Document Detail

Effects of different sprint cycling bouts on left ventricular function in top cyclists.
MedLine Citation:
PMID:  18974723     Owner:  NLM     Status:  MEDLINE    
AIM: The study investigated lactic acid and left ventricular function in response to two different sprint cycling schedules varying in their time schedule, in 15 healthy national level cyclists (23+/-1 years). METHODS: During one testing session subjects performed four strenuous bouts in a schedule of increasing time order: 1, 2, 3 and 4 min. In the other session, they performed a decreasing order: 4, 3, 2 and 1 min. Resting time between bouts in the increasing schedule were 2, 3, and 4 min, respectively. Resting times for the decreasing schedules were 4, 3 and 2 min, respectively. Exercise bouts were performed on an electrical cycle ergometer at 85% of each subject's maximal speed velocity. RESULTS: In both sprint cycling schemes, mean end-systolic volume and mean end-diastolic volume decreased significantly (P < 0.05) with bout's time. However, there was a significant interaction effect regarding schedule order and lactate accumulation. In the incremented scheme, lactate accumulated gradually during the session, while a high level of lactate was maintained throughout the decremented scheme (from 3.8+/-0.7 to 11.8+/-1.8 and from 9.5+/-1.5 to 10.8+/-1.9 mmol.L-1, respectively). Furthermore, analysis of cardiac function during the two schemes demonstrates different physiological responses. The decreasing scheme was characterized by a higher mean heart rate, a lower mean stroke volume and a lower mean end-diastolic volume (P < 0.05) indicating that during the two schemes, the functional mechanisms underlying cardiac response, are different. CONCLUSION: Our data suggest that in the face of high levels of lactic acid, during the decreasing scheme, venous return may be impeded, most likely due to reduced left ventricular filling time and inadequate vasodilatation of the arteries during the early phase of cycling bout. In addition, it suggests that the decreasing scheme may yield a better anaerobic and cardiovascular training method.
M Sagiv; M Sagiv; Y Meckel; D Ben-Sira; R Amir
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of sports medicine and physical fitness     Volume:  48     ISSN:  0022-4707     ISO Abbreviation:  J Sports Med Phys Fitness     Publication Date:  2008 Sep 
Date Detail:
Created Date:  2008-10-31     Completed Date:  2008-12-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0376337     Medline TA:  J Sports Med Phys Fitness     Country:  Italy    
Other Details:
Languages:  eng     Pagination:  360-5     Citation Subset:  IM    
Division of Sports Medicine and Rehabilitation, Zinman College of Physical Education and Sport Sciences, Wingate, Israel.
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MeSH Terms
Bicycling / physiology*
Cardiac Output / physiology*
Exercise Tolerance / physiology*
Heart / physiology*
Heart Rate / physiology*
Muscle Contraction / physiology*
Muscle, Skeletal / physiology*
Oxygen Consumption
Physical Fitness / physiology
Pilot Projects
Stroke Volume / physiology
Ventricular Function, Left / physiology*
Young Adult

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