Cardiovascular Fitness in Premenarcheal Girls and Young Women

Maximal oxygen uptake (V˙O₂max) in females, expressed as ml × kg^-1 × min^-1, declines steadily during the first three decades of life. The contribution of diminished cardiovascular function to this apparent fall in aerobic fitness is unknown. Cardiac responses to maximal cycle exercise were compared in 24 premenarcheal females (mean age 11.7 years) and 17 young adult women (mean age 27.4 years) using Doppler echocardiography. Mean V˙O₂max was 40 ml × kg^-1 × min^-1 and 34.7 ml × kg^-1 × min^-1 in the girls and women, respectively (p < 0.05). When V˙O₂max was expressed relative to allometrically-derived mass^0.52, however, no significant difference was observed in aerobic fitness between the two groups. Similar allometric analyses revealed no significant differences in average maximal cardiac output (10.50 vs 10.07 L × min^-1 BSA^-1.11 for girls and women, respectively) nor maximal stroke volume (53 vs 56 ml BSA^-1.13 respectively). These findings suggest that 1) allometric scaling is important in eliminating the effects of body size on V˙O₂max, 2) body dimension differences can account for variations in V˙O₂ in young females, and 3) cardiac functional reserve is similar in premenarcheal girls and young adult women.

Key words:

Children - fitness - oxygen uptake - cardiac output

References

• 1 Armstrong N, Welsman J R. Assessment and interpretation of aerobic fitness in children and adolescents.  Exerc Sports Science Rev. 1994;  22 435-476
• 2 Bar-Or O. Pediatric Sports Medicine for the Practioner. New York; Springer-Verlag 1983: 4-6
• 3 Cooper D M, Weiler-Ravell D, Whipp B J, Wasserman K. Aerobic parameters of exercise as a function of body size during growth in children.  J Appl Physiol. 1984;  56 628-634
• 4 Drinkwater B L. Women and exercise: physiological aspects.  Exerc Sport Science Rev. 1984;  12 21-51
• 5 Drinkwater B L, Horvath S M, Wells C L. Aerobic power of females, ages 10 to 68.  J Gerontol. 1975;  30 385-394
• 6 Kemper H CG, Verschuur R, de May L. Longitudinal changes in aerobic fitness in youth ages 12 to 23.  Pediatr Exerc Science. 1989;  1 257-270
• 7 Krahenbuhl G S, Skinner J S, Kohrt W M. Developmental aspects of maximal aerobic power in children.  Exerc Sport Science Rev. 1985;  13 503-538
• 8 Lohman T G. Advances in Body Composition Assessment. Champaign, IL; Human Kinetics Publishers 1992
• 9 Martin A D, Ward R. Body composition. In: Docherty D (ed) Measurement in Pediatric Exercise Science. Champaign, IL; Human Kinetics Publishers 1996: 87-128
• 10 Miyamura M, Honda Y. Maximum cardiac output related to sex and age.  Jpn J Physiol. 1973;  23 645-656
• 11 Rogers D M, Turley K Y, Kujawa K I, Harper K M, Wilmore J H. Allometric scaling factors for oxygen uptake during exercise in children.  Pediatr Exerc Science. 1995;  7 12-25
• 12 Rowland T W. Developmental Exercise Physiology. Champaign, IL; Human Kinetics Publishers 1996: 132-133
• 13 Rowland T W, Green G M. Physiological responses to treadmill exercise in females: adult-child differences.  Med Sci Sports Exerc. 1988;  20 474-478
• 14 Rowland T, Melanson E, Popowski B, Ferrone L. Test-retest reproducibility of maximal cardiac output by Doppler echocardiography.  Am J Cardiol. 1998;  81 1228-1230
• 15 Rowland T, Popowski B. Comparison of bioimpedance and Doppler cardiac output during exercise in children (abstract).  Pediatr Exerc Science. 1997;  9 188
• 16 Rowland T, Popowski B, Ferrone L. Cardiac responses to maximal upright cycle exercise in healthy boys and men.  Med Sci Sports Exerc. 1997;  29 1146-1151
• 17 Rowland T W, Rimany T A. Physiological responses to prolonged exercise in premenarcheal and adult females.  Pediatr Exerc Science. 1995;  7 183-191
• 18 Rowland T W, Vanderburgh P, Cunningham L. Body size and the growth of maximal aerobic power in children: A longitudinal analysis.  Pediatr Exerc Science. 1997;  9 262-274
• 19 Skaerpe T, Hegrenaes L, Ihlen H. Cardiac output. In: Hatle L, Angelsen B (eds) Doppler Ultrasound in Cardiology. Philadelphia; Lea & Febiger 1992: 306-320
• 20 Turley K R, Wilmore J H. Cardiovascular responses to treadmill and cycle ergometer exercise in children and adults.  J Appl Physiol. 1997;  83 948-957
• 21 Vanderburgh P M. Two important cautions in the use of allometric scaling: The common exponent and group difference principles.  Meas Phys Ed Exerc Science. 1998;  2 153-163
• 22 Welsman J, Armstrong N. The interpretation of peak volume oxygen (V˙O₂) in prepubertal children. In: Ring FJ (ed) Children in Sport Bath. Centre for Continuing Education 1995: 64-69
• 23 Welsman J R, Armstrong N, Nevill A M, Winter E M, Kirby B J. Scaling peak V˙O₂ for differences in body size.  Med Sci Sports Exerc. 1996;  28 259-265
• 24 Welsman J, Armstrong N, Winter E, Kirby B J. The influence of various scaling techniques on the interpretation of developmental changes in peak V˙O₂ (abstract).  Pediatr Exerc Science. 1993;  5 485
• 25 Wilmore J H, Costill D L. Physiology of Sport and Exercise. Champaign, IL; Human Kinetic Publishers 1994