Physiological and perceptual responses at ventilatory threshold (VT) and V̇O2 peak were examined in 10 male children (10.2 ± 1.3 yrs) during graded treadmill and cycle exercise. Treadmill V̇O2peak (57.9 ± 6.7 ml · kg−1 · min−1) was higher (p < .05) than the cycle (51.7 ± 7.7 ml · kg−1 · min−1). Ventilation and heart rate (HR) were higher (p < .05) on the treadmill, while respiratory exchange ratio (RER), rating of perceived exertion (RPE), capillary blood lactate, and test duration were similar between tests. The V̇O2 at VT was higher (p < .05) on the treadmill (36.7 ± 4.6 ml · kg−1 · min−1) than the cycle (32.5 ± 4.4 ml · kg−1 · min−1). When VT was expressed as a percentage of V̇O2 peak, there was no difference (p > .05) between tests. The RPE at VT, HR at VT, and VT expressed as a percentage of HRpeak were also similar (p > .05) between tests. Similar to V̇O2 peak, the V̇O2 at VT is dependent on the mode of exercise. However, when VT is expressed as a percentage of V̇O2 peak, it is independent of testing modality. The RPE at VT appears to be linked to a percentage of V̇O2 peak rather than an absolute V̇O2.
Glen E. Duncan is with the Department of Exercise Science at the University of Tennessee, Knoxville, Knoxville, TN 37996. Anthony D. Mahon, Julie A. Gay, and Jennifer J. Sherwood are with the Human Performance Laboratory at Ball State University, Muncie, IN 47306. Request reprints from G.E. Duncan.