ORIGINAL ARTICLES   

The Journal of Sports Medicine and Physical Fitness 1998 September;38(3):227-33

Copyright © 1999 EDIZIONI MINERVA MEDICA

language: English

Predicting aerobic power in children. A comparison of two methods

McMurray R. G. ¹, Gunion W. K. ¹, Ainsworth B. E. ², Harrell J. S. ³

¹ Department of Physical Education, Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA; ² Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA; ³ School of Nursing, University of North Carolina, Chapel Hill, NC, USA

Objec­tive. To com­pare the accu­ra­cy of two equa­tions for pre­dict­ing V.O2max of chil­dren ­using sub­max­i­mal ­cycle ergom­e­try.
Experi­men­tal ­design. Repeat­ed meas­ures com­par­ing tread­mill meas­ured max­i­mal aero­bic pow­er (V.O2max) ­with two meth­ods of pre­dict­ing V.O2max ­using ­cycle ergom­e­try test­ing.
Par­tic­i­pants. Thir­ty-­three chil­dren (15 ­boys and 18 ­girls) ­aged 7-13 ­years ­served as sub­jects.
Meas­ures. ­Each ­child com­plet­ed a tread­mill grad­ed exer­cise ­test (GXT) to voli­tion­al ­fatigue to ­assess V.O2max. ­Each ­child ­also com­plet­ed a pro­gres­sive 9-min, ­three-­stage, sub­max­i­mal ­cycle ergom­e­ter ­test. ­Heart ­rates ­obtained dur­ing the ­last min­ute of ­each ­stage of the ergom­e­ter ­test ­were ­used to pre­dict V.O2max. Pre­dic­tions ­were ­based on a gen­der-spe­cif­ic mod­ifi­ca­tion of the PWC170 (­PWCGS) and a mod­ifi­ca­tion of the PWC195 ­using a 1.17 cor­rec­tion fac­tor and an age and gen­der-adjust­ed esti­mate of rest­ing meta­bol­ic ­rate.
­Results. The cor­re­la­tions ­between ­both sub­max­i­mal ­tests and the GXT ­were sig­nif­i­cant (p<0.001); how­ev­er, the cor­re­la­tion ­between the GXT and the PWC195 equa­tion (r=0.807) was high­er ­than the cor­re­la­tion ­between the GXT and the ­PWCGS equa­tion (r=0.658). Anal­y­sis indi­cat­ed ­that the ­PWCGS equa­tion sig­nif­i­cant­ly ­under-esti­mat­ed the V.O2max com­pared to ­either the GXT or PWC195 (GXT=45.0±7.1, PWC195=44.7±6.2, ­PWCGS=42.7±5.8 ml/kg/min; p<0.01).
Con­clu­sions. ­These ­results sug­gest ­that ­although the gen­der-spe­cif­ic ­PWCGS meth­od is easi­er to com­pute and may be accept­able, the mod­i­fied PWC195 meth­od is a ­more accu­rate esti­mate of V.O2max in chil­dren.