Physical Fitness and Performance
Predicted maximal aerobic power in youth is
related to age, gender, and ethnicity
ROBERT G. MCMURRAY, JOANNE S. HARRELL, CHYRISE B. BRADLEY, SHIBING DENG, and
SHRIKANT I. BANGDIWALA
Department of Exercise and Sport Science, School of Nursing, and Department of Biostatistics, University of North
Carolina, Chapel Hill, NC
ABSTRACT
MCMURRAY, R. G., J. S. HARRELL, C. B. BRADLEY, S. DENG, and S. I. BANGDIWALA. Predicted maximal aerobic power in
youth is related to age, gender, and ethnicity. Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 145–151. Purpose: To determine the
effects of age, gender, and ethnicity on the predicted aerobic power of youth as they age from 8 to 16 yr. Methods: The sample was
a multicohort group of 2540 African Americans (N = 543) and Caucasians (N = 1997), 1279 (50.4%) girls and 1261 (49.6%) boys.
Heights, weights, and sum of skin folds (triceps + subscapular) were measured. Aerobic power (
p
V
˙
O
2max
), expressed in relative
(mL·kg
-1
·min
-1
) or absolute (L·min
-1
) terms, was predicted from a three-stage cycle ergometry test. Results: Quadratic mixed-model
analysis indicated that boys had higher relative and absolute
p
V
˙
O
2max
than the girls (P = 0.0004). The African American subjects had
a higher absolute
p
V
˙
O
2max
(L·min
-1
) than the Caucasians, but their relative
p
V
˙
O
2max
was lower than the Caucasians (P = 0.031).
Finally, age had a significant effect on
p
V
˙
O
2max
(P = 0.0001). The absolute
p
V
˙
O
2max
of the girls increased 9%·yr
-1
until age 14; but
their relative
p
V
˙
O
2max
declined ~ 1.2 mL·kg
-1
·min
-1
·yr
-1
. The absolute
p
V
˙
O
2max
for the boys increased yearly by ~ 14% from ages
8 to 16 yr, but the relative
p
V
˙
O
2max
of the African American males was stable from ages 8 to 11, then dropped, and stabilized again
between ages 12 and 16 yr. The relative
p
V
˙
O
2max
of the Caucasian boys declined from ages 8 to 10, but then increased slightly from
age 12 to 16 yr. In addition, the interactions of age and gender, and age squared and gender were significant (P 0.02). Conclusion:
These data indicate that although absolute
p
V
˙
O
2max
(L·min
-1
) increases from age 8 to 16 yr, relative
p
V
˙
O
2max
(mL·kg
-1
·min
-1
)
declines. The decline appears to be related to increased fat mass. Similarly, the higher relative
p
V
˙
O
2max
(mL·kg
-1
·min
-1
) of the
Caucasian youth compared with the African American youth was related to lower weights and skin folds of the Caucasian youth. Key
Words: CHILDREN, ADOLESCENTS, EXERCISE CAPACITY, V
˙
O
2max
C
ross-sectional studies have shown that maximal aer-
obic power (V
˙
O
2max
), expressed in either absolute
terms (L·min
-1
) or relative to body weight
(mL·kg
-1
·min
-1
), increases until midadolescence (12–15
yr) and then declines with increasing age (12,20,21,25,32).
Furthermore, both absolute and relative aerobic power of
girls (6 –12 yr) appear to be about 10% to 25% lower than
the boys (12,25) and peaks earlier in girls compared with
boys; 12 to 13 yr versus 18 to 19 yr, respectively (1). In
contrast to the above, Astrand (4) and Wilmore and Sigers-
eth (33) independently noted that relative V
˙
O
2max
of girls
was greatest at about age 7 to 9 yr and declined thereafter,
whereas Shephard et al. (26) noted that the predicted relative
aerobic power of boys was lower at ages 12 to 13 yr than at
ages 9 to 10 yr. Furthermore, Washington et al. (32) found
that although the absolute and relative V
˙
O
2max
of girls was
lower than for boys, there were no age-related differences in
the relative V
˙
O
2max
of 7- to 13-yr-old youth. Thus, there are
considerable inconsistencies in the literature. Although
these data reflect age-related changes, the cross-sectional
design of these studies may not reflect the true changes in
aerobic power that occur as youth age. In addition, random-
ization did not appear to occur; thus, the samples may not
represent the true population norms. Therefore, a longitu-
dinal study is necessary to determine age-related changes.
Pivarnik et al. (19) measured relative aerobic power in
adolescent African American girls and suggested that their
V
˙
O
2max
was about 14% lower than expected for non-Afri-
can American female adolescents. However, their study
included only 64 African American girls aged 11 to 16 yr,
and the authors did not attempt to determine at what age the
differences first appear. However, the research of Trow-
bridge et al. (30), using 44 African American and 31 Cau-
casian prepubertal youth, suggests that the ethnic differ-
ences exist as early as age 5 yr. Like the study of Pivarnik
et al., this study had a fairly small sample, limiting the
generalizability of the results. In contrast, Rodahl et al. (21)
suggested that there were no systematic differences in aer-
obic power between white and nonwhite children. We were
unable to find other studies that have examined ethnicity and
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MEDICINE & SCIENCE IN SPORTS & EXERCISE
®
Copyright © 2002 by the American College of Sports Medicine
Submitted for publication November 2000.
Accepted for publication April 2001.
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