Ventilatory threshold and maximal aerobic power in cycle ergometry in general persons, in relation to age and habitual physical activity
Shinichi TAMURA
This study measured ventilatory threshold (VT) and maximal aerobic power in a large group of subjects from the general population using a cycle ergometer. Fourteen hundred and thirty-four normal subjects (510 males and 924 females) underwent a series of physical fitness tests involving a maximal cycle ergometer test with breath-by-breath measurement of ventilation and gas exchange variables. The measured parameters were as follows, height, weight, 0fat estimated from skinfold thickness, leg extension power, oxygen uptake and power output at VT and exhaustion (Wmax). These subjects were classified by the habitual physical activity into two categories, Ex group and Goot group. The mean and SD of each parameter were calculated for five 10-year age groups subdivided by males and females. Oxygen uptake at VT ('~o2@VT) and Wmax (Vo2@Wmax) varied with age. Regression of Vo2 @VT on age in males was described by the equation:Vo2@VT (mi/kg/mm) =24.6-0.153xAGE (SEE= 4.3, r=0.385). Regression of Vo2@Wmax on agein males was described hy the equation : (~o2@Wmax (mi/kg/mm) =41.3-0.271x AGE (SEE= 5.8,r~0.474), and in females, Vo2@VT (mi/kg/mm) =19.8-0.0934xAGE (SEE=3.2, r=0.317), Vo2@Wmax (mi/kg/mm) = 31.2-0.0160 x AGE (SEE=4.5, r=0.380), respectively. Habitual physical activity was beneficially associated with VT and Wmax in males and females, and with legextension power relative to body weight in females.
