cardiodynamic behavior serves to increase cardiac reserve, providing a greater tolerance to prolonged heavy exercise.
H J Green; L L Jones; D C Painter
Related Documents :
9493679 - Exercise training in copd patients: the basic questions.
12043719 - Short-term physical training improves vasodilatory capacity in cardiac patients.
11740299 - Hypovolemic intolerance to lower body negative pressure in female runners.
11606019 - Endurance training under 2500-m hypoxia does not increase myoglobin content in human sk...
11673769 - Resting leptin responses to acute and chronic resistance training in type 2 diabetic me...
9916179 - The gas transporting systems: limits and modifications with age and training.
2403869 - Circulatory regulation at rest and exercise and the functional assessment of patients w...
3840999 - Co-release of neuropeptide y and catecholamines during physical exercise in man.
14143679 - Venous stasis and forearm exercise during venipuncture as sources of error in plasma el...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  22     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  1990 Aug 
Date Detail:
Created Date:  1990-10-23     Completed Date:  1990-10-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  488-93     Citation Subset:  IM; S    
Department of Kinesiology, University of Waterloo, Ontario, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Cardiac Output / physiology
Exercise / physiology*
Heart / physiology*
Heart Rate / physiology
Physical Education and Training*
Plasma Volume / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Serial gastric emptying studies: effect of preceding drinks.
Next Document:  Exercise intensity-related responses of fibrinolytic activity and vasopressin in man.