The purpose of this investigation was to determine whether aerobic fitness (VO2max) differed between black (N=40) and white (N=53) adolescent girls who were similar in age (13.5 yr) and percent body fat (24.6%). Expired gases were collected continuously while each girl performed a standard Bruce protocol to volitional exhaustion on a motorized treadmill (TM).
Heart rates (HR) were measured during the exercise testing via telemetry.
Fat-free mass (FFM) was estimated with total body electrical conductivity (TOBEC).
Average (± SD) maximum HR (black=194 ± 7 ; white=198 ± 8) and respiratory exchange ratios (black=1.17 ± 0.08 ; white=1.22 ± 0.09) did not differ between subject groups.
Aerobic fitness was significantly (P<0.01) lower in black versus white girls when VO2max was expressed relative to body weight (31.8 ± 5.8 vs 38.5 ± 6.8 ml. kg-1. min-1) and body weight raised to the 0.67 power (120.9 ± 19.5 vs 138.5 ± 20.7 ml. kg-0.67. min-1).
Treadmill time to exhaustion was significantly less (P<0.01) in the black (8.49 ± 1.30 min) versus white (9.41 ± 1.60) subjects.
Also, black subjects demonstrated less ability to utilize O2 during maximal exercise at a given FFM.
This suggests the black girls'FFM contained a smaller percentage of skeletal muscle mass that could be utilized during treadmill exercise.
It is possible that lower aerobic fitness values seen in the black girls are related to a combination of anatomical, physiological and/or behavioral factors.
Mots-clés Pascal : Femelle, Origine ethnique, Aptitude physique, Noir américain, Exercice physique, Epreuve tapis roulant, Etats Unis, Amérique du Nord, Amérique, Epidémiologie, Caucasoïde, Négroïde, Consommation oxygène maximum, Race, Adolescent, Homme
Mots-clés Pascal anglais : Female, Ethnic origin, Physical fitness, Black American, Physical exercise, Treadmill exercise, United States, North America, America, Epidemiology, Caucasoid, Negroid, Maximum oxygen consumption, Race, Adolescent, Human
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 96-0069793
Code Inist : 002B29A. Création : 199608.