F-28 Free Communication/Poster - Physical Activity Assessment in Adults

Abstract

Blood volume (BV) is a critical component for cardiac output. However, it is unknown if a diversity in BV can explain differences in maximal oxygen uptake (VO2max) and arterial endothelial function measured as flow mediated dilatation (FMD) in elite athletes from sports with upper or lower body work, or a combination of both. PURPOSE: To compare VO2max, BV, hemoglobin mass (Hbmass) and vascular function in highly trained endurance athletes primarily exercising with whole-body (cross-country skiing), lower-body (orienteering) and upper-body (flatwater kayak). METHODS: 17 cross-country skiers, 15 orienteers and 11 flatwater kayakers were tested for VO2max, BV, Hbmass and endothelial function in the brachial artery (measured as flow mediated dilatation; FMD). RESULTS: VO2max was significantly higher in cross-country skiers compared to orienteers (77.9±4.2 vs. 70.9±3.5 mL·min-1·kg-1 and 5.83±0.60 vs. 5.24±0.45 L·min-1, both p<0.01). BV was significantly higher in cross-country skiers and orienteers compared to kayakers, both relative to body mass (105.3±9.2 and 104.8±8.0 vs. 95.4±9.3 mL·kg-1, all p<0.05) and fat-free mass (FFM) (115.2±11.1 and 116.5±8.0 vs. 104.2±10.5 mL·kgFFM-1, all p<0.01). Cross-country skiers had significantly higher Hbmass than kayakers relative to body mass (14.2±1.4 vs. 13.0±0.8 g·kg-1, p<0.05) and FFM (15.7±1.8 vs. 14.2±1.0 g·kgFFM-1, p<0.05). Arterial diameter was significantly larger in kayakers and cross-country skiers compared to orienteers (4.22±0.36 and 4.38±0.63 vs. 3.81±0.32 mm, p<0.05), whereas FMD was similar between groups. CONCLUSION: The current study supports previous findings that cross-country skiers have higher VO2max values compared to most other endurance sports. However, since the higher VO2max did not correspond with a larger BV compared to orienteers and kayakers, the specific mechanisms related to the higher VO2max in cross-country skiers still remains unknown and whether the differences are related to the various employments of upper and lower limbs during endurance exercise in these sports.