Submitted on January 7, 2008
Accepted on May 1, 2008
Systemic arterial compliance, systemic vascular resistance, and effective arterial elastance during exercise in endurance-trained men
Takeshi Otsuki1, Seiji Maeda2*, Motoyuki Iemitsu3, Yoko Saito4, Yuko Tanimura4, Ryuichi Ajisaka4, and Takashi Miyauchi3
1 Faculty of Health and Welfare Human Services, Health and Sports Management Major, St. Catherine University, Matsuyama, Japan
2 Division of Sports Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
3 Center for Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan
4 Division of Sports Medicine, University of Tsukuba, Tsukuba, Ibraki, Japan
* To whom correspondence should be addressed. E-mail: smaeda{at}tara.tsukuba.ac.jp.
Systemic arterial compliance (C) and vascular resistance (R) regulate effective arterial elastance (Ea), an index of artery load. Increases in Ea during exercise are due primarily to reductions of C and maintain optimal ventricular-arterial coupling. Because C at rest and left ventricular functional reserve are greater in endurance-trained (ET) compared to sedentary control (SC) humans, we hypothesized that reductions of C and increases in Ea are greater in ET than SC individuals. The aim of this study was to investigate C, R, and Ea during exercise in ET and SC humans. C, R, Ea, and cardiac cycle length (T) were measured at rest and during exercise of 40, 60, and 80% maximal oxygen uptake using Doppler ultrasonography in twelve SC and thirteen ET men. C decreased in an exercise intensity-dependent manner in both groups, but its reductions were greater in ET than SC subjects. Consequently, although C at rest was greater in ET than SC group, the intergroup difference in C disappeared during exercise. Exercise-related changes in R/T were relatively slight and R/T was lower in ET than SC group both at rest and during exercise. Although Ea at rest was lower in ET than SC group, there were no intergroup differences in Ea at 40, 60, or 80% maximal oxygen uptake. We conclude that the reductions of C from rest to exercise are more marked in ET than SC humans. This may be related to the exercise-associated disappearance of the difference in Ea between ET and SC humans.
