Cardiovascular response to lower body negative pressure (LBNP) following endurance training.
Eleven sedentary male volunteers were assigned to either an exercise (E) group (n = 6; endurance exercise for 12 weeks) or a control (C) group (n = 5; no exercise). After training, E significantly increased (p less than 0.01) their VO2max (pretraining: 37.0 +/- 2.3; posttraining: 44.6 +/- 2.5), whereas C showed no significant change. Heart rate (HR), arterial blood pressure (BP) and forearm blood flow (FBF) were measured both pre- and posttraining at rest and during 2 levels of LBNP: -10 mm Hg and -40 mm Hg. Both C and E had similar decreases in systolic BP and similar increases in HR and diastolic BP during LBNP when comparing the pre- and posttraining periods. In both groups, FBF significantly decreased during -40 mm Hg of LBNP in the pretraining period. However, after training, E had a significantly attenuated (p less than 0.05) decrease in FBF at -40 mm Hg (pretraining: -45.0 +/- 3.7%; posttraining: -29.8 +/- 3.1%). In C, there was no difference in the response of FBF to -40 mm Hg of LBNP comparing pretraining and posttraining. These findings indicate that endurance exercise training decreases the forearm vasoconstrictor response to high levels of LBNP.
Vroman
N B
NB
Exercise Physiology Laboratory, University of New Hampshire, Durham 03824.
Healy
J A
JA
Kertzer
R
R
D000328:Adult; D001794:Blood Pressure; D003664:Decompression; D005080:Exercise Test; D005542:Forearm / Q000098:blood supply; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008137:Longitudinal Studies; D008150:Lower Body Negative Pressure; D008297:Male; D010101:Oxygen Consumption; D010806:Physical Education and Training; D010807:Physical Endurance; D012039:Regional Blood Flow