Abstract | BACKGROUND: HYPOTHESIS: Endurance-trained runners will differ from endurance-trained swimmers in their cardiovascular responses to LBNP. METHODS: Male intercollegiate cross country runners (XC, n = 9), sprinters (SP, n = 7) and swimmers (SW, n = 12) underwent exposures to -10, -20 and -40 mm Hg LBNP. Forearm blood flow, heart rate (HR) and blood pressure were measured throughout. Maximal oxygen consumption (VO2max) was determined separately via combined arm-and-leg cycle ergometry. RESULTS: The XC were more fit than the SW and SP (VO2max = 64.5 +/- 3.5 vs. 51.7 +/- 1.9, 49.5 +/- 2.4 ml.kg-1.min-1; x +/- SEM; p < 0.05). Resting mean arterial pressure (MAP, 93 +/- 3 mm Hg) and forearm vascular resistance (FVR; 26.2 +/- 6.0 units) did not differ significantly between groups although HR was 17 +/- 3 b.min-1 higher (p < 0.05) in SW vs. SP and XC. Neither the pulse pressure, MAP, HR, nor FVR responses to the LBNP exposures differed significantly between the 3 groups. Compared to rest, pulse pressure was reduced (p < 0.05) 14% at -40 mm Hg. Similarly, HR was increased (p < 0.05) 10% at -40 mm Hg. FVR increased (p < 0.05) with each increase in LBNP becoming 91% greater at -40 mm Hg vs. rest. CONCLUSIONS: These data suggest that the cardiovascular responses to LBNP up to -40 mm Hg do not differ in chronically exercising males training with different modalities.
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Authors | M V Ioudina, W D Franke |
Journal | Aviation, space, and environmental medicine
(Aviat Space Environ Med)
Vol. 69
Issue 1
Pg. 53-7
(Jan 1998)
ISSN: 0095-6562 [Print] United States |
PMID | 9451535
(Publication Type: Comparative Study, Journal Article)
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Topics |
- Adult
- Blood Pressure
- Exercise Test
- Heart Rate
- Humans
- Hypotension, Orthostatic
(etiology, physiopathology)
- Lower Body Negative Pressure
(adverse effects)
- Male
- Oxygen Consumption
- Physical Education and Training
(methods)
- Physical Endurance
- Running
- Swimming
- Track and Field
- Vascular Resistance
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