ORIGINAL ARTICLE   

Gazzetta Medica Italiana Archivio per le Scienze Mediche 2017 June;176(6):345-52

DOI: 10.23736/S0393-3660.16.03323-4

Copyright © 2016 EDIZIONI MINERVA MEDICA

language: English

Training state affects plasma volume response to work at similar relative intensities

William SULLIVAN ¹, Tina M. MANOS ², Bernard GUTIN ^{3, 4} ✉

¹ Department of Exercise Science & Physical Education, Montclair State University, Montclair, NJ, USA; ² Department of Kinesiology & Recreation Administration, Humboldt State University, Arcata, CA, USA; ³ Department of Movement Sciences & Education (Emeritus) Teachers College, Columbia University, New York, NY, USA; ⁴ Department of Pediatric Medicine & Physiology (Emeritus), Medical College of Georgia, Augusta, GA, USA

BACKGROUND: This study determined the difference in change in plasma volume between aerobically trained (T) and sedentary (UT) men cycling at a similar light and heavy relative metabolic work intensity.
METHODS: Eight T and eight UT men performed one continuous cycling bout, first at approximately 45% VO2 peak and then at approximately 80% VO2 peak. Blood was drawn during supine and seated rest and after 10 minutes of cycling at each workrate.
RESULTS: A repeated measures ANOVA revealed an interaction (P<0.0001) between group and intensity on VO2 such that the increase in VO2 was progressively greater from the light (26.4±1.8 vs. 16.9±2.4 mL∙min-1 ∙ kg-1 for the T and the UT group, respectively) to the heavy (46±3.6 vs. 29.1±4.3 mL ∙ min-1 ∙ kg-1 for the T and the UT group, respectively) relative intensity for the T than for the UT group. There was a main effect of training status such that, when averaged across the light and heavy relative metabolic intensities, the relative decrease in plasma volume was greater (P=0.021) in the UT (12±7.7% and 19.6±3.8%, respectively) than in the T (6.5±2.9% and 14.1±3.7%, respectively) group.
CONCLUSIONS: When cycling at similar relative metabolic work intensities, UT men exhibit greater relative decreases in plasma volume than T men. Therefore, for aerobic endurance training, UT individuals should be assigned a lighter relative metabolic work intensity than well-trained individuals.

KEY WORDS: Physical endurance - Oxygen consumption - Physical exertion