Lightfoot, JT, RP Claytor, DJ Torok, TW Journell, SM Fortney. Ten week aerobic training do not affect lower body negative pressure responses . Journal of Applied Physiology. 67(2): 894-901, 1989.

Based mostly on cross-sectional data, it has been suggested that aerobic training may decrease lower body negative pressure (LBNP) tolerance through a hypothesized attenuation in both high-pressure and low-pressure baroreflex gain. An experimental group (EXP) of 8 male subjects (22.1±1.4 yrs; mean±SD) underwent a 10 week treadmill and cycle ergometer training program which resulted in a 21% increase in VO2max (45.7±1.5 ml(kg.min)-1 vs. 55.2±1.7 ml(kg.min)-1; means±SE, p<0.05). a control group, (con; n="7;" 27.3±5.7 yrs), which did not undergo training, had no significant changes in vo2max (49.4±3.3 ml(kg.min)-1 vs. 48.8±3.2 ml(kg.min)-1). pre- and post-training, the exp and con groups, participated in lbnp tolerance tests (terminated at presyncope) and neck pressure-suction testing (to describe the carotid sinus-heart rate baroreflex; br). lbnp tolerance, as defined by three different indices, and carotid sinus-heart rate baroreflex gain were not altered in either group after training. furthermore, there were no changes in lbnp heart rate, blood pressure, leg circumference, forearm blood flow, or forearm vascular resistance responses at any level of lbnp challenge after training. in conclusion, ten weeks of aerobic training did not change lbnp tolerance or alter the reflex cardiovascular compensatory mechanisms activated during lbnp.

key words:<>forearm blood flow; blood pressure; heart rate; forearm vascular resistance; LBNP tolerance