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Carotid-cardiac baroreflex response and LBNP tolerance following resistance trainingThe purpose of this study was to examine the effect of lower body resistance training on cardiovascular control mechanisms and blood pressure maintenance during an orthostatic challenge. Lower body negative pressure (LBNP) tolerance, carotid-cardiac baroreflex function (using neck chamber pressure), and calf compliance were measured in eight healthy males before and after 19 wk of knee extension and leg press training. Resistance training sessions consisted of four or five sets of 6-12 repetitions of each exercise, performed two times per week. Training increased strength 25 +/- 3 (SE) percent (P = 0.0003) and 31 +/- 6 percent (P = 0.0004), respectively, for the leg press and knee extension exercises. Average fiber size in biopsy samples of m. vastus lateralis increased 21 +/- 5 percent (P = 0.0014). Resistance training had no significant effect on LBNP tolerance. However, calf compliance decreased in five of the seven subjects measured, with the group average changing from 4.4 +/- 0.6 ml.mm Hg-1 to 3.9 +/- 0.3 ml.mm Hg-1 (P = 0.3826). The stimulus-response relationship of the carotid-cardiac baroreflex response shifted to the left on the carotid pressure axis as indicated by a reduction of 6 mm Hg in baseline systolic blood pressure (P = 0.0471). In addition, maximum slope increased from 5.4 +/- 1.3 ms.mm Hg-1 before training to 6.6 +/- 1.6 ms.mm Hg-1 after training (P = 0.0141). Our results suggest the possibility that high resistance, lower extremity exercise training can cause a chronic increase in sensitivity and resetting of the carotid-cardiac baroreflex.
Document ID
19930044699
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Tatro, D. L.
(NASA John F. Kennedy Space Center Cocoa Beach, FL, United States)
Dudley, G. A.
(NASA John F. Kennedy Space Center Cocoa Beach, FL, United States)
Convertino, V. A.
(Bionetics Corp.; NASA, Kennedy Space Center Cocoa Beach, FL, United States)
Date Acquired
August 16, 2013
Publication Date
July 1, 1992
Publication Information
Publication: Medicine and Science in Sports and Exercise
Volume: 24
Issue: 7
ISSN: 0195-9131
Subject Category
Aerospace Medicine
Accession Number
93A28696
Distribution Limits
Public
Copyright
Other

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