Ad. Mahon et P. Vaccaro, CARDIOVASCULAR ADAPTATIONS IN 8-YEAR-OLD TO 12-YEAR-OLD BOYS FOLLOWING A 14-WEEK RUNNING PROGRAM, Canadian journal of applied physiology, 19(2), 1994, pp. 139-150
This study examined the effects of a 14-week running program on VO(2)m
ax, as well as cardiac output (Q) and arterial-venous O-2 difference (
a-vO(2) dif) at submaximal intensities corresponding to 50 and 75% of
vO(2)max. Thirteen boys (mean age 10.6 +/- 1.2 yrs) served as experime
ntal subjects while 13 other boys of similar age (mean age 10.2 +/- 1.
2 yrs) served as controls. Mean VO(2)max in the runners increased 13%,
from 44.2 +/- 7.0 to 49.9 +/- 6.3 ml . kg(-1) . min(-1). Posttraining
VO2 during submaximal and maximal exercise was significantly (p < 0.0
5) greater in the runners than in the controls. Q and SV exhibited an
increase of 10% at each intensity, but posttraining differences betwee
n groups were not significant (p > 0.05). A-vO(2) dif increased by 8%
at 50% of VO(2)max and by 6% at 75% of VO(2)max, and was significantly
greater in the runners following training. These results indicate tha
t increases in submaximal relative VO2 in children are mediated by inc
reases in a-vO(2) dif and Q.