Journal of Applied Physiology, Vol 56, Issue 2 302-307, Copyright © 1984 by American Physiological Society
Development of cardiorespiratory function in circumpubertal boys: a longitudinal study
D. A. Cunningham, D. H. Paterson, C. J. Blimkie and A. P. Donner
To investigate cardiorespiratory function during circumpubertal growth, 62
boys (aged 9-10 yr) were studied annually for 6 yr. Measurements of O2
uptake (VO2), cardiac output, and arteriovenous O2 difference were made
during a submaximal bicycle test. Values were interpolated to a heart rate
of 155 beats X min-1 (VO2 at a heart rate of 155) for comparisons across
ages 10.8-14.8 yr. To account for growth differences among the boys, data
were also aligned at yearly intervals relative to their individual age of
peak height velocity (PHV; maturative age). The group was further divided
into early, mid, and late maturers based on their year of PHV. VO2 and
stroke volume (SV) of late maturers were larger at each maturative age. SV
mirrored the increase in VO2 at all stages of development except during the
period of most rapid growth. Arteriovenous O2 difference showed an increase
in the year of peak growth with little change during any of the other
maturative age intervals. Multiple regression analysis indicated that VO2
was determined primarily by the size of SV throughout this age range.
